@article{hostettere_gardner_sillett_pollock_simons_2019, title={An integrated model decomposing the components of detection probability and abundance in unmarked populations}, volume={10}, ISSN={["2150-8925"]}, url={https://doi.org/10.1002/ecs2.2586}, DOI={10.1002/ecs2.2586}, abstractNote={Accurate estimates of population abundance are essential to both theoretical and applied ecology. Rarely are all individuals detected during a survey and abundance models often incorporate some form of imperfect detection. Detection probability, however, consists of three components: probability of presence during a survey, probability of availability given presence, and probability of detection given availability and presence. We develop an integrated model to separate these three detection components and provide abundance estimates for the available, present, and superpopulation of individuals. Our framework integrates several common survey methods for unmarked populations: spatially and temporally replicated counts, distance sampling data, and time-of-detection data. Simulations indicated relatively unbiased estimates for detection and availability probabilities. Negative bias in estimated superpopulation abundance was present with three temporally replicated surveys, but greatly reduced with six surveys. In a case study of Island Scrub-Jays (Aphelocoma insularis), posterior modes for presence, availability, and detection probabilities were 0.78, 0.96, and 0.26, respectively, from 10-min point counts repeated at 97 sites on three occasions, with noticeable differences among available, present, and superpopulation abundance estimates. This generalizable framework integrates common sampling protocols and provides joint inferences on the components of detection probability, spatial and non-spatial temporary emigration, and abundance in unmarked populations.}, number={3}, journal={ECOSPHERE}, publisher={Wiley}, author={Hostettere, Nathan J. and Gardner, Beth and Sillett, T. Scott and Pollock, Kenneth H. and Simons, Theodore R.}, year={2019}, month={Mar} }
 @article{collazo_krachey_pollock_perez-aguilo_zegarra_mignucci-giannoni_2019, title={Population estimates of Antillean manatees in Puerto Rico: an analytical framework for aerial surveys using multi-pass removal sampling}, volume={100}, ISSN={["1545-1542"]}, DOI={10.1093/jmammal/gyz076}, abstractNote={Abstract Effective management of the threatened Antillean manatee (Trichechus manatus manatus) in Puerto Rico requires reliable estimates of population size. Estimates are needed to assess population responses to management actions, and whether recovery objectives have been met. Aerial surveys have been conducted since 1976, but none adjusted for imperfect detection. We summarize surveys since 1976, report on current distribution, and provide population estimates after accounting for apparent detection probability for surveys between June 2010 and March 2014. Estimates in areas of high concentration (hotspots) averaged 317 ± 101, three times higher than unadjusted counts (104 ± 0.56). Adjusted estimates in three areas outside hotspots also differed markedly from counts (75 ± 9.89 versus 19.5 ± 3.5). Average minimum island-wide estimate was 386 ± 89, similar to the maximum estimate of 360 suggested in 2005, but fewer than the 700 recently suggested by the Puerto Rico Manatee Conservation Center. Manatees were more widespread than previously understood. Improving estimates, locally or island-wide, will require stratifying the island differently and greater knowledge about factors affecting detection probability. Sharing our protocol with partners in nearby islands (e.g., Cuba, Jamaica, Hispaniola), whose populations share genetic make-up, would contribute to enhanced regional conservation through better population estimates and tracking range expansion. El manejo efectivo del manatí antillano amenazado en Puerto Rico requiere estimados de tamaños de poblaciónes confiables. Dichas estimaciones poblacionales son necesarias para evaluar las respuestas a las acciones de manejo, y para determinar si los objetivos de recuperación han sido alcanzados. Se han realizado censos aéreos desde 1976, pero ninguno de ellos han sido ajustados para detecciones imperfectas. Aquí resumimos los censos desde 1976, actualizamos la distribución, y reportamos los primeros estimados poblacionales ajustados para la probabilidad de detección aparente en los censos de Junio 2010 a Marzo 2014. Las estimaciones poblacionales en áreas de mayor concentración del manatí promedió 317 ± 103, tres veces más abundante que los conteos sin ajuste (104 ± 0.56). Las estimaciones poblacionales en tres áreas fuera de las áreas de mayor concentración del manatí también fueron marcadamente diferentes (75 ± 9.89 vs 19.5 ± 3.5). El estimado mínimo poblacional en la isla entera fue de 386 ± 89, similar al estimado máximo de 360 sugerido en el año 2005, pero menor a los 700 sugeridos recientemente por el Centro de Conservación de Manatíes de Puerto Rico. Documentamos que el manatí tiene una distribución más amplia de lo que se sabía con anterioridad. El mejoramiento de los estimados poblacionales locales o a nivel de isla requerirá que se estratifique a la isla en forma diferente y que se investiguen los factores que influencian a la probabilidad de detección. Compartir protocolos como este con colaboradores de islas vecinas (por. ej., Cuba, Jamaica, Española), cuyas poblaciones de manatíes comparten material genético, contribuiría a la conservación regional mediante mejores estimaciones poblacionales y monitoreo de la expansión de su ámbito doméstico.}, number={4}, journal={JOURNAL OF MAMMALOGY}, author={Collazo, Jaime A. and Krachey, Matthew J. and Pollock, Kenneth H. and Perez-Aguilo, Francisco J. and Zegarra, Jan P. and Mignucci-Giannoni, Antonio A.}, year={2019}, month={Jul}, pages={1340–1349} }
 @article{hupman_stockin_pollock_pawley_dwyer_lea_tezanos-pinto_2018, title={Challenges of implementing Mark-recapture studies on poorly marked gregarious delphinids}, volume={13}, number={7}, journal={PLoS One}, author={Hupman, K. and Stockin, K. A. and Pollock, K. and Pawley, M. D. M. and Dwyer, S. L. and Lea, C. and Tezanos-Pinto, G.}, year={2018} }
 @article{hupman_stockin_pollock_pawley_dwyer_lea_tezanos-pinto_2018, title={Challenges of implementing Mark-recapture studies on poorly marked gregarious delphinids (vol 13, e0198167, 2018)}, volume={13}, ISSN={["1932-6203"]}, DOI={10.1371/journal.pone.0203356}, abstractNote={[This corrects the article DOI: 10.1371/journal.pone.0198167.].}, number={8}, journal={PLOS ONE}, author={Hupman, Krista and Stockin, Karen A. and Pollock, Kenneth and Pawley, Matthew D. M. and Dwyer, Sarah L. and Lea, Catherine and Tezanos-Pinto, Gabriela}, year={2018}, month={Aug} }
 @article{felton_pollock_simons_2018, title={Response of beach-nesting American Oystercatchers to off-road vehicles: An experimental approach reveals physiological nuances and decreased nest attendance}, volume={120}, ISSN={0010-5422 1938-5129}, url={http://dx.doi.org/10.1650/CONDOR-17-84.1}, DOI={10.1650/condor-17-84.1}, abstractNote={ABSTRACT Shorebird populations face increasing challenges as rising sea levels and growing human populations constrain their breeding habitats. On recreational beaches, the nesting season often coincides with a season of high visitor use, increasing the potential for conflict, which may negatively influence beach-nesting shorebird species. We designed a field experiment to study the responses of nesting American Oystercatchers (Haematopus palliatus) to off-road passenger vehicles (ORVs) at Cape Hatteras and Cape Lookout National Seashores in North Carolina, USA. We used continuous video and heart rate recordings to assess changes in the behavior and physiology of incubating oystercatchers. We conducted driving experiments affecting 7 nesting pairs in 2014 and 19 nesting pairs in 2015, between April and July of each year. Experimental treatments were repeated throughout the incubation period for each nest. Although responses were highly variable within and among pairs, paired randomized permutation tests i...}, number={1}, journal={The Condor}, publisher={Oxford University Press (OUP)}, author={Felton, Shilo K. and Pollock, Kenneth H. and Simons, Theodore R.}, year={2018}, month={Feb}, pages={47–62} }
 @article{chabanne_pollock_finn_bejder_2017, title={Applying the multistate capture-recapture robust design to characterize metapopulation structure}, volume={8}, ISSN={["2041-2096"]}, DOI={10.1111/2041-210x.12792}, abstractNote={Summary Population structure must be considered when developing mark–recapture (MR) study designs as the sampling of individuals from multiple populations (or subpopulations) may increase heterogeneity in individual capture probability. Conversely, the use of an appropriate MR study design which accommodates heterogeneity associated with capture occasion varying covariates due to animals moving between ‘states’ (i.e. geographic sites) can provide insight into how animals are distributed in a particular environment and the status and connectivity of subpopulations. The multistate closed robust design (MSCRD) was chosen to investigate: (i) the demographic parameters of Indo‐Pacific bottlenose dolphin ( Tursiops aduncus ) subpopulations in coastal and estuarine waters of Perth, Western Australia; and (ii) how they are related to each other in a metapopulation. Using 4 years of year‐round photo‐identification surveys across three geographic sites, we accounted for heterogeneity of capture probability based on how individuals distributed themselves across geographic sites and characterized the status of subpopulations based on their abundance, survival and interconnection. MSCRD models highlighted high heterogeneity in capture probabilities and demographic parameters between sites. High capture probabilities, high survival and constant abundances described a subpopulation with high fidelity in an estuary. In contrast, low captures, permanent and temporary emigration and fluctuating abundances suggested transient use and low fidelity in an open coastline site. Estimates of transition probabilities also varied between sites, with estuarine dolphins visiting sheltered coastal embayments more regularly than coastal dolphins visited the estuary, highlighting some dynamics within the metapopulation. Synthesis and applications . To date, bottlenose dolphin studies using mark–recapture approach have focussed on investigating single subpopulations. Here, in a heterogeneous coastal–estuarine environment, we demonstrated that spatially structured bottlenose dolphin subpopulations contained distinct suites of individuals and differed in size, demographics and connectivity. Such insights into the dynamics of a metapopulation can assist in local‐scale species conservation. The MSCRD approach is applicable to species/populations consisting of recognizable individuals and is particularly useful for characterizing wildlife subpopulations that vary in their vulnerability to human activities, climate change or invasive species.}, number={11}, journal={METHODS IN ECOLOGY AND EVOLUTION}, author={Chabanne, Delphine B. H. and Pollock, Kenneth H. and Finn, Hugh and Bejder, Lars}, year={2017}, month={Nov}, pages={1547–1557} }
 @article{felton_hostetter_pollock_simons_2017, title={Managing American Oystercatcher (Haematopus palliatus) Population Growth by Targeting Nesting Season Vital Rates}, volume={40}, ISSN={1524-4695 1938-5390}, url={http://dx.doi.org/10.1675/063.040.sp106}, DOI={10.1675/063.040.sp106}, abstractNote={In populations of long-lived species, adult survival typically has a relatively high influence on population growth. From a management perspective, however, adult survival can be difficult to increase in some instances, so other component rates must be considered to reverse population declines. In North Carolina, USA, management to conserve the American Oystercatcher (Haematopus palliatus) targets component vital rates related to fecundity, specifically nest and chick survival. The effectiveness of such a management approach in North Carolina was assessed by creating a three-stage female-based deterministic matrix model. Isoclines were produced from the matrix model to evaluate minimum nest and chick survival rates necessary to reverse population decline, assuming all other vital rates remained stable at mean values. Assuming accurate vital rates, breeding populations within North Carolina appear to be declining. To reverse this decline, combined nest and chick survival would need to increase from 0.14 to ≤ 0.27, a rate that appears to be attainable based on historical estimates. Results are heavily dependent on assumptions of other vital rates, most notably adult survival, revealing the need for accurate estimates of all vital rates to inform management actions. This approach provides valuable insights for evaluating conservation goals for species of concern.}, number={sp1}, journal={Waterbirds}, publisher={Waterbird Society}, author={Felton, Shilo K. and Hostetter, Nathan J. and Pollock, Kenneth H. and Simons, Theodore R.}, year={2017}, month={Feb}, pages={44–54} }
 @article{allen_pollock_bouchet_kobryn_mcelligott_nicholson_smith_loneragan_2017, title={Preliminary estimates of the abundance and fidelity of dolphins associating with a demersal trawl fishery}, volume={7}, ISSN={2045-2322}, url={http://dx.doi.org/10.1038/S41598-017-05189-0}, DOI={10.1038/S41598-017-05189-0}, abstractNote={Abstract The incidental capture of wildlife in fishing gear presents a global conservation challenge. As a baseline to inform assessments of the impact of bycatch on bottlenose dolphins ( Tursiops truncatus ) interacting with an Australian trawl fishery, we conducted an aerial survey to estimate dolphin abundance across the fishery. Concurrently, we carried out boat-based dolphin photo-identification to assess short-term fidelity to foraging around trawlers, and used photographic and genetic data to infer longer-term fidelity to the fishery. We estimated abundance at ≈ 2,300 dolphins (95% CI = 1,247–4,214) over the ≈ 25,880-km 2 fishery. Mark-recapture estimates yielded 226 (SE = 38.5) dolphins associating with one trawler and some individuals photographed up to seven times over 12 capture periods. Moreover, photographic and genetic re-sampling over three years confirmed that some individuals show long-term fidelity to trawler-associated foraging. Our study presents the first abundance estimate for any Australian pelagic dolphin community and documents individuals associating with trawlers over days, months and years. Without trend data or correction factors for dolphin availability, the impact of bycatch on this dolphin population’s conservation status remains unknown. These results should be taken into account by management agencies assessing the impact of fisheries-related mortality on this protected species.}, number={1}, journal={Scientific Reports}, publisher={Springer Science and Business Media LLC}, author={Allen, Simon J. and Pollock, Kenneth H. and Bouchet, Phil J. and Kobryn, Halina T. and McElligott, Deirdre B. and Nicholson, Krista E. and Smith, Joshua N. and Loneragan, Neil R.}, year={2017}, month={Jul} }
 @article{hall_adams_bradley_bryant_davis_dickman_fujita_kobayashi_lepczyk_mcbride_et al._2016, title={Community attitudes and practices of urban residents regarding predation by pet cats on wildlife: An international comparison}, volume={11}, number={4}, journal={PLoS One}, author={Hall, C. M. and Adams, N. A. and Bradley, J. S. and Bryant, K. A. and Davis, A. A. and Dickman, C. R. and Fujita, T. and Kobayashi, S. and Lepczyk, C. A. and McBride, E. A. and et al.}, year={2016} }
 @article{tyne_loneragan_johnston_pollock_williams_bejder_2016, title={Evaluating monitoring methods for cetaceans}, volume={201}, ISSN={["1873-2917"]}, DOI={10.1016/j.biocon.2016.07.024}, abstractNote={With increasing human pressures on wildlife comes a responsibility to monitor them effectively, particularly in an environment of declining research funds. Scarce funding resources compromise the level and efficacy of monitoring possible to detect trends in abundance, highlighting the priority for developing cost-effective programs. A systematic and rigorous sampling regime was developed to estimate abundance of a small, genetically isolated spinner dolphin (Stenella longirostris) population exposed to high levels of human activities. Five monitoring scenarios to detect trends in abundance were evaluated by varying sampling effort, precision, power, and sampling interval. Scenario 1 consisted of monthly surveys, each of 12 days, used to obtain the initial two consecutive annual abundance estimates. Scenarios 2, 3, and 4 consisted of a reduced effort, while Scenario 5 doubled the effort of Scenario 1. Scenarios with the greatest effort (1 and 5) produced the most precise abundance estimates (CV = 0.09). Using a CV = 0.09 and power of 80%, it would take 9 years to detect a 5% annual change in abundance compared with 12 years at a power of 95%. Under this best-case monitoring scenario, if the trend was a decline, the population would have decreased by 37% and 46%, respectively, prior to detection of a significant decline. With the potential of a large decline in a small population prior to detection, the lower power level should be used to trigger a management intervention. The approach presented here is applicable across taxa for which individuals can be identified, including terrestrial and aquatic mammals, birds, and reptiles.}, journal={BIOLOGICAL CONSERVATION}, author={Tyne, Julian A. and Loneragan, Neil R. and Johnston, David W. and Pollock, Kenneth H. and Williams, Rob and Bejder, Lars}, year={2016}, month={Sep}, pages={252–260} }
 @article{stevenson_chitwood_lashley_pollock_swingen_moorman_deperno_2016, title={Survival and Cause-Specific Mortality of Coyotes on a Large Military Installation}, volume={15}, ISSN={["1938-5412"]}, DOI={10.1656/058.015.0307}, abstractNote={Canis latrans (Coyote) recently expanded into the southeastern United States, creating ecologically novel interactions with other species. However, relatively few studies have examined vital rates of southeastern Coyotes or estimated vital rates where individuals are protected from hunting and trapping. In 2011, we captured and attached GPS radiocollars to 31 Coyotes at Fort Bragg Military Installation, NC, where Coyote harvest was restricted. We used a 12-month period (February 2011–January 2012) and known-fate modeling in Program MARK to estimate annual survival. Model-selection results indicated the time-varying model (S[t]) was the most parsimonious model, and. annual survival was 0.80 (95% CI = 0.60–0.91). We documented 7 mortalities, including 2 from vehicles, 2 from offsite trapping, and 3 from unknown causes. Estimated Coyote survival rates at Fort Bragg were similar to most other estimates from the southeastern US. Anthropogenic causes of mortality were important even though hunting and trapping were restricted locally.}, number={3}, journal={SOUTHEASTERN NATURALIST}, author={Stevenson, Elizabeth R. and Chitwood, M. Colter and Lashley, Marcus A. and Pollock, Kenneth H. and Swingen, Morgan B. and Moorman, Christopher E. and DePerno, Christopher S.}, year={2016}, month={Sep}, pages={459–466} }
 @article{wayne_maxwell_ward_vellios_williams_pollock_2016, title={The responses of a critically endangered mycophagous marsupial (Bettongia penicillata) to timber harvesting in a native eucalypt forest}, volume={363}, ISSN={["1872-7042"]}, DOI={10.1016/j.foreco.2015.12.019}, abstractNote={Mycophagous bioturbators provide ecosystem services that can be important for the resilience and restoration of ecosystems. Among the Australian mammals, mycophagy is most prevalent within the Potoroidae (bettongs and potoroos). However, proportionally more species of Potoroidae are either recently extinct or currently threatened than any other mammalian family in Australia, and they are among the least studied. The critically endangered woylie, or brush-tailed bettong (Bettongia penicillata), is a mycophagous, ground dwelling ‘ecosystem engineer’ that was one of Australia’s most abundant and widely distributed potoroids prior to European settlement. After substantial range contraction, however, the remaining indigenous populations are now restricted to eucalypt forests in south-western Australia. Using an experimental approach, we investigated the population responses of the woylie to timber harvesting in these forests. Nine treatments, including varying logging intensities and unharvested controls, were applied at 22 sites. The abundance of the woylie in the harvested areas, in unharvested stands between logged areas, and in extensive unharvested stands outside the harvest management area were compared using a replicated before-after-control-impact (BACI) repeated measures design and capture-mark-recapture modelling. A total of 5860 captures of 815 individuals were recorded during 35 trapping sessions over 16 years (one year preceding, two years during, and 13 years after disturbance). Capture rate was a good index of abundance for this species and woylie abundance, survivorship and recruitment were not adversely affected by silvicultural practices in the jarrah (Eucalyptus marginata) forest. On the contrary, the harvested areas may have afforded some localised protection when an unrelated, species-wide decline began three years after harvesting disturbance ended; woylie numbers declined by up to 77% and 95% in harvested and unharvested areas, respectively. Thus the nature and spatial extent of the timber harvesting regimes investigated in this study were not a major threatening process for this species. However, ongoing monitoring and evaluation are necessary to ensure that timber harvesting activities remain benign in the face of a changing climate, possible increased mortality from introduced predators, disease, and further declines in the abundance of this critically endangered marsupial.}, journal={FOREST ECOLOGY AND MANAGEMENT}, author={Wayne, Adrian F. and Maxwell, Marika A. and Ward, Colin G. and Vellios, Christos V. and Williams, Matthew R. and Pollock, Kenneth H.}, year={2016}, month={Mar}, pages={190–199} }
 @article{jones_bull_brook_wells_pollock_fordham_2016, title={Tick exposure and extreme climate events impact survival and threaten the persistence of a long-lived lizard}, volume={85}, ISSN={["1365-2656"]}, DOI={10.1111/1365-2656.12469}, abstractNote={Assessing the impacts of multiple, often synergistic, stressors on the population dynamics of long-lived species is becoming increasingly important due to recent and future global change. Tiliqua rugosa (sleepy lizard) is a long-lived skink (>30 years) that is adapted to survive in semi-arid environments with varying levels of parasite exposure and highly seasonal food availability. We used an exhaustive database of 30 years of capture–mark–recapture records to quantify the impacts of both parasite exposure and environmental conditions on the lizard's survival rates and long-term population dynamics. Lizard abundance was relatively stable throughout the study period; however, there were changing patterns in adult and juvenile apparent survival rates, driven by spatial and temporal variation in levels of tick exposure and temporal variation in environmental conditions. Extreme weather events during the winter and spring seasons were identified as important environmental drivers of survival. Climate models predict a dramatic increase in the frequency of extreme hot and dry winter and spring seasons in our South Australian study region; from a contemporary probability of 0·17 up to 0·47–0·83 in 2080 depending on the emissions scenario. Our stochastic population model projections showed that these future climatic conditions will induce a decline in the abundance of this long-lived reptile of up to 67% within 30 years from 2080, under worst case scenario modelling. The results have broad implications for future work investigating the drivers of population dynamics and persistence. We highlight the importance of long-term data sets and accounting for synergistic impacts between multiple stressors. We show that predicted increases in the frequency of extreme climate events have the potential to considerably and negatively influence a long-lived species, which might previously have been assumed to be resilient to environmental perturbations.}, number={2}, journal={JOURNAL OF ANIMAL ECOLOGY}, author={Jones, Alice R. and Bull, C. Michael and Brook, Barry W. and Wells, Konstans and Pollock, Kenneth H. and Fordham, Damien A.}, year={2016}, month={Mar}, pages={598–610} }
 @article{parsons_simons_pollock_stoskopf_stocking_o'connell_2015, title={Camera traps and mark-resight models: The value of ancillary data for evaluating assumptions}, volume={79}, ISSN={0022-541X}, url={http://dx.doi.org/10.1002/JWMG.931}, DOI={10.1002/JWMG.931}, abstractNote={Unbiased estimators of abundance and density are fundamental to the study of animal ecology and critical for making sound management decisions. Capture–recapture models are generally considered the most robust approach for estimating these parameters but rely on a number of assumptions that are often violated but rarely validated. Mark-resight models, a form of capture–recapture, are well suited for use with noninvasive sampling methods and allow for a number of assumptions to be relaxed. We used ancillary data from continuous video and radio telemetry to evaluate the assumptions of mark-resight models for abundance estimation on a barrier island raccoon (Procyon lotor) population using camera traps. Our island study site was geographically closed, allowing us to estimate real survival and in situ recruitment in addition to population size. We found several sources of bias due to heterogeneity of capture probabilities in our study, including camera placement, animal movement, island physiography, and animal behavior. Almost all sources of heterogeneity could be accounted for using the sophisticated mark-resight models developed by McClintock et al. (2009b) and this model generated estimates similar to a spatially explicit mark-resight model previously developed for this population during our study. Spatially explicit capture–recapture models have become an important tool in ecology and confer a number of advantages; however, non-spatial models that account for inherent individual heterogeneity may perform nearly as well, especially where immigration and emigration are limited. Non-spatial models are computationally less demanding, do not make implicit assumptions related to the isotropy of home ranges, and can provide insights with respect to the biological traits of the local population. © 2015 The Wildlife Society.}, number={7}, journal={The Journal of Wildlife Management}, publisher={Wiley}, author={Parsons, Arielle W. and Simons, Theodore R. and Pollock, Kenneth H. and Stoskopf, Michael K. and Stocking, Jessica J. and O'connell, Allan F., Jr.}, year={2015}, month={Aug}, pages={1163–1172} }
 @article{chitwood_lashley_kilgo_pollock_moorman_deperno_2015, title={Do Biological and Bedsite Characteristics Influence Survival of Neonatal White-Tailed Deer?}, volume={10}, ISSN={1932-6203}, url={http://dx.doi.org/10.1371/journal.pone.0119070}, DOI={10.1371/journal.pone.0119070}, abstractNote={Coyotes recently expanded into the eastern U.S. and potentially have caused localized white-tailed deer population declines. Research has focused on quantifying coyote predation on neonates, but little research has addressed the potential influence of bedsite characteristics on survival. In 2011 and 2012, we radiocollared 65 neonates, monitored them intensively for 16 weeks, and assigned mortality causes. We used Program MARK to estimate survival to 16 weeks and included biological covariates (i.e., sex, sibling status [whether or not it had a sibling], birth weight, and Julian date of birth). Survival to 16 weeks was 0.141 (95% CI = 0.075-0.249) and the top model included only sibling status, which indicated survival was lower for neonates that had a sibling. Predation was the leading cause of mortality (35 of 55; 64%) and coyotes were responsible for the majority of depredations (30 of 35; 86%). Additionally, we relocated neonates for the first 10 days of life and measured distance to firebreak, visual obstruction, and plant diversity at bedsites. Survival of predation to 10 days (0.726; 95% CI = 0.586-0.833) was weakly associated with plant diversity at bedsites but not related to visual obstruction. Our results indicate that neonate survival was low and coyote predation was an important source of mortality, which corroborates several recent studies from the region. Additionally, we detected only weak support for bedsite cover as a covariate to neonate survival, which indicates that mitigating effects of coyote predation on neonates may be more complicated than simply managing for increased hiding cover.}, number={3}, journal={PLOS ONE}, publisher={Public Library of Science (PLoS)}, author={Chitwood, M. Colter and Lashley, Marcus A. and Kilgo, John C. and Pollock, Kenneth H. and Moorman, Christopher E. and DePerno, Christopher S.}, editor={Roca, Alfred L.Editor}, year={2015}, month={Mar}, pages={e0119070} }
 @article{hayward_boitani_burrows_funston_karanth_mackenzie_pollock_yarnell_2015, title={Ecologists need robust survey designs, sampling and analytical methods}, volume={52}, ISSN={["1365-2664"]}, DOI={10.1111/1365-2664.12408}, abstractNote={Research that yields conflicting results rightly causes controversy. Where methodological weaknesses are apparent, there is ready opportunity for discord within the scientific community, which may undermine the entire study. We use the debate about the role of dingoes Canis dingo in conservation in Australia as a case study for a phenomenon that is relevant to all applied ecologists, where conflicting results have been published in high-quality journals and yet the problems with the methods used in these studies have led to significant controversy. To alleviate such controversies, scientists need to use robust methods to ensure that their results are repeatable and defendable. To date, this has not occurred in Australia's dingo debate due to the use of unvalidated indices that rely on unsupported assumptions. We highlight the problems that poor methods have caused in this debate. We also reiterate our recommendations for practitioners, statisticians and researchers to work together to develop long-term, multi-site experimental research programmes using robust methods to understand the impacts of dingoes on mesopredators. Synthesis and applications. Incorporating robust methods and appropriate experimental designs is needed to ensure that conservation actions are appropriately focused and are supported with robust results. Such actions will go a long way towards resolving the debate about the role of dingoes in conservation in Australia, and other, ecological debates.}, number={2}, journal={JOURNAL OF APPLIED ECOLOGY}, author={Hayward, Matt W. and Boitani, Luigi and Burrows, Neil D. and Funston, Paul J. and Karanth, K. Ullas and MacKenzie, Darryl I. and Pollock, Ken H. and Yarnell, Richard W.}, year={2015}, month={Apr}, pages={286–290} }
 @article{dudgeon_pollock_braccini_semmens_barnett_2015, title={Integrating acoustic telemetry into mark-recapture models to improve the precision of apparent survival and abundance estimates}, volume={178}, ISSN={["1432-1939"]}, DOI={10.1007/s00442-015-3280-z}, number={3}, journal={OECOLOGIA}, author={Dudgeon, Christine L. and Pollock, Kenneth H. and Braccini, J. Matias and Semmens, Jayson M. and Barnett, Adam}, year={2015}, month={Jul}, pages={761–772} }
 @article{hostetter_gardner_schweitzer_boettcher_wilke_addison_swilling_pollock_simons_2015, title={Repeated count surveys help standardize multi-agency estimates of American Oystercatcher (Haematopus palliatus) abundance}, volume={117}, ISSN={0010-5422 1938-5129}, url={http://dx.doi.org/10.1650/CONDOR-14-185.1}, DOI={10.1650/condor-14-185.1}, abstractNote={The extensive breeding range of many shorebird species can make integration of survey data problematic at regional spatial scales. We evaluated the effectiveness of standardized repeated count surveys coordinated across 8 agencies to estimate the abundance of American Oystercatcher (Haematopus palliatus) breeding pairs in the southeastern United States. Breeding season surveys were conducted across coastal North Carolina (90 plots) and the Eastern Shore of Virginia (3 plots). Plots were visited on 1–5 occasions during April–June 2013. N-mixture models were used to estimate abundance and detection probability in relation to survey date, tide stage, plot size, and plot location (coastal bay vs. barrier island). The estimated abundance of oystercatchers in the surveyed area was 1,048 individuals (95% credible interval: 851–1,408) and 470 pairs (384–637), substantially higher than estimates that did not account for detection probability (maximum counts of 674 individuals and 316 pairs). Detection probability was influenced by a quadratic function of survey date, and increased from mid-April (~0.60) to mid-May (~0.80), then remained relatively constant through June. Detection probability was also higher during high tide than during low, rising, or falling tides. Abundance estimates from N-mixture models were validated at 13 plots by exhaustive productivity studies (2–5 surveys wk−1). Intensive productivity studies identified 78 breeding pairs across 13 productivity plots while the N-mixture model abundance estimate was 74 pairs (62–119) using only 1–5 replicated surveys season−1. Our results indicate that standardized replicated count surveys coordinated across multiple agencies and conducted during a relatively short time window (closure assumption) provide tremendous potential to meet both agency-level (e.g., state) and regional-level (e.g., flyway) objectives in large-scale shorebird monitoring programs.}, number={3}, journal={The Condor}, publisher={Oxford University Press (OUP)}, author={Hostetter, Nathan J. and Gardner, Beth and Schweitzer, Sara H. and Boettcher, Ruth and Wilke, Alexandra L. and Addison, Lindsay and Swilling, William R. and Pollock, Kenneth H. and Simons, Theodore R.}, year={2015}, month={Aug}, pages={354–363} }
 @article{wen_nichols_pollock_waser_2014, title={A robust design capture-recapture model with multiple age classes augmented with population assignment data}, volume={21}, ISSN={["1573-3009"]}, DOI={10.1007/s10651-013-0243-6}, number={1}, journal={ENVIRONMENTAL AND ECOLOGICAL STATISTICS}, author={Wen, Zhi and Nichols, James D. and Pollock, Kenneth H. and Waser, Peter M.}, year={2014}, month={Mar}, pages={41–59} }
 @article{tyne_pollock_johnston_bejder_2014, title={Abundance and survival rates of the Hawai'i Island associated spinner dolphin (Stenella longirostris) stock}, volume={9}, number={1}, journal={PLoS One}, author={Tyne, J. A. and Pollock, K. H. and Johnston, D. W. and Bejder, L.}, year={2014} }
 @article{allen_tyne_kobryn_bejder_pollock_loneragan_2014, title={Patterns of dolphin bycatch in a North-Western Australian trawl fishery}, volume={9}, number={4}, journal={PLoS One}, author={Allen, S. J. and Tyne, J. A. and Kobryn, H. T. and Bejder, L. and Pollock, K. H. and Loneragan, N. R.}, year={2014} }
 @article{couturier_dudgeon_pollock_jaine_bennett_townsend_weeks_richardson_2014, title={Population dynamics of the reef manta ray Manta alfredi in eastern Australia}, volume={33}, ISSN={["1432-0975"]}, DOI={10.1007/s00338-014-1126-5}, abstractNote={The reef manta ray Manta alfredi aggregates at several sites along the east coast of Australia. Photographic identification and mark–recapture methods were used to report on the site affinity, size and structure of this population of M. alfredi. A total of 716 individuals were identified in 1982–2012, including 636 at Lady Elliot Island (LEI), southern Great Barrier Reef. Over 60 % of individuals identified were resighted at least once during the study period. Multiple resightings within and among years imply a high degree of site affinity by individuals to aggregation sites. One individual was sighted 11 times at LEI over a 30-yr period. The sex ratio of this population was significantly biased towards females (1.2:1 female-to-male ratio), and females were more commonly resighted than males. Robust design population models were used to estimate the population size of the winter aggregation at LEI over a 4-yr period. The models estimated up to 456 (95 % CI 399–535) M. alfredi individuals in the population within one winter season and a high annual apparent survival. This study demonstrated that waters around LEI form a key aggregation site for a large portion of the M. alfredi population in east Australian waters.}, number={2}, journal={CORAL REEFS}, author={Couturier, L. I. E. and Dudgeon, C. L. and Pollock, K. H. and Jaine, F. R. A. and Bennett, M. B. and Townsend, K. A. and Weeks, S. J. and Richardson, A. J.}, year={2014}, month={Jun}, pages={329–342} }
 @article{weaver_kwak_pollock_2014, title={Sampling Characteristics and Calibration of Snorkel Counts to Estimate Stream Fish Populations}, volume={34}, ISSN={0275-5947 1548-8675}, url={http://dx.doi.org/10.1080/02755947.2014.951808}, DOI={10.1080/02755947.2014.951808}, abstractNote={Snorkeling is a versatile technique for estimating lotic fish population characteristics; however, few investigators have evaluated its accuracy at population or assemblage levels. We evaluated the accuracy of snorkeling using prepositioned areal electrofishing (PAE) for estimating fish populations in a medium-sized Appalachian Mountain river during fall 2008 and summer 2009. Strip-transect snorkel counts were calibrated with PAE counts in identical locations among macrohabitats, fish species or taxa, and seasons. Mean snorkeling efficiency (i.e., the proportion of individuals counted from the true population) among all taxa and seasons was 14.7% (SE, 2.5%), and the highest efficiencies were for River Chub Nocomis micropogon at 21.1% (SE, 5.9%), Central Stoneroller Campostoma anomalum at 20.3% (SE, 9.6%), and darters (Percidae) at 17.1% (SE, 3.7%), whereas efficiencies were lower for shiners (Notropis spp., Cyprinella spp., Luxilus spp.) at 8.2% (SE, 2.2%) and suckers (Catostomidae) at 6.6% (SE, 3.2%). Macrohabitat type, fish taxon, or sampling season did not significantly explain variance in snorkeling efficiency. Mean snorkeling detection probability (i.e., probability of detecting at least one individual of a taxon) among fish taxa and seasons was 58.4% (SE, 6.1%). We applied the efficiencies from our calibration study to adjust snorkel counts from an intensive snorkeling survey conducted in a nearby reach. Total fish density estimates from strip-transect counts adjusted for snorkeling efficiency were 7,288 fish/ha (SE, 1,564) during summer and 15,805 fish/ha (SE, 4,947) during fall. Precision of fish density estimates is influenced by variation in snorkeling efficiency and sample size and may be increased with additional sampling effort. These results demonstrate the sampling properties and utility of snorkeling to characterize lotic fish assemblages with acceptable efficiency and detection probability, less effort, and no mortality, compared with traditional sampling methods. Received April 29, 2014; accepted July 23, 2014}, number={6}, journal={North American Journal of Fisheries Management}, publisher={Wiley}, author={Weaver, Daniel M. and Kwak, Thomas J. and Pollock, Kenneth H.}, year={2014}, month={Nov}, pages={1159–1166} }
 @article{wen_pollock_nichols_waser_cao_2014, title={Using imputation and mixture model approaches to integrate multi-state capture-recapture models with assignment information}, volume={70}, ISSN={["1541-0420"]}, DOI={10.1111/biom.12155}, abstractNote={In this article, we first extend the superpopulation capture-recapture model to multiple states (locations or populations) for two age groups., Wen et al., (2011; 2013) developed a new approach combining capture-recapture data with population assignment information to estimate the relative contributions of in situ births and immigrants to the growth of a single study population. Here, we first generalize Wen et al., (2011; 2013) approach to a system composed of multiple study populations (multi-state) with two age groups, where an imputation approach is employed to account for the uncertainty inherent in the population assignment information. Then we develop a different, individual-level mixture model approach to integrate the individual-level population assignment information with the capture-recapture data. Our simulation and real data analyses show that the fusion of population assignment information with capture-recapture data allows us to estimate the origination-specific recruitment of new animals to the system and the dispersal process between populations within the system. Compared to a standard capture-recapture model, our new models improve the estimation of demographic parameters, including survival probability, origination-specific entry probability, and especially the probability of movement between populations, yielding higher accuracy and precision.}, number={2}, journal={BIOMETRICS}, author={Wen, Zhi and Pollock, Kenneth H. and Nichols, James D. and Waser, Peter M. and Cao, Weihua}, year={2014}, month={Jun}, pages={323–334} }
 @article{calver_adams_clark_pollock_2013, title={Assessing the safety of collars used to attach predation deterrent devices and ID tags to pet cats}, volume={22}, ISSN={["0962-7286"]}, DOI={10.7120/09627286.22.1.095}, abstractNote={Abstract Collar-worn deterrents reduce predation by cats while collar-mounted ID enhances return of lost animals. A perception that collars are hazardous limits their use. We defined cases as ‘collar incidents’ (cat snagged its collar or caught a paw), ‘collar injuries’ (veterinary treatment needed for a collar incident), and ‘collar deaths’ (cat died), before integrating data from veterinarians, owners from the general public and owners from a welfare society. Despite biases associated with each of these groups, taken together, the results from these indicated that collar injuries or deaths are rare. Interviews with one hundred and seven veterinarians indicated an average rate of one collar injury observed per 2.3 years of veterinary practice. At one practice, over three years, only 0.33% of 4,460 cat cases were collar injuries, while 180 cat cases at four clinics during August and November 2011 included none. The 63 owners from the general public reported only one collar injury and no deaths in a lifetime of ownership, although 27% experienced collar incidents. In contrast, 22% reported cats needing treatment following road accidents, 53% reported cats needing treatment for fighting injuries and 62% had owned cats killed on the road. Most (62%) of the 55 respondents from a cat welfare society had experienced a collar incident, but only two cats needed treatment. One died. In contrast, 31 and 58% reported cats needing treatment for road accidents and fighting, respectively, and 41% had owned cats killed on the road. Fighting and road accidents are greater hazards to roaming cats than collars, which offer the compensatory benefits of mounting predation deterrents and ID tags.}, number={1}, journal={ANIMAL WELFARE}, author={Calver, M. C. and Adams, G. and Clark, W. and Pollock, K. H.}, year={2013}, month={Feb}, pages={95–105} }
 @article{prescott_vogel_pollock_hyson_oktaviani_panggabean_2013, title={Estimating sea cucumber abundance and exploitation rates using removal methods}, volume={64}, ISSN={1323-1650}, url={http://dx.doi.org/10.1071/MF12081}, DOI={10.1071/MF12081}, abstractNote={Removal methods were used to estimate key fishery parameters, abundance and exploitation rate for five species of tropical sea cucumbers harvested by Indonesian fishers at Scott Reef, north-western Australia. Detailed catch records were kept by the traditional fishers over a period of 58 days as needed for this method, whereas effort was estimated from aerial surveillance. Concurrently, ~1007 artificial sea cucumber surrogates, were distributed and rewards were paid for recovered surrogates. Both datasets were analysed using the Huggins closed-population procedure in program MARK to obtain maximum-likelihood estimates. This procedure allowed inclusion of effort and tide covariates and an initial search phase followed by an exploitation phase. We accounted for extreme over-dispersion which is a common problem in fishery removal data. Our results strongly suggested that some surrogates became unavailable to the fishers. However, results from both datasets demonstrated strong evidence of extreme rates of exploitation on the shallow, drying reef-top habitat. Closed-removal or depletion methods are shown to be a viable method to estimate abundance and exploitation rate for sea cucumbers harvested with intense fishing pressure during a short fishing season.}, number={7}, journal={Marine and Freshwater Research}, publisher={CSIRO Publishing}, author={Prescott, James and Vogel, Camille and Pollock, Kenneth and Hyson, Samuel and Oktaviani, Dian and Panggabean, Anthony Sisco}, year={2013}, pages={599} }
 @inproceedings{hightower_pollock_2013, title={Tagging methods for estimating population size and mortality rates of inland striped bass populations}, volume={80}, booktitle={American Fisheries Society symposium}, author={Hightower, J. and Pollock, K.}, year={2013}, pages={249–262} }
 @article{friedl_buckel_hightower_scharf_pollock_2013, title={Telemetry-Based Mortality Estimates of Juvenile Spot in Two North Carolina Estuarine Creeks}, volume={142}, ISSN={["1548-8659"]}, DOI={10.1080/00028487.2012.730108}, abstractNote={We estimated natural mortality rates (M) of age-1 Spot Leiostomus xanthurus by using a sonic telemetry approach. Sonic transmitters were surgically implanted into a total of 123 age-1 Spot in two North Carolina estuarine creeks during spring 2009 and 2010, and the fish were monitored by using a stationary acoustic receiver array and manual tracking. Fates of telemetered Spot were inferred based on telemetry information from estimated locations and swimming speeds. Potential competitors of age-1 Spot were assessed through simultaneous otter trawl sampling, while potential predators of Spot were collected using gill nets and trammel nets. The number of inferred natural mortalities was zero in 2009 (based on 29 telemetered Spot at risk) and four in 2010 (based on 52 fish at risk), with fish being at risk for up to about 70 d each year. Catches of potential competitors or predators did not differ between years, and age-1 Spot were not found in analyzed stomach contents of potential predators. Our estimated 30-d M of 0.03 (95% credible interval = 0.01–0.07) was lower than that predicted from weight-based (M = 0.07) and life-history-based (M = 0.06–0.36) estimates. Our field-based estimate of M for age-1 Spot in this estuarine system can assist in the assessment and management of Spot by allowing a direct comparison with M-values predicted from fish size or life history characteristics. The field telemetry and statistical analysis techniques developed here provide guidance for future telemetry studies of relatively small fish in open, dynamic habitat systems, as they highlight strengths and weaknesses of using a telemetry approach to estimate M.}, number={2}, journal={TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY}, author={Friedl, Sarah E. and Buckel, Jeffrey A. and Hightower, Joseph E. and Scharf, Fred S. and Pollock, Kenneth H.}, year={2013}, month={Mar}, pages={399–415} }
 @article{smith_pollock_waples_bradley_bejder_2013, title={Use of the robust design to estimate seasonal abundance and demographic parameters of a coastal bottlenose dolphin (Tursiops aduncus) population}, volume={8}, number={10}, journal={PLoS One}, author={Smith, H. C. and Pollock, K. and Waples, K. and Bradley, S. and Bejder, L.}, year={2013} }
 @article{nicholson_bejder_allen_krützen_pollock_2012, title={Abundance, survival and temporary emigration of bottlenose dolphins (Tursiops sp.) off Useless Loop in the western gulf of Shark Bay, Western Australia}, volume={63}, ISSN={1323-1650}, url={http://dx.doi.org/10.1071/MF12210}, DOI={10.1071/MF12210}, abstractNote={Capture–recapture models were used to provide estimates of abundance, apparent survival and temporary emigration of Indo-Pacific bottlenose dolphins (Tursiops sp.) in a 226-km2 study area off Useless Loop in the western gulf of Shark Bay, Western Australia. Photo-identification data were collected during boat-based surveys in Austral autumn to early spring (April–September) from 2007 to 2011. Abundance estimates varied from 115 (s.e. 5.2, 95% CI 105–126) individuals in 2008 to 208 (s.e. 17.3, 95% CI 177–245) individuals in 2010. The variability in abundance estimates is likely to be a reflection of how individuals used the study area, rather than fluctuations in true population size. The best fitting capture–recapture model suggested a random temporary emigration pattern and, when coupled with relatively high temporary emigration rates (0.33 (s.e. 0.07) – 0.66 (s.e. 0.05)) indicated that the study area did not cover the entire ranges of the photo-identified dolphins. Apparent survival rate is a product of true survival and permanent emigration and was estimated annually at 0.95 (s.e. 0.02). Since permanent emigration from the study area is unlikely, true survival was estimated to be close to 0.95. This study provides a robust baseline for future comparisons of dolphin demographics, which may be of importance should climate change or increasing anthropogenic activity affect this population.}, number={11}, journal={Marine and Freshwater Research}, publisher={CSIRO Publishing}, author={Nicholson, Krista and Bejder, Lars and Allen, Simon J. and Krützen, Michael and Pollock, Kenneth H.}, year={2012}, pages={1059} }
 @inbook{pine_hightower_coggins_lauretta_pollock_2012, title={Design and analysis of tagging studies}, ISBN={9781934874295}, booktitle={Fisheries techniques (3rd ed.)}, publisher={Bethesda, Md.: American Fisheries Society}, author={Pine, W. and Hightower, J. and Coggins, L. and Lauretta, M. and Pollock, K.}, editor={A. V. Zale, D. L. Parrish and Sutton, T. M.Editors}, year={2012}, pages={521–572} }
 @article{cooch_conn_ellner_dobson_pollock_2012, title={Disease dynamics in wild populations: modeling and estimation: a review}, volume={152}, ISSN={2193-7192 1439-0361}, url={http://dx.doi.org/10.1007/S10336-010-0636-3}, DOI={10.1007/S10336-010-0636-3}, number={S2}, journal={Journal of Ornithology}, publisher={Springer Science and Business Media LLC}, author={Cooch, Evan G. and Conn, Paul B. and Ellner, Stephen P. and Dobson, Andrew P. and Pollock, Kenneth H.}, year={2012}, pages={485–509} }
 @inproceedings{cooch_conn_ellner_dobson_pollock_2012, title={Disease dynamics in wild populations: modeling and estimation: a review}, volume={152}, booktitle={Journal of Ornithology}, author={Cooch, E. G. and Conn, P. B. and Ellner, S. P. and Dobson, A. P. and Pollock, K. H.}, year={2012}, pages={S485–509} }
 @article{smallwood_pollock_wise_hall_gaughan_2012, title={Expanding Aerial-Roving Surveys to Include Counts of Shore-Based Recreational Fishers from Remotely Operated Cameras: Benefits, Limitations, and Cost Effectiveness}, volume={32}, ISSN={["0275-5947"]}, DOI={10.1080/02755947.2012.728181}, abstractNote={Information on shore-based recreational fishing is essential for the sustainable management of nearshore fish stocks. However, obtaining estimates of catch and effort from such fishing activity can be complex and expensive due to the large spatial scales over which surveys are typically conducted and the fine-scale temporal resolution that is desired. Complementary surveys are one option for improving the accuracy of estimates. A pilot study was conducted in Perth, Western Australia, from April to June 2010 to test an expanded aerial–roving survey design that incorporated remotely operated cameras. Cameras recorded the distribution of shore-based fishing activity across a 24-h day, highlighting an afternoon peak as well as some nighttime activity, which is rarely captured in existing survey designs. This information was combined with instantaneous counts of shore fishers from aerial surveys and trip length data that were obtained from 1,194 incomplete trip interviews conducted during roving creel surveys; the resulting estimate of fishing effort was 213,460 angler-hours (SE = 18,141; relative SE [RSE] = 8%). Catch rates, which were calculated from roving creel survey data on the numbers of retained fish, were combined with fishing effort to estimate a total retained catch of 355,801 fish (SE = 41,446; RSE = 12%). The Australian herring Arripis georgianus was the dominant species, with a retained catch of 229,779 fish (SE = 39,007; RSE = 17%). In comparison with other on-site techniques, the incorporation of cameras into an aerial–roving survey design provides a generic, cost-effective method for measuring the distribution of shore-based fishing activity across a 24-h day. Our findings improve the understanding of the exploitation of nearshore fish stocks along the Perth coast. Our method has broad application to many other recreational fisheries around the world, especially where nighttime fishing is popular. Received June 28, 2012; accepted August 24, 2012}, number={6}, journal={NORTH AMERICAN JOURNAL OF FISHERIES MANAGEMENT}, author={Smallwood, C. B. and Pollock, K. H. and Wise, B. S. and Hall, N. G. and Gaughan, D. J.}, year={2012}, month={Dec}, pages={1265–1276} }
 @article{smith_then_wor_ralph_pollock_hoenig_2012, title={Recommendations for Catch-Curve Analysis}, volume={32}, ISSN={["1548-8675"]}, DOI={10.1080/02755947.2012.711270}, abstractNote={Three common cross-sectional catch-curve methods for estimating total mortality rate (Z) are the Chapman–Robson, regression, and Heincke estimators. There are five unresolved methodological issues: (1) which is the best estimator, (2) how one should determine the first age-group to use in the analysis, (3) how the variance estimators perform; and, for regression estimators, (4) how the observations should be weighted, including (5) whether and how the oldest ages should be truncated. We used analytical methods and Monte Carlo simulation to evaluate the three catch-curve methods, including unweighted and weighted versions of the regression estimator. We evaluated four criteria for specifying the first age-class used. Regression estimators were evaluated with four different methods of right data truncation. Heincke's method performed poorly and is generally not recommended. The two-tailed χ2 test and one-tailed z-test for full selectivity described by Chapman and Robson did not perform as well as simpler criteria and are not recommended. Estimates with the lowest mean square error were generally provided by (1) the Chapman–Robson estimator with the age of full recruitment being the age of maximum catch plus 1 year and (2) the weighted regression estimator with the age of full recruitment being the age of maximum catch and with no right truncation. Differences in performance between the two methods were small (<6% of Z). The Chapman–Robson estimator of the variance of had large negative bias when not corrected for overdispersion; once corrected, it performed as well as or better than all other variance estimators evaluated. The regression variance estimator is generally precise and slightly negatively biased. We recommend that the traditional Chapman–Robson approach be corrected for overdispersion and used routinely to estimate Z. Weighted linear regression may work slightly better but is completely ad hoc. Unweighted linear regression should no longer be used for analyzing catch-curve data. Received November 30, 2011; accepted July 4, 2012}, number={5}, journal={NORTH AMERICAN JOURNAL OF FISHERIES MANAGEMENT}, author={Smith, Matthew W. and Then, Amy Y. and Wor, Catarina and Ralph, Gina and Pollock, Kenneth H. and Hoenig, John M.}, year={2012}, pages={956–967} }
 @article{cannell_pollock_bradley_wooller_sherwin_sinclair_2011, title={Augmenting mark–recapture with beach counts to estimate the abundance of little penguins on Penguin Island, Western Australia}, volume={38}, ISSN={1035-3712}, url={http://dx.doi.org/10.1071/WR11042}, DOI={10.1071/WR11042}, abstractNote={Context Penguin Island supports the largest colony of little penguins in Western Australia. It is subjected to a suite of anthropogenic threats because of its proximity to an increasing urban population. For effective management of the colony, it is necessary to not only have knowledge of the size of the colony, but also the population trend of the colony. Aims To demonstrate a new cost-effective method of estimating the island-wide population of penguins on Penguin Island. Methods We estimated the island-wide population by combining mark–recapture sampling over 2 years on part of the island and beach counts of penguins arriving at night around the entire island. We estimated the abundance using closed population models, allowing for sex and time effects in capture probabilities. We had four capture occasions in 2008 only, and so considered heterogeneity of capture probabilities (Mh), using the Chao heterogeneity moment estimator. The proportion of all penguins counted that arrived at the four mark–recapture sites was then used to inflate the population estimate for the whole island. Key results In all, 62% of all penguins counted used the four mark–recapture sites. In 2007, there were an estimated 2369 ± 198 penguins, and 1543 ± 82 in 2008. When capture heterogeneity was allowed for in 2008, this estimate increased to 2069 ± 172. Conclusions Fewer eggs were laid and all measures of breeding performance were lower in 2008 than in 2007. Hence, the lower population estimate is most likely to represent fewer birds attempting to breed. However, further work on population estimates is required to determine whether capture heterogeneity occurs in both good and poor breeding years. Capture rates were affected by the presence of a full moon and high tides. Implications The estimate of the population can be used as part of the basis of a long-term monitoring program needed for effective management of the penguin colony. However, such studies must be coincident with the monitoring of a suite of reproductive and foraging parameters if short-term impacts of threats are to be recognised and well managed.}, number={6}, journal={Wildlife Research}, publisher={CSIRO Publishing}, author={Cannell, Belinda and Pollock, Ken and Bradley, Stuart and Wooller, Ron and Sherwin, William and Sinclair, Jennifer}, year={2011}, pages={491} }
 @article{turner_rockhill_deperno_jenks_klaver_jarding_grovenburg_pollock_2011, title={Evaluating the Effect of Predators on White-Tailed Deer: Movement and Diet of Coyotes}, volume={75}, ISSN={["0022-541X"]}, DOI={10.1002/jwmg.109}, abstractNote={Coyotes (Canis latrans) may affect adult and neonate white-tailed deer (Odocoileus virginianus) survival and have been implicated as a contributor to the decline of deer populations. Additionally, coyote diet composition is influenced by prey availability, season, and region. Because coyote movement and diet vary by region, local data are important to understand coyote population dynamics and their impact on prey species. In southeast Minnesota, we investigated the effect of coyotes on white-tailed deer populations by doc- umenting movement rates, distances moved, and habitats searched by coyotes during fawning and non- fawning periods. Additionally, we determined survival, cause-specific mortality, and seasonal diet composition of coyotes. From 2001 to 2003, we captured and radiocollared 30 coyotes. Per-hour rate of movement averaged 0.87 km and was greater (P ¼ 0.046) during the fawning (1.07 km) than the non- fawning period (0.80 km); areas searched were similar (P ¼ 0.175) between seasons. Coyote habitat use differed during both seasons; habitats were not used in proportion to their availability (P < 0.001). Croplands were used more (P < 0.001) than their proportional availability during both seasons. Use of grasslands was greater during the fawning period (P ¼ 0.030), whereas use of cropland was greater in the nonfawning period (P < 0.001). We collected 66 fecal samples during the nonfawning period; coyote diets were primarily composed of Microtus spp. (65.2%), and consumption of deer was 9.1%. During the study, 19 coyotes died; annual survival rate range was 0.33-0.41, which was low compared with other studies. Consumption of deer was low and coyotes searched open areas (i.e., cropland) more than fawning areas with dense cover. These factors in addition to high coyote mortality suggested that coyote predation was not likely limiting white-tailed deer populations in southeast Minnesota. 2011 The Wildlife Society.}, number={4}, journal={JOURNAL OF WILDLIFE MANAGEMENT}, author={Turner, Melissa M. and Rockhill, Aimee P. and Deperno, Christopher S. and Jenks, Jonathan A. and Klaver, Robert W. and Jarding, Angela R. and Grovenburg, Troy W. and Pollock, Kenneth H.}, year={2011}, month={May}, pages={905–912} }
 @article{yoshizaki_brownie_pollock_link_2011, title={Modeling misidentification errors that result from use of genetic tags in capture-recapture studies}, volume={18}, ISSN={["1573-3009"]}, DOI={10.1007/s10651-009-0116-1}, number={1}, journal={ENVIRONMENTAL AND ECOLOGICAL STATISTICS}, author={Yoshizaki, Jun and Brownie, Cavell and Pollock, Kenneth H. and Link, William A.}, year={2011}, month={Mar}, pages={27–55} }
 @article{beatty_de graaf_molony_nguyen_pollock_2011, title={Plasticity in population biology of Cherax cainii (Decapoda: Parastacidae) inhabiting lentic and lotic environments in south-western Australia: Implications for the sustainable management of the recreational fishery}, volume={110}, ISSN={0165-7836}, url={http://dx.doi.org/10.1016/j.fishres.2011.04.021}, DOI={10.1016/j.fishres.2011.04.021}, abstractNote={The Smooth Marron Cherax cainii is endemic to south-western Australia and supports an iconic recreational fishery that exploits stocks in both lentic and lotic systems. This study is the first to determine and compare the population biology of a parastacid from both lentic and lotic systems and aimed to gather the information necessary for more effective management of the fishery. Modal progression demonstrated growth rates of juvenile C. cainii were greater in the lentic (Wellington Dam) compared to the lotic (Warren River) system, however, mark-recapture suggested the growth rate of the adult component of the lentic population was stunted whereas in the lotic population 60-90. mm OCL individuals were common and had a faster growth rate. The Wellington Dam stock appeared to be over-exploited and had very low productivity whereas the Warren River stock had relatively low fishing exploitation and a high productivity resulting from higher growth rates coupled with higher population densities (with the trappable population sizes estimated using the open POPAN formulation in the MARK software program). Comparisons of these biological parameters were made with populations elsewhere and there existed a considerable plasticity that is probably due to differences in thermal regimes, degree of habitat complexity, food resource availability and fisher accessibility. The findings demonstrate the need to determine the level of intraspecific biological plasticity in freshwater crayfish in order to sustainably manage their fisheries.}, number={2}, journal={Fisheries Research}, publisher={Elsevier BV}, author={Beatty, Stephen and de Graaf, Martin and Molony, Brett and Nguyen, Vinh and Pollock, Kenneth}, year={2011}, month={Jul}, pages={312–324} }
 @article{riddle_pollock_simons_2010, title={AN UNRECONCILED DOUBLE-OBSERVER METHOD FOR ESTIMATING DETECTION PROBABILITY AND ABUNDANCE}, volume={127}, ISSN={["1938-4254"]}, DOI={10.1525/auk.2010.09118}, abstractNote={Multiple-observer point-count methods allow estimation of detection probability and have some advantages over other point-count methods. We introduce the unreconciled double-observer method, an independent double-observer method that does not require observers to match or otherwise reconcile individual observations. The modeling of the counts uses the repeated-counts model (Royle 2004). We compared estimates of detection probability and abundance from the unreconciled double-observer method with estimates from the traditional independent double-observer method (which requires matching of individual animals) using field-simulated bird-point-count data. The unreconciled double-observer method provided point estimates of detection probability and abundance that were essentially identical to the results of the independent double-observer method, even though much less effort was required to collect data with the unreconciled method. Estimates of detection probability from the unreconciled double-observer method were usually less precise—and estimates of abundance always less precise—than those from the independent double-observer method, because there is less information available in the unreconciled double-observer approach. We also evaluated the unreconciled double-observer method on 12 Breeding Bird Survey (BBS) routes. The unreconciled double-observer method provided estimates of route-level abundance for most routes and for most of the 20 species we considered. We believe that this method has potential for established bird-monitoring programs such as the BBS because no changes in historical data-collection methods are required other than collecting data simultaneously using two or more observers.}, number={4}, journal={AUK}, author={Riddle, Jason D. and Pollock, Kenneth H. and Simons, Theodore R.}, year={2010}, month={Oct}, pages={841–849} }
 @article{tarr_simons_pollock_2010, title={An Experimental Assessment of Vehicle Disturbance Effects on Migratory Shorebirds}, volume={74}, ISSN={["0022-541X"]}, DOI={10.2193/2009-105}, abstractNote={Off-road vehicle (ORV) traffic is one of several forms of disturbance thought to affect shorebirds at migration stopover sites. Attempts to measure disturbance effects on shorebird habitat use and behavior at stopover sites are difficult because ORV disturbance is frequently confounded with habitat and environmental factors. We used a before-after-control-impact experimental design to isolate effects of vehicle disturbance from shorebird responses to environmental and habitat factors. We manipulated disturbance levels within beach closures along South Core Banks, North Carolina, USA, and measured changes in shorebird abundance and location, as well as the activity of one focal species, the sanderling (Calidris alba), within paired control and impact plots. We applied a discrete treatment level of one flee-response-inducing event every 10 minutes on impact plots. We found that disturbance reduced total shorebird and black-bellied plover (Pluvialis squatarola) abundance and reduced relative use of microhabitat zones above the swash zone (wet sand and dry sand) by sanderlings, black-bellied plovers, willets (Tringa semipalmata), and total shorebirds. Sanderlings and total shorebirds increased use of the swash zone in response to vehicle disturbance. Disturbance reduced use of study plots by sanderlings for resting and increased sanderling activity, but we did not detect an effect of vehicle disturbance on sanderling foraging activity. We provide the first estimates of how a discrete level of disturbance affects shorebird distributions among ocean beach microhabitats. Our findings provide a standard to which managers can compare frequency and intensity of disturbance events at other shorebird stopover and roosting sites and indicate that limiting disturbance will contribute to use of a site by migratory shorebirds.}, number={8}, journal={JOURNAL OF WILDLIFE MANAGEMENT}, author={Tarr, Nathan M. and Simons, Theodore R. and Pollock, Kenneth H.}, year={2010}, month={Nov}, pages={1776–1783} }
 @article{mcclintock_bailey_pollock_simons_2010, title={Experimental Investigation of Observation Error in Anuran Call Surveys}, volume={74}, ISSN={["1937-2817"]}, DOI={10.2193/2009-321}, abstractNote={Occupancy models that account for imperfect detection are often used to monitor anuran and songbird species occurrence. However, presence–absence data arising from auditory detections may be more prone to observation error (e.g., false-positive detections) than are sampling approaches utilizing physical captures or sightings of individuals. We conducted realistic, replicated field experiments using a remote broadcasting system to simulate simple anuran call surveys and to investigate potential factors affecting observation error in these studies. Distance, time, ambient noise, and observer abilities were the most important factors explaining false-negative detections. Distance and observer ability were the best overall predictors of false-positive errors, but ambient noise and competing species also affected error rates for some species. False-positive errors made up 5% of all positive detections, with individual observers exhibiting false-positive rates between 0.5% and 14%. Previous research suggests false-positive errors of these magnitudes would induce substantial positive biases in standard estimators of species occurrence, and we recommend practices to mitigate for false positives when developing occupancy monitoring protocols that rely on auditory detections. These recommendations include additional observer training, limiting the number of target species, and establishing distance and ambient noise thresholds during surveys.}, number={8}, journal={JOURNAL OF WILDLIFE MANAGEMENT}, author={Mcclintock, Brett T. and Bailey, Larissa L. and Pollock, Kenneth H. and Simons, Theodore R.}, year={2010}, month={Nov}, pages={1882–1893} }
 @article{pledger_pollock_norris_2010, title={Open Capture-Recapture Models with Heterogeneity: II. Jolly-Seber Model}, volume={66}, ISSN={["1541-0420"]}, DOI={10.1111/j.1541-0420.2009.01361.x}, abstractNote={Summary Estimation of abundance is important in both open and closed population capture–recapture analysis, but unmodeled heterogeneity of capture probability leads to negative bias in abundance estimates. This article defines and develops a suite of open population capture–recapture models using finite mixtures to model heterogeneity of capture and survival probabilities. Model comparisons and parameter estimation use likelihood-based methods. A real example is analyzed, and simulations are used to check the main features of the heterogeneous models, especially the quality of estimation of abundance, survival, recruitment, and turnover. The two major advances in this article are the provision of realistic abundance estimates that take account of heterogenetiy of capture, and an appraisal of the amount of overestimation of survival arising from conditioning on the first capture when heterogeneity of survival is present.}, number={3}, journal={BIOMETRICS}, author={Pledger, Shirley and Pollock, Kenneth H. and Norris, James L.}, year={2010}, month={Sep}, pages={883–890} }
 @article{riddle_stanislav_pollock_moorman_perkins_2010, title={Separating Components of the Detection Process With Combined Methods: An Example With Northern Bobwhite}, volume={74}, ISSN={["1937-2817"]}, DOI={10.2193/2009-220}, abstractNote={There are various methods of estimating detection probabilities for avian point counts. Distance and multiple-observer methods require the sometimes unlikely assumption that all birds in the population are available (i.e., sing or are visible) during a count, but the time-of-detection method allows for the possibility that some birds are unavailable during the count. We combined the dependent double-observer method with the time-of-detection method and obtained field-based estimates of the components of detection probability for northern bobwhite (Colinus virginianus). Our approach was a special case of Pollock's robust capture–recapture design where the probability that a bird does not sing is analogous to the probability that an animal is a temporary emigrant. Top models indicated that observers' detection probabilities were similar (0.78–0.84) if bobwhite were available, but bobwhite only had an approximately 0.61 probability of being available during a 2.5-minute sampling interval. Additionally, observers' detection probabilities increased substantially after the initial encounter with an individual bobwhite (analogous to a trap-happy response on the part of the observer). A simulated data set revealed that the combined method was precise when availability and detection given availability were substantially lower. Combined methods approaches can provide critical information for researchers and land managers to make decisions regarding survey length and personnel requirements for point-count–based surveys.}, number={6}, journal={JOURNAL OF WILDLIFE MANAGEMENT}, author={Riddle, Jason D. and Stanislav, Stephen J. and Pollock, Kenneth H. and Moorman, Christopher E. and Perkins, Fern S.}, year={2010}, month={Aug}, pages={1319–1325} }
 @article{link_yoshizaki_bailey_pollock_2010, title={Uncovering a latent multinomial: Analysis of mark-recapture data with misidentification}, volume={66}, DOI={10.1111/j.1541-0420.2009.01244.x}, abstractNote={Natural tags based on DNA fingerprints or natural features of animals are now becoming very widely used in wildlife population biology. However, classic capture-recapture models do not allow for misidentification of animals which is a potentially very serious problem with natural tags. Statistical analysis of misidentification processes is extremely difficult using traditional likelihood methods but is easily handled using Bayesian methods. We present a general framework for Bayesian analysis of categorical data arising from a latent multinomial distribution. Although our work is motivated by a specific model for misidentification in closed population capture-recapture analyses, with crucial assumptions which may not always be appropriate, the methods we develop extend naturally to a variety of other models with similar structure. Suppose that observed frequencies f are a known linear transformation f=A'x of a latent multinomial variable x with cell probability vector pi=pi(theta). Given that full conditional distributions [theta | x] can be sampled, implementation of Gibbs sampling requires only that we can sample from the full conditional distribution [x | f, theta], which is made possible by knowledge of the null space of A'. We illustrate the approach using two data sets with individual misidentification, one simulated, the other summarizing recapture data for salamanders based on natural marks.}, number={1}, journal={Biometrics}, author={Link, W. A. and Yoshizaki, J. and Bailey, L. L. and Pollock, K. H.}, year={2010}, pages={178–185} }
 @article{mcclintock_bailey_pollock_simons_2010, title={Unmodeled observation error induces bias when inferring patterns and dynamics of species occurrence via aural detections}, volume={91}, ISSN={["0012-9658"]}, DOI={10.1890/09-1287.1}, abstractNote={The recent surge in the development and application of species occurrence models has been associated with an acknowledgment among ecologists that species are detected imperfectly due to observation error. Standard models now allow unbiased estimation of occupancy probability when false negative detections occur, but this is conditional on no false positive detections and sufficient incorporation of explanatory variables for the false negative detection process. These assumptions are likely reasonable in many circumstances, but there is mounting evidence that false positive errors and detection probability heterogeneity may be much more prevalent in studies relying on auditory cues for species detection (e.g., songbird or calling amphibian surveys). We used field survey data from a simulated calling anuran system of known occupancy state to investigate the biases induced by these errors in dynamic models of species occurrence. Despite the participation of expert observers in simplified field conditions, both false positive errors and site detection probability heterogeneity were extensive for most species in the survey. We found that even low levels of false positive errors, constituting as little as 1% of all detections, can cause severe overestimation of site occupancy, colonization, and local extinction probabilities. Further, unmodeled detection probability heterogeneity induced substantial underestimation of occupancy and overestimation of colonization and local extinction probabilities. Completely spurious relationships between species occurrence and explanatory variables were also found. Such misleading inferences would likely have deleterious implications for conservation and management programs. We contend that all forms of observation error, including false positive errors and heterogeneous detection probabilities, must be incorporated into the estimation framework to facilitate reliable inferences about occupancy and its associated vital rate parameters.}, number={8}, journal={ECOLOGY}, author={McClintock, Brett T. and Bailey, Larissa L. and Pollock, Kenneth H. and Simons, Theodore R.}, year={2010}, month={Aug}, pages={2446–2454} }
 @article{bacheler_hightower_burdick_paramore_buckel_pollock_2010, title={Using generalized linear models to estimate selectivity from short-term recoveries of tagged red drum Sciaenops ocellatus: Effects of gear, fate, and regulation period}, volume={102}, ISSN={["1872-6763"]}, DOI={10.1016/j.fishres.2009.12.007}, abstractNote={Estimating the selectivity patterns of various fishing gears is a critical component of fisheries stock assessment due to the difficulty in obtaining representative samples from most gears. We used short-term recoveries (n = 3587) of tagged red drum Sciaenops ocellatus to directly estimate age- and length-based selectivity patterns using generalized linear models. The most parsimonious models were selected using AIC, and standard deviations were estimated using simulations. Selectivity of red drum was dependent upon the regulation period in which the fish was caught, the gear used to catch the fish (i.e., hook-and-line, gill nets, pound nets), and the fate of the fish upon recovery (i.e., harvested or released); models including all first-order interactions between main effects outperformed models without interactions. Selectivity of harvested fish was generally dome-shaped and shifted toward larger, older fish in response to regulation changes. Selectivity of caught-and-released red drum was highest on the youngest and smallest fish in the early and middle regulation periods, but increased on larger, legal-sized fish in the late regulation period. These results suggest that catch-and-release mortality has consistently been high for small, young red drum, but has recently become more common in larger, older fish. This method of estimating selectivity from short-term tag recoveries is valuable because it is simpler than full tag-return models, and may be more robust because yearly fishing and natural mortality rates do not need to be modeled and estimated.}, number={3}, journal={FISHERIES RESEARCH}, author={Bacheler, Nathan M. and Hightower, Joseph E. and Burdick, Summer M. and Paramore, Lee M. and Buckel, Jeffrey A. and Pollock, Kenneth H.}, year={2010}, month={Mar}, pages={266–275} }
 @article{yoshizaki_pollock_brownie_webster_2009, title={Modeling misidentification errors in capture-recapture studies using photographic identification of evolving marks}, volume={90}, ISSN={["1939-9170"]}, DOI={10.1890/08-0304.1}, abstractNote={Misidentification of animals is potentially important when naturally existing features (natural tags) are used to identify individual animals in a capture-recapture study. Photographic identification (photoID) typically uses photographic images of animals' naturally existing features as tags (photographic tags) and is subject to two main causes of identification errors: those related to quality of photographs (non-evolving natural tags) and those related to changes in natural marks (evolving natural tags). The conventional methods for analysis of capture-recapture data do not account for identification errors, and to do so requires a detailed understanding of the misidentification mechanism. Focusing on the situation where errors are due to evolving natural tags, we propose a misidentification mechanism and outline a framework for modeling the effect of misidentification in closed population studies. We introduce methods for estimating population size based on this model. Using a simulation study, we show that conventional estimators can seriously overestimate population size when errors due to misidentification are ignored, and that, in comparison, our new estimators have better properties except in cases with low capture probabilities (< 0.2) or low misidentification rates (< 2.5%).}, number={1}, journal={ECOLOGY}, author={Yoshizaki, Jun and Pollock, Kenneth H. and Brownie, Cavell and Webster, Raymond A.}, year={2009}, month={Jan}, pages={3–9} }
 @article{riddle_moorman_pollock_2008, title={A comparison of methods for estimating northern bobwhite covey detection probabilities}, volume={72}, DOI={10.2193/2007-435}, abstractNote={We compared the time-of-detection and logistic regression methods of estimating probability of detection for northern bobwhite (Colinus virginianus) coveys. Both methods are unusual in that they allow estimation of the total probability of detection (i.e., the product of the probability that a covey is available for detection [i.e., that a covey vocalizes] and detection given availability). The logistic regression method produced an average detection probability of 0.596 (SE = 0.020) and the time-of-detection method produced a detection probability estimate of 0.540 (SE = 0.086), and the 2 estimates were not significantly different. This is the first evaluation of the time-of-detection method with empirical field data. Although the time-of-detection and logistic regression method each have advantages, both can be used under appropriate conditions to improve estimates of bobwhite abundance by allowing for the estimation of detection probabilities. Improved estimates of bobwhite abundance will allow land managers to make more informed management decisions.}, number={6}, journal={Journal of Wildlife Management}, author={Riddle, J. D. and Moorman, C. E. and Pollock, K. H.}, year={2008}, pages={1437–1442} }
 @article{alldredge_pacifici_simons_pollock_2008, title={A novel field evaluation of the effectiveness of distance and independent observer sampling to estimate aural avian detection probabilities}, volume={45}, ISSN={0021-8901 1365-2664}, url={http://dx.doi.org/10.1111/j.1365-2664.2008.01517.x}, DOI={10.1111/j.1365-2664.2008.01517.x}, abstractNote={1 The validation of field sampling techniques is a concern for applied ecologists due to the strong model assumptions implicit in all methods. Computer simulations make replication easy, but they do not give insights into how much bias occurs in real populations. Testing sampling methods on populations of known size can establish directly how well estimators perform, but such populations are very hard to find, and replicate, and they may have unusual attributes. 2 We present a field validation of distance and double-observer methods of estimating detection probabilities on aural avian point counts. Our research is relevant to conservation agencies worldwide who design thousands of avian monitoring programmes based primarily on auditory point counts. The programmes are a critical component in the management of many avian species. 3 Our validation used a simulation system which mimics birds calling in a field environment. The system allowed us to vary singing rate, species, distance, the complexity of points, and other factors. 4 Distance methods performed poorly, primarily due to large localization errors, and estimates did not improve for simplified points. 5 For the double-observer method, two pairs of observers tended to underestimate true population size, while the third pair tended to double-count birds which overestimated the population. Detection probabilities were always higher and population estimates lower when observers subjectively matched birds compared to an objective rule and showed a slight negative bias and good precision. A simplified 45-degree matching rule did not improve the performance of double-observer estimates which had a slight positive bias and much lower precision. Double-observer estimates did improve on the simplified points. 6 Synthesis and applications. We encourage ecologists working with sampling methods to develop similar methods of working with simulated populations through use of technology. Our simulated field evaluation has demonstrated the difficulty of accurately estimating population size when limited to aural detections. Problems are related to limitations in the ability of observers to localize sound, estimate distance, and accurately identify birds during a count. Other sources of error identified are the effects of observers, singing rate, singing orientation and background noise.}, number={5}, journal={Journal of Applied Ecology}, publisher={Wiley}, author={Alldredge, Mathew W. and Pacifici, Krishna and Simons, Theodore R. and Pollock, Kenneth H.}, year={2008}, month={Oct}, pages={1349–1356} }
 @article{bacheler_hightower_paramore_buckel_pollock_2008, title={An Age-Dependent Tag Return Model for Estimating Mortality and Selectivity of an Estuarine-Dependent Fish with High Rates of Catch and Release}, volume={137}, ISSN={["1548-8659"]}, DOI={10.1577/T07-146.1}, abstractNote={Red drum Sciaenops ocellatus support commercial and recreational fisheries in North Carolina, but the stock was overfished in the 1980s because fishing was unregulated. Subsequent fishery regulations increased subadult survival into adult age-classes, but overall stock status is difficult to assess because of migration to ocean waters, prohibited harvest of older fish, and relative importance of catch and release. We analyzed 24 years of tagging data from the North Carolina Division of Marine Fisheries to assess the effects of two regulation changes (effected in 1991 and 1998) on fishing mortality rate (F) and selectivity (SEL) patterns of red drum. We used an age-dependent tag return model that accounted for both harvest and catch-and-release fishing. Using external estimates of natural mortality (M) and annual tag retention rate, we obtained precise estimates of annual F; an overall tag reporting rate (λ); and fate-specific, age-specific, and regulation-period-specific SEL. Estimated F of fully selected red drum was high and variable before 1991 (mean F = 2.38) but decreased in magnitude and variability after 1991. A dome-shaped pattern of SEL was observed for harvested fish in all regulation periods; maximum SEL occurred at age 2, when red drum were of harvestable size and found in more-accessible estuarine waters. Selectivity for caught-and-released red drum generally decreased for younger ages and increased for older ages in later regulation periods. The λ was estimated at 18% and was generally insensitive to changes in the inputs of M or tag retention rate. As catch-and-release fishing increases, tag return models may be important tools for studying fish populations, as long as practical issues, such as λ, tag loss, timing of tagging, and hooking and tagging mortality, are addressed.}, number={5}, journal={TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY}, author={Bacheler, Nathan M. and Hightower, Joseph E. and Paramore, Lee M. and Buckel, Jeffrey A. and Pollock, Kenneth H.}, year={2008}, month={Sep}, pages={1422–1432} }
 @article{webster_pollock_simons_2008, title={Bayesian spatial modeling of data from avian point count surveys}, volume={13}, ISSN={["1537-2693"]}, DOI={10.1198/108571108X311563}, number={2}, journal={JOURNAL OF AGRICULTURAL BIOLOGICAL AND ENVIRONMENTAL STATISTICS}, author={Webster, Raymond A. and Pollock, Kenneth H. and Simons, Theodore R.}, year={2008}, month={Jun}, pages={121–139} }
 @article{wibster_pollock_ghosh_hankin_2008, title={Bayesian spatial modeling of data from unit-count surveys of fish in streams}, volume={137}, ISSN={["1548-8659"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-43449101549&partnerID=MN8TOARS}, DOI={10.1577/T06-138.1}, abstractNote={We describe a framework for spatial modeling of data from surveys of stream-dwelling fish species in which repeated counts are made of animals within a sample of habitat units. Using Bayesian modeling with Markov chain-Monte Carlo (MCMC) algorithms, it is possible to estimate fish population size from repeated-count survey data while allowing fish detection probabilities to vary across the stream. We propose the use of conditional autoregressive models for modeling the spatial dependence of density across the habitat units of the stream. The spatial dependence model can be used along with covariate models for density and detection to predict density at unsampled units and thereby estimate total abundance across the stream. We apply these models to data sampled from an intensive repeated-count survey of juvenile coho salmon Oncorhynchus kisutch in McGarvey Creek, Northern California. Spatial dependence in fish density was detected, and models that account for spatial dependence produced more precise predictions at unsurveyed units, and thus more precise estimates of total stream abundance, than models that assumed spatial independence. Through a small simulation study, we show that ignoring heterogeneity in detection probabilities can lead to significant underestimation of total abundance. Inclusion of heterogeneity by means of a random effect in the detection component of the model can lead to numerical instability of the MCMC method, and we stress the importance of accounting for heterogeneity by incorporating covariates in modeling detection probability.}, number={2}, journal={TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY}, author={Wibster, Raymond A. and Pollock, Kenneth H. and Ghosh, Sujit K. and Hankin, David G.}, year={2008}, month={Mar}, pages={438–453} }
 @article{haddad_hudgens_damiani_gross_kuefler_pollock_2008, title={Determining optimal population monitoring for rare butterflies}, volume={22}, ISSN={["1523-1739"]}, DOI={10.1111/j.1523-1739.2008.00932.x}, abstractNote={Determining population viability of rare insects depends on precise, unbiased estimates of population size and other demographic parameters. We used data on the endangered St. Francis' satyr butterfly (Neonympha mitchellii francisci) to evaluate 2 approaches (mark-recapture and transect counts) for population analysis of rare butterflies. Mark-recapture analysis provided by far the greatest amount of demographic information, including estimates (and standard errors) of population size, detection, survival, and recruitment probabilities. Mark-recapture analysis can also be used to estimate dispersal and temporal variation in rates, although we did not do this here. Models of seasonal flight phenologies derived from transect counts (Insect Count Analyzer) provided an index of population size and estimates of survival and statistical uncertainty. Pollard-Yates population indices derived from transect counts did not provide estimates of demographic parameters. This index may be highly biased if detection and survival probabilities vary spatially and temporally. In terms of statistical performance, mark-recapture and Pollard-Yates indices were least variable. Mark-recapture estimates were less likely to fail than Insect Count Analyzer, but mark-recapture estimates became less precise as sampling intensity decreased. In general, count-based approaches are less costly and less likely to cause harm to rare insects than mark-recapture. The optimal monitoring approach must reconcile these trade-offs. Thus, mark-recapture should be favored when demographic estimates are needed, when financial resources enable frequent sampling, and when marking does not harm the insect populations. The optimal sampling strategy may use 2 sampling methods together in 1 overall sampling plan: limited mark-recapture sampling to estimate survival and detection probabilities and frequent but less expensive transect counts.}, number={4}, journal={CONSERVATION BIOLOGY}, author={Haddad, Nick M. and Hudgens, Brian and Damiani, Chris and Gross, Kevin and Kuefler, Daniel and Pollock, Ken}, year={2008}, month={Aug}, pages={929–940} }
 @article{pacifici_simons_pollock_2008, title={EFFECTS OF VEGETATION AND BACKGROUND NOISE ON THE DETECTION PROCESS IN AUDITORY AVIAN POINT-COUNT SURVEYS}, volume={125}, ISSN={0004-8038 1938-4254}, url={http://dx.doi.org/10.1525/auk.2008.07078}, DOI={10.1525/auk.2008.07078}, abstractNote={We used a bird-song simulation system to experimentally assess the effects of habitat, vegetation structure, and background noise on detection probability in aural avian point counts. We simulated bird songs of seven species in two habitats (mixed pine–hardwood forest and deciduous forest) and two leaf conditions (leaves on and leaves off) with two levels of background noise (~40 dB and ~50 dB). Estimated detection probabilities varied greatly among species, and complex interactions among all the factors existed. Background noise and the presence of leaves on trees decreased detection probabilities, and estimated detection probabilities were higher in mixed pine–hardwood forest than in deciduous forest. At 100 m, average estimated detection probabilities ranged from 0 to 1 and were lowest for the Black-and-white Warbler (Mniotilta varia) and highest for the Brown Thrasher (Toxostoma rufum). Simulations of expected counts, based on the best logistic model, indicated that observers detect between 3% (for the worst observer, least detectable species, with leaves on the trees and added background noise in the deciduous forest) and 99% (for the best observer, most detectable species, with no leaves on the trees and no added background noise in the mixed forest) of the total count. The large variation in expected counts illustrates the importance of estimating detection probabilities directly. The large differences in detection probabilities among species suggest that tailoring monitoring protocols to specific species of interest may produce better estimates than a single protocol applied to a wide range of species.}, number={3}, journal={The Auk}, publisher={Oxford University Press (OUP)}, author={Pacifici, Krishna and Simons, Theodore R. and Pollock, Kenneth H.}, year={2008}, month={Jul}, pages={600–607} }
 @article{pacific_simons_pollock_2008, title={EFFECTS OF VEGETATION AND BACKGROUND NOISE ON THE DETECTION PROCESS IN AUDITORY AVIAN POINT-COUNT SURVEYS (vol 125, pg 500, 2008)}, volume={125}, ISSN={["0004-8038"]}, DOI={10.1525/auk.2008.111008}, number={4}, journal={AUK}, author={Pacific, Krishna and Simons, Theodore R. and Pollock, Kenneth H.}, year={2008}, month={Oct}, pages={998–998} }
 @article{polacheck_eveson_laslett_pollock_hearn_2008, title={Erratum: Integrating catch-at-age and multiyear tagging data: a combined Brownie and Petersen estimation approach in a fishery context (vol 63, pg 534, 2006)}, volume={65}, ISSN={["0706-652X"]}, DOI={10.1139/f08-072}, number={6}, journal={CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES}, author={Polacheck, Tom and Eveson, J. Paige and Laslett, Geoff M. and Pollock, Kenneth H. and Hearn, William S.}, year={2008}, month={Jun}, pages={1244–1244} }
 @article{riddle_moorman_pollock_2008, title={The importance of habitat shape and landscape context to northern bobwhite populations}, volume={72}, ISSN={["1937-2817"]}, DOI={10.2193/2007-469}, abstractNote={Northern bobwhite (Colinus virginianus) populations have declined nationally for at least the past 4 decades. Field borders have been promoted as an important component of conservation plans to reverse this decline. Field border characteristics, such as shape and the landscapes in which the borders are established, have the potential to influence their effectiveness for recovering northern bobwhite populations. We established narrow linear (approx. 3-m-wide) and nonlinear field borders on farms in agriculture-dominated and forest-dominated landscapes in the Coastal Plain of North Carolina, USA, after collecting pretreatment data on summer bobwhite abundance. After establishment of field borders, summer bobwhite abundance nearly doubled on farms in agriculture-dominated landscapes and increased approximately 57% on farms with nonlinear field borders. Summer bobwhite abundance did not increase on farms with linear field borders in forest-dominated landscapes. Nonlinear and narrow linear field borders can be used to increase bobwhite numbers on farms in landscapes dominated by agriculture. Less flexibility exists in forest-dominated landscapes, where we found only nonlinear field borders resulted in an increase.}, number={6}, journal={JOURNAL OF WILDLIFE MANAGEMENT}, author={Riddle, Jason D. and Moorman, Christopher E. and Pollock, Kenneth H.}, year={2008}, month={Aug}, pages={1376–1382} }
 @article{deperno_matthews_pollock_woodward_2008, title={Visible implant fluorescent elastomer: A reliable marking alternative for snakes}, volume={39}, number={3}, journal={Herpetological Review}, author={DePerno, C. and Matthews, C. and Pollock, K. and Woodward, D.}, year={2008}, pages={301–303} }
 @article{alldredge_simons_pollock_2007, title={A field evaluation of distance measurement error in auditory avian point count surveys}, volume={71}, ISSN={["1937-2817"]}, DOI={10.2193/2006-161}, abstractNote={Detection distance is an important and common auxiliary variable measured during avian point count surveys. Distance data are used to determine the area sampled and to model the detection process using distance sampling theory. In densely forested habitats, visual detections of birds are rare, and most estimates of detection distance are based on auditory cues. Distance sampling theory assumes detection distances are measured accurately, but empirical validation of this assumption for auditory detections is lacking. We used a song playback system to simulate avian point counts with known distances in a forested habitat to determine the error structure of distance estimates based on auditory detections. We conducted field evaluations with 6 experienced observers both before and after distance estimation training. We conducted additional studies to determine the effect of height and speaker orientation (toward or away from observers) on distance estimation error. Distance estimation errors for all evaluations were substantial, although training reduced errors and bias in distance estimates by approximately 15%. Measurement errors showed a nonlinear relationship to distance. Our results suggest observers were not able to differentiate distances beyond 65 m. The height from which we played songs had no effect on distance estimation errors in this habitat. The orientation of the song source did have a large effect on distance estimation errors; observers generally doubled their distance estimates for songs played away from them compared with distance estimates for songs played directly toward them. These findings, which we based on realistic field conditions, suggest measures of uncertainty in distance estimates to auditory detections are substantially higher than assumed by most researchers. This means aural point count estimates of avian abundance based on distance methods deserve careful scrutiny because they are likely biased.}, number={8}, journal={JOURNAL OF WILDLIFE MANAGEMENT}, author={Alldredge, Mathew W. and Simons, Theodore R. and Pollock, Kenneth H.}, year={2007}, month={Nov}, pages={2759–2766} }
 @article{jiang_pollock_brownie_hightower_hoenig_hearn_2007, title={Age-dependent tag return models for estimating fishing mortality, natural mortality, and selectivity}, volume={12}, ISSN={["1537-2693"]}, DOI={10.1198/108571107x197382}, abstractNote={Tag return studies play an important role in providing estimates of mortality rates needed for management of many fisheries, but current methods of estimation do not allow age dependence of instantaneous mortality rates. We present models that allow age-dependent fishing and natural mortality rates, an important advance, because there is often substantial variation in age (and size) of fish at tagging. Age dependence of fishing mortality is modeled by assuming that availability to the fishery, that is, selectivity, depends on age but is constant over years. We assume that all age classes are tagged each year, and allow for incomplete mixing of newly tagged fish and for fisheries that are year-long or limited to a fishing season. We investigate parameter redundancy and estimator performance using analytic and simulation methods, and show that estimator properties are poor if the tag reporting rate is estimated (without auxiliary data such as planted tags). We analyzed multiple age class tag return data from a 13-year study on striped bass (Morone saxatilis) and saw clear evidence that selectivity increases with age. Assuming that the tag reporting rate is constant and known, results also demonstrate age dependence of natural mortality rates, and an increase in natural mortality rates from about 1999 coinciding with observation of a bacterial disease in the fish.}, number={2}, journal={JOURNAL OF AGRICULTURAL BIOLOGICAL AND ENVIRONMENTAL STATISTICS}, author={Jiang, Honghua and Pollock, Kenneth H. and Brownie, Cavell and Hightower, Joseph E. and Hoenig, John M. and Hearn, William S.}, year={2007}, month={Jun}, pages={177–194} }
 @article{jiang_brownie_hightower_pollock_2007, title={Estimating fishing mortality, natural mortality, and selectivity using recoveries from tagging young fish}, volume={27}, ISSN={["0275-5947"]}, DOI={10.1577/M06-127.1}, abstractNote={Current methods for estimation of age- and year-specific instantaneous mortality rates based on multiyear, multiple-age tagging studies assume that it is feasible to tag fish in a wide range of ages. For some species, however, only the youngest one or two age-classes are readily available for tagging. Given the practical advantages of tagging young fish only, an important question is whether such studies would provide the information needed for estimation of age-dependent mortality rates. We investigated three designs: tagging only the youngest available age-class, tagging the two youngest age-classes, and tagging the first five age-classes. We carried out simulation studies to assess estimator performance under these three designs, in each case assuming the same total number of tagged fish. Data were generated assuming fishing mortality rates to be age and year dependent and natural mortality rates to be constant or with limited age dependence. Estimator performance is best when fish are tagged in five age-classes, and tagging fish in the two youngest age-classes shows substantial improvement compared with tagging one age-class only. External information about the tag-reporting rate is necessary to obtain estimators with reasonable properties, especially in the case of models with age-dependent natural mortality. Such information can be obtained from auxiliary studies by means of high-reward tags or planted tags. Collecting recovery information for several additional years after the last release produces small improvements in precision and bias. If tagging fish in multiple age-classes is impractical, reasonable precision can be obtained by tagging one or preferably two age-classes and obtaining supplemental information on the reporting rate. For illustration, estimates of age-dependent fishing and natural mortality rates were obtained from tag returns on Chesapeake Bay striped bass Morone saxatilis tagged at ages 3 and 4 years.}, number={3}, journal={NORTH AMERICAN JOURNAL OF FISHERIES MANAGEMENT}, author={Jiang, Honghua and Brownie, Cavell and Hightower, Joseph E. and Pollock, Kenneth H.}, year={2007}, month={Aug}, pages={773–781} }
 @article{edwards_pollock_ackerman_reynolds_powell_2007, title={Estimation of detection probability in manatee aerial surveys at a winter aggregation site}, volume={71}, ISSN={["0022-541X"]}, DOI={10.2193/2005-645}, abstractNote={Estimating components of detection probability is crucial to improving the design of aerial surveys for wildlife populations, and this is especially true for species of marine mammals that are threatened or endangered. To evaluate the probability that Florida manatees (Trichechus manatus latirostris) will be detected by observers during aerial surveys, we conducted 6 series of survey flights, during mornings and afternoons on 14–16 consecutive days over the Tampa Electric Company's (TECO) Big Bend power plant discharge canal in Tampa Bay, Florida, USA (winter 2000 through 2003). Our objective was to understand how our ability to detect manatees at a winter aggregation site affects aerial survey counts, so that we may improve techniques for estimating manatee population size. We estimated the probability that manatees would be present at the warm-water discharge of the plant during winter cold fronts and estimated the overall detection probability of manatees present at the plant and the 2 components that make up the probability of detection (the probability of being available and the probability of being detected given they are available). We used telemetry tags and marker flags (n = 15) to facilitate capture–recapture analyses. The probability that marked manatees would be at the plant varied from 48% to 68% across flight series and was inversely related to the ambient water temperature. Based on sightings of marked animals, estimates of the overall probability of detecting a manatee ranged from 45% to 69% across flight series (x̄ = 58%, n = 6). The probability that a manatee would be available to an observer ranged from 73% to 94% across flight series (x̄ = 83%) but was constant among years (83%, 81%, and 78%; x̄ = 81%). The probability that an available manatee would be detected by an aerial observer was variable across flight series (55–95%) and years (73%, 86%, and 66%, x̄ = 73%). Independent estimates of the probability that a manatee would be available to the observer on one pass were obtained from time–depth data loggers and ranged from 5% to 33% (x̄ = 19%, SE = 3.7%), and the probability that a manatee would be available during ≥1 of 10 passes ranged from 41% to 98% (x̄ = 88%, 95% confidence bounds 0.71–0.95). We adjusted survey counts using measures of detectability. Although corrected counts presented here are site-specific, adjusting counts based on detection probability will greatly improve reliability of population estimates from all aerial surveys. Special sampling to estimate components of detection probability should be built into all aerial surveys to ensure that reliable and unbiased information on species abundance is used to evaluate wildlife populations.}, number={6}, journal={JOURNAL OF WILDLIFE MANAGEMENT}, author={Edwards, Holly H. and Pollock, Kenneth H. and Ackerman, Bruce B. and Reynolds, John E., III and Powell, James A.}, year={2007}, month={Aug}, pages={2052–2060} }
 @article{simons_alldredge_pollock_wettroth_2007, title={Experimental analysis of the auditory detection process on avian point counts}, volume={124}, ISSN={["1938-4254"]}, DOI={10.1642/0004-8038(2007)124[986:EAOTAD]2.0.CO;2}, abstractNote={We have developed a system for simulating the conditions of avian surveys in which birds are identified by sound. The system uses a laptop computer to control a set of amplified MP3 players placed at known locations around a survey point. The system can realistically simulate a known population of songbirds under a range of factors that affect detection probabilities. The goals of our research are to describe the sources and range of variability affecting point-count estimates and to find applications of sampling theory and methodologies that produce practical improvements in the quality of bird-census data. Initial experiments in an open field showed that, on average, observers tend to undercount birds on unlimited-radius counts, though the proportion of birds counted by individual observers ranged from 81% to 132% of the actual total. In contrast to the unlimited-radius counts, when data were truncated at a 50-m radius around the point, observers overestimated the total population by 17% to 122%. Results also illustrate how detection distances decline and identification errors increase with increasing levels of ambient noise. Overall, the proportion of birds heard by observers decreased by 28 ± 4.7% under breezy conditions, 41 ± 5.2% with the presence of additional background birds, and 42 ± 3.4% with the addition of 10 dB of white noise. These findings illustrate some of the inherent difficulties in interpreting avian abundance estimates based on auditory detections, and why estimates that do not account for variations in detection probability will not withstand critical scrutiny.}, number={3}, journal={AUK}, author={Simons, Theodore R. and Alldredge, Mathew W. and Pollock, Kenneth H. and Wettroth, John M.}, year={2007}, month={Jul}, pages={986–999} }
 @article{alldredge_simons_pollock_2007, title={Factors affecting aural detections of songbirds}, volume={17}, ISSN={["1939-5582"]}, DOI={10.1890/06-0685}, abstractNote={Many factors affect the number of birds detected on point count surveys of breeding songbirds. The magnitude and importance of these factors are not well understood. We used a bird song simulation system to quantify the effects of detection distance, singing rate, species differences, and observer differences on detection probabilities of birds detected by ear. We simulated 40 point counts consisting of 10 birds per count for five primary species (Black-and-white Warbler Mniotilta varia, Black-throated Blue Warbler Dendroica caerulescens, Black-throated Green Warbler Dendroica virens, Hooded Warbler Wilsonia citrina, and Ovenbird Seiurus aurocapillus) over a range of 15 distances (34–143 m). Songs were played at low (two songs per count) and high (13–21 songs per count) singing rates. Detection probabilities averaged across observers ranged from 0.60 (Black-and-white Warbler) to 0.83 (Hooded Warbler) at the high singing rate and 0.41 (Black-and-white Warbler) to 0.67 (Hooded Warbler) at the low singing rate. Logistic regression analyses indicated that species, singing rate, distance, and observer were all significant factors affecting detection probabilities. Singing rate × species and singing rate × distance interactions were also significant. Simulations of expected counts, based on the best logistic model, indicated that observers detected between 19% (for the worst observer, lowest singing rate, and least detectable species) and 65% (for the best observer, highest singing rate, and most detectable species) of the true population. Detection probabilities on actual point count surveys are likely to vary even more because many sources of variability were controlled in our experiments. These findings strongly support the importance of adjusting measures of avian diversity or abundance from auditory point counts with direct estimates of detection probability.}, number={3}, journal={ECOLOGICAL APPLICATIONS}, author={Alldredge, Mathew W. and Simons, Theodore R. and Pollock, Kenneth H.}, year={2007}, month={Apr}, pages={948–955} }
 @article{pollock_yoshizaki_fabrizio_schram_2007, title={Factors affecting survival rates of a recovering lake trout population estimated by mark-recapture in Lake Superior, 1969-1996}, volume={136}, ISSN={["1548-8659"]}, DOI={10.1577/T05-317.1}, abstractNote={Abstract We used data from a long-term Wisconsin Department of Natural Resources mark–recapture study to examine the dynamics of survival in a recovering population of lake trout Salvelinus namaycush in western Lake Superior from 1969 to 1996. Survival rates were estimated using the Cormack–Jolly–Seber method, and a series of models were constructed to examine the effect of year, size, sex, and origin (hatchery versus wild) on the survival rates of lake trout captured within the Gull Island Shoal refuge established in 1976. To select among the models, we used Akaike's information criterion corrected for small sample size and overdispersion. Our estimates of survival rates were adjusted using previously published tag loss rates for the three types of tags used since 1969. Survival estimates for wild fish varied widely among years; the lowest survival rates were observed in 1973 and 1974 and again in 1985 and 1986. Survival rates of wild fish were dependent on sex and size: Survival rates for male lake trou...}, number={1}, journal={TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY}, author={Pollock, Kenneth H. and Yoshizaki, Jun and Fabrizio, Mary C. and Schram, Stephen T.}, year={2007}, month={Jan}, pages={185–194} }
 @article{alldredge_pollock_simons_shriner_2007, title={Multiple-species analysis of point count data: a more parsimonious modelling framework}, volume={44}, ISSN={["1365-2664"]}, DOI={10.1111/j.1365-2664.2006.01271.x}, abstractNote={1 Although population surveys often provide information on multiple species, these data are rarely analysed within a multiple-species framework despite the potential for more efficient estimation of population parameters. 2 We have developed a multiple-species modelling framework that uses similarities in capture/detection processes among species to model multiple species data more parsimoniously. We present examples of this approach applied to distance, time of detection and multiple observer sampling for avian point count data. 3 Models that included species as a covariate and individual species effects were generally selected as the best models for distance sampling, but group models without species effects performed best for the time of detection and multiple observer methods. Population estimates were more precise for no-species-effect models than for species-effect models, demonstrating the benefits of exploiting species’ similarities when modelling multiple species data. Partial species-effect models and additive models were also useful because they modelled similarities among species while allowing for species differences. 4 Synthesis and applications. We recommend the adoption of multiple-species modelling because of its potential for improved population estimates. This framework will be particularly beneficial for modelling count data from rare species because information on the detection process can be ‘borrowed’ from more common species. The multiple-species modelling framework presented here is applicable to a wide range of sampling techniques and taxa.}, number={2}, journal={JOURNAL OF APPLIED ECOLOGY}, author={Alldredge, Mathew W. and Pollock, Kenneth H. and Simons, Theodore R. and Shriner, Susan A.}, year={2007}, month={Apr}, pages={281–290} }
 @article{jiang_pollock_brownie_hoenig_latour_wells_hightower_2007, title={Tag return models allowing for harvest and catch and release: Evidence of environmental and management impacts on striped bass fishing and natural mortality rates}, volume={27}, ISSN={["0275-5947"]}, DOI={10.1577/M06-089.1}, abstractNote={Catch-and-release fisheries have become very important in the management of overexploited recreational fish stocks. Tag return studies, where the tag is removed regardless of fish disposition, have been used to assess the effectiveness of restoration efforts for these fisheries. We extend the instantaneous rate formulation of tag return models to allow for catch and release as well as harvest. The key point of our methods is that, given an estimate of the tag reporting rate, the fishing mortality rate (F) is separated into two components: the mortality on harvested fish and the “mortality” on tags (because the tags are removed) of fish released alive. The total fishing mortality rate for untagged fish is the sum of the Fs due to harvest and hooking mortality suffered by fish released alive. Natural mortality rates can also be estimated. Both age-independent models and age-dependent models are constructed, and the age-dependent models are illustrated by application to data from a study of striped bass Morone saxatilis in Chesapeake Bay from 1991 to 2003 by the Maryland Department of Natural Resources. By fitting models of the natural mortality rate with limited age and year dependence, we demonstrate an overall decrease in natural mortality rates as fish age and provide evidence of an increase in natural mortality beginning in the late 1990s, when an outbreak of the disease mycobacteriosis is thought to have begun. Our results indicate that fishing mortality is age dependent; selectivity increases up to age 6, when fish appear to be fully recruited to the fishery. There is also evidence of an increase in fishing mortality since 1995, when regulations were relaxed.}, number={2}, journal={NORTH AMERICAN JOURNAL OF FISHERIES MANAGEMENT}, author={Jiang, Honghua and Pollock, Kenneth H. and Brownie, Cavell and Hoenig, John M. and Latour, Robert J. and Wells, Brian K. and Hightower, Joseph E.}, year={2007}, month={May}, pages={387–396} }
 @article{pollock_pine_2007, title={The design and analysis of field studies to estimate catch-and-release mortality}, volume={14}, ISSN={["0969-997X"]}, DOI={10.1111/j.1365-2400.2007.00532.x}, abstractNote={Abstract The practice of catch and release (CR) as a fisheries management tool to reduce fishing mortality is widely applied in both freshwater and marine fisheries, whether from shifts in angler attitudes related to harvest or from the increasing use of harvest restrictions such as closed seasons or length limits. This approach assumes that for CR fishing policies to benefit the stock, CR will result in much lower mortality than would otherwise occur. There are many challenges in the design of CR studies to assess mortality, and in many practical settings it is difficult to obtain accurate and precise estimates. The focus of this article is on the design and quantitative aspects of estimating CR mortality, the need for a comprehensive approach that explicitly states all components of CR mortality, and the assumptions behind these methods. A general conceptual model for CR mortality that is applicable to containment and tagging-based studies with a slight modification is presented. This article reviews the design and analysis of containment and tagging studies to estimate CR mortality over both the short and long term and then compares these two approaches. Additionally, the potential population-level impacts of CR mortality are discussed. A recurring theme is the difficulty of designing studies to estimate CR mortality comprehensively and the need for additional research into both statistical model development and field study design.}, number={2}, journal={FISHERIES MANAGEMENT AND ECOLOGY}, author={Pollock, K. H. and Pine, W. E., III}, year={2007}, month={Apr}, pages={123–130} }
 @article{volstad_pollock_richkus_2006, title={Comparing and combining effort and catch estimates from aerial-access designs as applied to a large-scale angler survey in the Delaware River}, volume={26}, ISSN={["0275-5947"]}, DOI={10.1577/M04-146.1}, abstractNote={We used probability-based aerial−access surveys to estimate effort, catch, and harvest of American shad Alosa sapidissima and striped bass Morone saxatilis by recreational anglers in the Delaware River and upper estuary in 2002. Sampling of anglers at access points and flights over the river were conducted weekly from mid-March through October. Daily flight times were randomly selected; probabilities were proportional to the observed distribution of daily angler effort in a prior aerial−access survey (random count). Additional experimental flights were scheduled to occur at the time of day with expected peak effort (maximum count). Effort estimates derived from these maximum counts were more precise than estimates derived from the random flights, but the maximum-count observations caused bias except when the daily count expansions were based on effort distributions from the concurrent access survey. The aerial and access surveys produced similar estimates of boat angler effort and little evidence of bias, but shore anglers were undercounted in the aerial survey. We maximized the precision and minimized bias in total effort estimates by combining the estimates of boat angler effort and shore angler access. An estimated sevenfold increase in the access survey sampling effort (at nearly five times the cost) would be required to achieve the same precision in the total effort estimate produced by the aerial–access survey. Effective stratification and the use of efficient model-based estimators helped us to achieve the target precision of 20% in relative standard error (RSE) for estimated recreational catch of American shad (mean = 26,885 fish; RSE = 16%) and striped bass (mean = 47,671 fish; RSE = 15%). A single access survey during the American shad run would have required a 10-fold increase in sampling effort to achieve the same precision in estimated catch at six times the cost of the complemented surveys.}, number={3}, journal={NORTH AMERICAN JOURNAL OF FISHERIES MANAGEMENT}, author={Volstad, Jon H. and Pollock, Kenneth H. and Richkus, Willlam A.}, year={2006}, month={Aug}, pages={727–741} }
 @article{taylor_whittington_pine_pollock_2006, title={Effect of different reward levels on tag reporting rates and behavior of common snook anglers in southeast Florida}, volume={26}, ISSN={["1548-8675"]}, DOI={10.1577/M04-185.1}, abstractNote={Based on the high-reward tagging method, we determined that reporting rates by recreational anglers for tagged common snook Centropomus undecimalis along the Atlantic coast of Florida were approximately 60–70%. Additionally, we found that angler reporting rates were influenced by the use of high-reward tags. To estimate reporting rates, we tagged 989 common snook (range = 600–1,132 mm total length) with internal anchor tags that bore one of eight variable-reward messages (the word “Reward” with or without a specified monetary amount from US$5 to $200) during the summer closed-harvest season of 1995. Approximately equal numbers and sizes of fish were tagged in each reward group. The $200 reward was assumed to be sufficient to elicit a reporting rate of 100%. Return rates during the first year were quite variable and ranged from 13.7% for $5 tags to 25.0% for $25 tags, while the $200 tags had a return rate of 18.7%. Return rates generally increased with increasing reward amount, reaching an asymptotic value at approximately $75 in year 1 and $100 in year 2, above which return rates did not change. In subsequent years, angler behavior appeared to change, as indicated by decreases in the reporting rate of unspecified “Reward” message tags and an increase in the asymptote of the reward level–return rate relationship. This may indicate that angler reporting behavior changed due to the use of high-reward tags. The results from this experiment will facilitate the deconstruction of total mortality into fishing and natural mortality components derived from tagging programs. They also provide insight into angler behavior related to the design and use of high-reward tagging programs to elicit tag returns.}, number={3}, journal={NORTH AMERICAN JOURNAL OF FISHERIES MANAGEMENT}, author={Taylor, Ronald G. and Whittington, James A. and Pine, William E., III and Pollock, Kenneth H.}, year={2006}, month={Aug}, pages={645–651} }
 @article{pollock_marsh_lawler_alldredge_2006, title={Estimating animal abundance in heterogeneous environments: An application to aerial surveys for Dugongs}, volume={70}, ISSN={["1937-2817"]}, DOI={10.2193/0022-541X(2006)70[255:EAAIHE]2.0.CO;2}, abstractNote={The probability of detecting an animal in a sampled area during a survey consists of 2 components: 1) the probability of an animal being available for detection (availability), which can be highly variable in heterogeneous environments; and 2) the probability of an animal being detected, conditional on its being available for detection (perception). Many surveys only estimate the latter probability because modeling the availability process requires information collected external to the survey. We illustrate estimation of both probabilities in an application to aerial surveys of dugongs (Dugong dugon) in Northern Australian coastal waters where water clarity varies greatly over relatively small spatial scales. Using artificial dugong models and timed depth recorders deployed on 15 wild dugongs to obtain dive profiles, we carried out experiments to determine zones of detectability for dugongs at the range of depths, turbidities, and sea states that spanned the environmental heterogeneity encountered on dugong surveys. Resulting probability estimates were heterogeneous and dependent on the measured conditions. To estimate perception probability, we used a tandem team of 2 observers on either side of the aircraft. This permitted fitting generalized Lincoln–Petersen models with Program MARK. We then used the generalized Horvitz–Thompson estimator, based on the overall detection probability for each individual dugong, to generate population estimates. We also developed a new simulation-based method for estimating standard errors and confidence intervals. We contrast absolute abundance estimates of dugongs in the Torres Strait and Northern Great Barrier Reef regions using both the new and original approaches (Marsh and Sinclair 1989a). For Torres Strait, the new method produced a substantially smaller estimate (11,956 vs. 14,106 dugongs) and a very much smaller standard error (1,189 vs. 2,314 dugongs), whereas the new method produced slightly larger estimates (mean 9,855 vs. 9,193 dugongs, standard error 1,184 vs. 917 dugongs) for the Northern Great Barrier Reef survey.}, number={1}, journal={JOURNAL OF WILDLIFE MANAGEMENT}, author={Pollock, KH and Marsh, HD and Lawler, IR and Alldredge, MW}, year={2006}, pages={255–262} }
 @article{alldredge_pollock_simons_2006, title={Estimating detection probabilities from multiple-observer point counts}, volume={123}, ISSN={["1938-4254"]}, DOI={10.1642/0004-8038(2006)123[1172:EDPFMP]2.0.CO;2}, abstractNote={Abstract Point counts are commonly used to obtain indices of bird population abundance. We present an independent-observer point-count method, a generalization of the dependent-observer approach, based on closed-population capture- recapture methods. The approach can incorporate individual covariates, such as detection distance, to account for individual differences in detection probabilities associated with measurable sources of variation. We demonstrate a negative bias in two-observer estimates by comparing abundance estimates from two- and four- observer point counts. Models incorporating data from four independent observers were capable of accounting for this bias. Modeling individual bird differences in detection probabilities produced abundance estimates 15–21% higher than models that did not account for individual differences, in four out of five data sets analyzed. Although independent-observer methods are expensive and impractical for large- scale applications, we believe they can provide importa...}, number={4}, journal={AUK}, author={Alldredge, Mathew W. and Pollock, Kenneth H. and Simons, Theodore R.}, year={2006}, month={Oct}, pages={1172–1182} }
 @article{polacheck_eveson_laslett_pollock_hearn_2006, title={Integrating catch-at-age and multiyear tagging data: a combined Brownie and Petersen estimation approach in a fishery context}, volume={63}, ISSN={["1205-7533"]}, DOI={10.1139/f05-232}, abstractNote={A comprehensive framework for modelling data from multiyear tagging experiments in a fishery context is presented that incorporates catch data into the traditional Brownie tag–recapture model. Incorporation of catch data not only allows for improved estimation of natural and fishing mortality rates, but also for direct estimation of population size at the time of tagging. These are the primary quantities required to be estimated in stock assessments — having an approach for directly estimating them that does not require catch rates provides a potentially powerful alternative for augmenting traditional stock assessment methods. Simulations are used to demonstrate the value of directly incorporating catch data in the model. Results from the range of scenarios considered suggest that in addition to providing a precise estimate of population size (coefficients of variation ranging from ~15% to 30%), including catch data can decrease biases in the mortality rate estimates (natural mortality especially) and improve precision of fishing mortality rate estimates (by as much as 60% at age 1). The model is applied to southern bluefin tuna (Thunnus maccoyii) tag–recapture and catch data collected in the 1990s to provide estimates of natural mortality, fishing mortality, and abundance for five cohorts of fish.}, number={3}, journal={CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES}, author={Polacheck, T and Eveson, JP and Laslett, GM and Pollock, KH and Hearn, WS}, year={2006}, month={Mar}, pages={534–548} }
 @article{leigh_hearn_pollock_2006, title={Time-dependent instantaneous mortality rates from multiple tagging experiments with exact times of release and recovery}, volume={13}, ISSN={["1573-3009"]}, DOI={10.1007/s10651-005-5693-z}, number={1}, journal={ENVIRONMENTAL AND ECOLOGICAL STATISTICS}, author={Leigh, GM and Hearn, WS and Pollock, KH}, year={2006}, month={Mar}, pages={89–108} }
 @article{alpizar-jara_pollock_haines_2005, title={Mark-recapture estimators for dual frame population size of prominent nesting structures: the effect of uncertain detection probability}, volume={12}, ISSN={["1352-8505"]}, DOI={10.1007/s10651-005-1039-0}, abstractNote={The combined mark-recapture and line transect sampling methodology proposed by Alpizar-Jara and Pollock [Journal of Environmental and Ecological Statistics, 3(4), 311–327, 1996; In Marine Mammal Survey and Assessment Methods Symposium. G.W. Garner, S.C. Amstrup, J.L. Laake, B.F.J. Manly, L.L. McDonald, and D.C. Robertson (Eds.), A.A. Balkema, Rotterdam, Netherlands, pp. 99–114, 1999] is used to illustrate the estimation of population size for populations with prominent nesting structures (i.e., bald eagle nests). In the context of a bald eagle population, the number of nests in a list frame corresponds to a “pre-marked” sample of nests, and an area frame corresponds to a set of transect strips that could be regularly monitored. Unlike previous methods based on dual frame methodology using the screening estimator [Haines and Pollock (Journal of Environmental and Ecological Statistics, 5, 245–256, 1998a; Survey Methodology, 24(1), 79–88, 1998b)], we no longer need to assume that the area frame is complete (i.e., all the nests in the sampled sites do not need to be seen). One may use line transect sampling to estimate the probability of detection in a sampled area. Combining information from list and area frames provides more efficient estimators than those obtained by using data from only one frame. We derive an estimator for detection probability and generalize the screening estimator. A simulation study is carried out to compare the performance of the Chapman modification of the Lincoln–Petersen estimator to the screening estimator. Simulation results show that although the Chapman estimator is generally less precise than the screening estimator, the latter can be severely biased in presence of uncertain detection. The screening estimator outperforms the Chapman estimator in terms of mean squared error when detection probability is near 1 wheareas the Chapman estimator outperforms the screening estimator when detection probability is lower than a certain threshold value depending on particular scenarios.}, number={2}, journal={ENVIRONMENTAL AND ECOLOGICAL STATISTICS}, author={Alpizar-Jara, R and Pollock, K and Haines, D}, year={2005}, month={Jun}, pages={155–168} }
 @article{marsh_lawler_kwan_delean_pollock_alldredge_2004, title={Aerial surveys and the potential biological removal technique indicate that the Torres Strait dugong fishery is unsustainable}, volume={7}, ISSN={["1469-1795"]}, DOI={10.1017/S1367943004001635}, abstractNote={The globally significant dugong population of Torres Strait supports an important indigenous fishery for meat and oil. The fishery is protected by the Torres Strait Treaty between Australia and Papua New Guinea. A time series of aerial survey estimates from 1987–2001 confirms that there is considerable temporal variability in the size of the dugong population in the region and adds to a growing body of evidence from other aerial surveys and satellite tracking that dugongs undertake large-scale movements associated with temporal and spatial changes in the distribution of their seagrass food. The magnitude of these effects on both the size of the population and the catch cannot be disaggregated from the effects of population depletion from over-harvesting. The Potential Biological Removal method was used in conjunction with the aerial survey data to estimate sustainable anthropogenic mortality from all causes for a range of empirically-derived estimates of dugong life-history parameters. These estimates of a sustainable harvest are so far below the current harvest that it must be unsustainable. Governments should heed the Islanders' requests for assistance in implementing co-management of the fishery as a matter of urgency.}, journal={ANIMAL CONSERVATION}, author={Marsh, H and Lawler, IR and Kwan, D and Delean, S and Pollock, K and Alldredge, M}, year={2004}, month={Nov}, pages={435–443} }
 @article{pollock_jiang_hightower_2004, title={Combining telemetry and fisheries tagging models to estimate fishing and natural mortality rates}, volume={133}, ISSN={["1548-8659"]}, DOI={10.1577/T03-029.1}, abstractNote={Abstract The traditional multiple-year tag return method is a fundamental approach to estimating fishing and natural mortality rates in fisheries. It can provide reliable and precise estimation of the parameters when the tag reporting rate, λ, is known. However, it is often difficult to estimate λ accurately. An additional disadvantage is that this method has to estimate natural mortality indirectly because natural deaths are not observable. Recently, fisheries biologists have begun to implement telemetry methods to estimate fishing and natural mortality. The advantage of a telemetry method is that it contains direct information about natural mortality and survival. A shortcoming is that there is no direct information on fishing deaths. In this paper, we combine the two methods, using direct information about both fishing and natural mortality to obtain more precise and effectively unbiased parameter estimates, including reporting rate estimates for the regular tags. Using simulation when the telemetry ta...}, number={3}, journal={TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY}, author={Pollock, KH and Jiang, HH and Hightower, JE}, year={2004}, month={May}, pages={639–648} }
 @article{bailey_simons_pollock_2004, title={Comparing population size estimators for plethodontid salamanders}, volume={38}, ISSN={["1937-2418"]}, DOI={10.1670/194-03A}, abstractNote={Despite concern over amphibian declines, few studies estimate absolute abundances because of logistic and economic constraints and previously poor estimator performance. Two estimation approaches recommended for amphibian studies are mark-recapture and depletion (or removal) sampling. We compared abundance estimation via various mark-recapture and depletion methods, using data from a three-year study of terrestrial salamanders in Great Smoky Mountains National Park. Our results indicate that short-term closed-population, robust design, and depletion methods estimate surface population of salamanders (i.e., those near the surface and available for capture during a given sampling occasion). In longer duration studies, temporary emigration violates assumptions of both open- and closed-population mark-recapture estimation models. However, if the temporary emigration is completely random, these models should yield unbiased estimates of the total population (superpopulation) of salamanders in the sampled area. We recommend using Pollock's robust design in mark-recapture studies because of its flexibility to incorporate variation in capture probabilities and to estimate temporary emigration probabilities.}, number={3}, journal={JOURNAL OF HERPETOLOGY}, author={Bailey, LL and Simons, TR and Pollock, KH}, year={2004}, month={Sep}, pages={370–380} }
 @article{bailey_simons_pollock_2004, title={Estimating detection probability parameters for plethodon salamanders using the robust capture-recapture design}, volume={68}, number={1}, journal={Journal of Wildlife Management}, author={Bailey, L. L. and Simons, T. R. and Pollock, K. H.}, year={2004}, pages={13-} }
 @article{bailey_simons_pollock_2004, title={Estimating site occupancy and species detection probability parameters for terrestrial salamanders}, volume={14}, ISSN={["1051-0761"]}, DOI={10.1890/03-5012}, abstractNote={Recent, worldwide amphibian declines have highlighted a need for more extensive and rigorous monitoring programs to document species occurrence and detect population change. Abundance estimation methods, such as mark–recapture, are often expensive and impractical for large-scale or long-term amphibian monitoring. We apply a new method to estimate proportion of area occupied using detection/nondetection data from a terrestrial salamander system in Great Smoky Mountains National Park. Estimated species-specific detection probabilities were all <1 and varied among seven species and four sampling methods. Time (i.e., sampling occasion) and four large-scale habitat characteristics (previous disturbance history, vegetation type, elevation, and stream presence) were important covariates in estimates of both proportion of area occupied and detection probability. All sampling methods were consistent in their ability to identify important covariates for each salamander species. We believe proportion of area occupie...}, number={3}, journal={ECOLOGICAL APPLICATIONS}, author={Bailey, LL and Simons, TR and Pollock, KH}, year={2004}, month={Jun}, pages={692–702} }
 @article{bailey_simons_pollock_2004, title={Spatial and temporal variation in detection probability of plethodon salamanders using the robust capture-recapture design}, volume={68}, ISSN={["0022-541X"]}, DOI={10.2193/0022-541X(2004)068[0014:SATVID]2.0.CO;2}, abstractNote={Recent worldwide amphibian declines have highlighted a need for long-term, large-scale monitoring programs. Scientific or management objectives, appropriate spatial sampling, and detectability all must be considered when designing monitoring programs (Yoccoz et al. 2001). The ability to establish meaningful monitoring programs currently is compromised by a lack of information about amphibian detection probabilities. We used Pollock's robust design and capture–recapture models that included temporary emigration to test a priori hypotheses about spatial and temporal variation in salamander detection probability parameters for populations found in Great Smoky Mountains National Park (Tennessee/North Carolina), USA. We explored the effects of 3 large-scale habitat characteristics (disturbance history, elevation, vegetation type) and found that vegetation type and elevation were correlated with detection probabilities. Vegetation type was an important covariant in estimates of temporary emigration, conditional capture probability, and surface population size. Contrasts that isolated elevation effects were significant for all detection probability parameters except recapture probability, despite our small elevational range (330 m). When detection probability parameters have the potential to vary over time and space, investigators should develop monitoring designs that permit the estimation of detection probabilities.}, number={1}, journal={JOURNAL OF WILDLIFE MANAGEMENT}, author={Bailey, LL and Simons, TR and Pollock, KH}, year={2004}, month={Jan}, pages={14–24} }
 @article{nasution_brownie_pollock_powell_2004, title={The effect on model identifiability of allowing different relocation rates for live and dead animals in the combined analysis of telemetry and recapture data}, volume={9}, ISSN={["1085-7117"]}, DOI={10.1198/1085711043181}, abstractNote={Models are described for the joint analysis of live-trapping and radio telemetry data from a study on black bears (Ursus americanus) in which all animals received ear tags and a subset also received radio tags. Concerns about bias in survival estimates led to investigation of identifiability and estimator precision for a series of models that allowed differenttelemetry relocation rates for living and dead animals, in addition to emigration and seasonal variation in survival. Identifiability was determined by showing that the expected information matrix was nonsingular. Models with fidelity constant across time, and with the same degree of time specificity for survival rates and relocation rates for dead animals, were determined to be nonidentifiable. More general models, with a greater degree of time specificity for survival rates, were near-singular, and estimators under these near-singular models had poor precision. Analysis of data from the study on black bears illustrated that estimates of survival have poor precision when relocation rates are estimated separately for live and dead animals. It is recommended that the effort expended to relocate both living and dead animals be consistently high in each telemetry survey, so that relocation rates will be high and constant across time and mortality status.}, number={1}, journal={JOURNAL OF AGRICULTURAL BIOLOGICAL AND ENVIRONMENTAL STATISTICS}, author={Nasution, MD and Brownie, C and Pollock, KH and Powell, RA}, year={2004}, month={Mar}, pages={27–41} }
 @article{alpizar-jara_nichols_hines_sauer_pollock_rosenberry_2004, title={The relationship between species detection probability and local extinction probability}, volume={141}, ISSN={["0029-8549"]}, DOI={10.1007/s00442-004-1641-0}, abstractNote={In community-level ecological studies, generally not all species present in sampled areas are detected. Many authors have proposed the use of estimation methods that allow detection probabilities that are <1 and that are heterogeneous among species. These methods can also be used to estimate community-dynamic parameters such as species local extinction probability and turnover rates (Nichols et al. Ecol Appl 8:1213–1225; Conserv Biol 12:1390–1398). Here, we present an ad hoc approach to estimating community-level vital rates in the presence of joint heterogeneity of detection probabilities and vital rates. The method consists of partitioning the number of species into two groups using the detection frequencies and then estimating vital rates (e.g., local extinction probabilities) for each group. Estimators from each group are combined in a weighted estimator of vital rates that accounts for the effect of heterogeneity. Using data from the North American Breeding Bird Survey, we computed such estimates and tested the hypothesis that detection probabilities and local extinction probabilities were negatively related. Our analyses support the hypothesis that species detection probability covaries negatively with local probability of extinction and turnover rates. A simulation study was conducted to assess the performance of vital parameter estimators as well as other estimators relevant to questions about heterogeneity, such as coefficient of variation of detection probabilities and proportion of species in each group. Both the weighted estimator suggested in this paper and the original unweighted estimator for local extinction probability performed fairly well and provided no basis for preferring one to the other.}, number={4}, journal={OECOLOGIA}, author={Alpizar-Jara, R and Nichols, JD and Hines, JE and Sauer, JR and Pollock, KH and Rosenberry, CS}, year={2004}, month={Dec}, pages={652–660} }
 @misc{pine_pollock_hightower_kwak_rice_2003, title={A review of tagging methods for estimating fish population size and components of mortality}, volume={28}, ISSN={["1548-8446"]}, DOI={10.1577/1548-8446(2003)28[10:AROTMF]2.0.CO;2}, abstractNote={Techniques to improve estimation of animal population size and mortality from tagging studies have received substantial attention from terrestrial biologists and statisticians during the last 20 years. However, these techniques have received little notice from fisheries biologists, despite the widespread applicability to fisheries research, the wide variety of tag types used in fisheries research (from traditional fin clips to telemetry tags), and the development of new computer software to assist with analyses. We present a brief review of population models based on recaptures, returns, or telemetry relocations of tagged fish that can be used to estimate population size, total mortality, and components of mortality (i.e., fishing and natural) that are frequently of interest to fisheries biologists. Recommended strategies include (1) use closed population models (e.g., Lincoln-Peterson) to estimate population size for short term studies where closure assumption can be met, (2) use the robust design to estimate population size for studies of longer duration, (3) use high-reward tags in conjunction with other methods of estimating reporting rate in tag-return studies, (4) combine a subset of telemetry tagged fish with either a high-reward tagging program or a traditional capture-recapture study to improve mortality estimates and understanding of mortality components, and (5) use pilot studies and simulation analyses to assess precision of estimated parameters to evaluate study feasibility. Incorporation of these improved techniques could lead to greater accuracy and precision of parameter estimates from tagging studies and thus to improved understanding and management of fish populations.}, number={10}, journal={FISHERIES}, author={Pine, WE and Pollock, KH and Hightower, JE and Kwak, TJ and Rice, JA}, year={2003}, month={Oct}, pages={10–23} }
 @article{meador_mcintyre_pollock_2003, title={Assessing the efficacy of single-pass backpack electrofishing to characterize fish community structure}, volume={132}, ISSN={["0002-8487"]}, DOI={10.1577/1548-8659(2003)132<0039:ATEOSP>2.0.CO;2}, abstractNote={Two-pass backpack electrofishing data collected as part of the U.S. Geological Survey's National Water-Quality Assessment Program were analyzed to assess the efficacy of single-pass backpack electrofishing. A two-capture removal model was used to estimate, within 10 river basins across the United States, proportional fish species richness from one-pass electrofishing and probabilities of detection for individual fish species. Mean estimated species richness from first-pass sampling ([pcirc],s1) ranged from 80.7% to 100% of estimated total species richness for each river basin, based on at least seven samples per basin. However, [pcirc],s1 values for individual sites ranged from 40% to 100% of estimated total species richness. Additional species unique to the second pass were collected in 50.3% of the samples. Of these, cyprinids and centrarchids were collected most frequently. Proportional fish species richness estimated for the first pass increased significantly with decreasing stream width for 1 of the 10 river basins. When used to calculate probabilities of detection of individual fish species, the removal model failed 48% of the time because the number of individuals of a species was greater in the second pass than in the first pass. Single-pass backpack electrofishing data alone may make it difficult to determine whether characterized fish community structure data are real or spurious. The two-pass removal model can be used to assess the effectiveness of sampling species richness with a single electrofishing pass. However, the two-pass removal model may have limited utility to determine probabilities of detection of individual species and, thus, limit the ability to assess the effectiveness of single-pass sampling to characterize species relative abundances. Multiple-pass (at least three passes) backpack electrofishing at a large number of sites may not be cost-effective as part of a standardized sampling protocol for large-geographic-scale studies. However, multiple-pass electrofishing at some sites may be necessary to better evaluate the adequacy of single-pass electrofishing and to help make meaningful interpretations of fish community structure.}, number={1}, journal={TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY}, author={Meador, MR and McIntyre, JP and Pollock, KH}, year={2003}, month={Jan}, pages={39–46} }
 @article{pledger_pollock_norris_2003, title={Open capture-recapture models with heterogeneity: I. Cormack-Jolly-Seber model}, volume={59}, ISSN={["0006-341X"]}, DOI={10.1111/j.0006-341X.2003.00092.x}, abstractNote={In open population capture-recapture studies, it is usually assumed that similar animals (e.g., of the same sex and age group) have similar survival rates and capture probabilities. These assumptions are generally perceived to be an oversimplification, and they can lead to incorrect model selection and biased parameter estimates. Allowing for individual variability in survival and capture probabilities among apparently similar animals is now becoming possible, due to advances in closed population models and improved computing power. This article presents a flexible framework of likelihood-based models which allow for individual heterogeneity in survival and capture rates. Heterogeneity is modeled using finite mixtures, which have enough flexibility of distribution shape to accommodate a wide variety of different patterns of individual variation. The models condition on the first capture of each animal, and include as a special case the Cormack-Jolly-Seber model. Model selection is done either using Akaike's information criterion or by likelihood ratio tests, making available checks of different influences on survival rates. Bias in parameter estimates is reduced by including individual heterogeneity. Model selection and bias reduction are important in population studies and for making informed management decisions.}, number={4}, journal={BIOMETRICS}, author={Pledger, S and Pollock, KH and Norris, JL}, year={2003}, month={Dec}, pages={786–794} }
 @article{pollock_2003, title={Recreational angler surveys: The interaction of scale and optimal contact methods for effort and catch estimation}, ISBN={9780724530960}, number={67}, journal={Fishery Status Reports}, publisher={Department of Primary Industry and Fisheries, Northern Territory of Australia}, author={Pollock, K. H.}, year={2003}, pages={33} }
 @article{anderson_cooch_gutierrez_krebs_lindberg_pollock_ribic_shenk_2003, title={Rigorous science: suggestions on how to raise the bar}, volume={31}, number={1}, journal={Wildlife Society Bulletin}, author={Anderson, D. R. and Cooch, E. G. and Gutierrez, R. J. and Krebs, C. J. and Lindberg, M. S. and Pollock, K. H. and Ribic, C. A. and Shenk, T. M.}, year={2003}, pages={296–305} }
 @article{hearn_hoenig_pollock_hepworth_2003, title={Tag reporting rate estimation: 3. Use of planted tags in one component of a multiple-component fishery}, volume={23}, ISSN={["1548-8675"]}, DOI={10.1577/1548-8675(2003)023<0066:TRREUO>2.0.CO;2}, abstractNote={Tag return models are used to estimate survival and tag recovery rates. With additional information on tag reporting rates, one can separate the survival rate into its fishing and natural mortality rate components. One method of estimating the tag reporting rate is to secretly plant tags in fishers' catches. However, if the fishery has more than one component, it may not be possible to plant tags in all components. Nevertheless, it is possible to estimate the reporting rates of all components in a multiple-component fishery and the fishing and natural mortality rates, if at least one component has a known reporting rate and the catches are known for each component. We simulate a variety of tag return experiments in which tags are planted in one component of a multicomponent fishery. The simulations show that this method is most effective (i.e., provides good precision of parameter estimates) when a sufficient number of tagged fish are planted into a fishery component with a high reporting rate and with a high proportion of the total catch. It is also advantageous to encourage the reporting of tags in the fishery components without planted tags. We provide a method for testing various model assumptions when it is possible to plant tags in more than one component.}, number={1}, journal={NORTH AMERICAN JOURNAL OF FISHERIES MANAGEMENT}, author={Hearn, WS and Hoenig, JM and Pollock, KH and Hepworth, DA}, year={2003}, month={Feb}, pages={66–77} }
 @article{pollock_hearn_polacheck_2002, title={A general model for tagging on multiple component fisheries: an integration of age-dependent reporting rates and mortality estimation}, volume={9}, ISSN={["1573-3009"]}, DOI={10.1023/A:1013715008683}, number={1}, journal={ENVIRONMENTAL AND ECOLOGICAL STATISTICS}, author={Pollock, KH and Hearn, WS and Polacheck, T}, year={2002}, month={Mar}, pages={57–69} }
 @article{farnsworth_pollock_nichols_simons_hines_sauer_2002, title={A removal model for estimating detection probabilities from point-count surveys}, volume={119}, ISSN={["1938-4254"]}, DOI={10.1642/0004-8038(2002)119[0414:ARMFED]2.0.CO;2}, abstractNote={Use of point-count surveys is a popular method for collecting data on abundance and distribution of birds. However, analyses of such data often ignore potential differences in detection probability. We adapted a removal model to directly estimate detection probability during point-count surveys. The model assumes that singing frequency is a major factor influencing probability of detection when birds are surveyed using point counts. This may be appropriate for surveys in which most detections are by sound. The model requires counts to be divided into several time intervals. Point counts are often conducted for 10 min, where the number of birds recorded is divided into those first observed in the first 3 min, the subsequent 2 min, and the last 5 min. We developed a maximum-likelihood estimator for the detectability of birds recorded during counts divided into those intervals. This technique can easily be adapted to point counts divided into intervals of any length. We applied this method to unlimited-radius counts conducted in Great Smoky Mountains National Park. We used model selection criteria to identify whether detection probabilities varied among species, throughout the morning, throughout the season, and among different observers. We found differences in detection probability among species. Species that sing frequently such as Winter Wren (Troglodytes troglodytes) and Acadian Flycatcher (Empidonax virescens) had high detection probabilities (∼90%) and species that call infrequently such as Pileated Woodpecker (Dryocopus pileatus) had low detection probability (36%). We also found detection probabilities varied with the time of day for some species (e.g. thrushes) and between observers for other species. We used the same approach to estimate detection probability and density for a subset of the observations with limited-radius point counts.}, number={2}, journal={AUK}, author={Farnsworth, GL and Pollock, KH and Nichols, JD and Simons, TR and Hines, JE and Sauer, JR}, year={2002}, month={Apr}, pages={414–425} }
 @article{brooks_alpizar-jara_pollock_steffen_pack_norman_2002, title={An online wild turkey population dynamics model}, volume={30}, number={1}, journal={Wildlife Society Bulletin}, author={Brooks, E. N. and Alpizar-Jara, R. and Pollock, K. H. and Steffen, D. E. and Pack, J. C. and Norman, G. W.}, year={2002}, pages={41–45} }
 @article{pollock_nichols_simons_farnsworth_bailey_sauer_2002, title={Large scale wildlife monitoring studies: statistical methods for design and analysis}, volume={13}, ISSN={["1099-095X"]}, DOI={10.1002/env.514}, abstractNote={Techniques for estimation of absolute abundance of wildlife populations have received a lot of attention in recent years. The statistical research has been focused on intensive small-scale studies. Recently, however, wildlife biologists have desired to study populations of animals at very large scales for monitoring purposes. Population indices are widely used in these extensive monitoring programs because they are inexpensive compared to estimates of absolute abundance. A crucial underlying assumption is that the population index (C) is directly proportional to the population density (D). The proportionality constant, β, is simply the probability of ‘detection’ for animals in the survey. As spatial and temporal comparisons of indices are crucial, it is necessary to also assume that the probability of detection is constant over space and time. Biologists intuitively recognize this when they design rigid protocols for the studies where the indices are collected. Unfortunately, however, in many field studies the assumption is clearly invalid. We believe that the estimation of detection probability should be built into the monitoring design through a double sampling approach. A large sample of points provides an abundance index, and a smaller sub-sample of the same points is used to estimate detection probability. There is an important need for statistical research on the design and analysis of these complex studies. Some basic concepts based on actual avian, amphibian, and fish monitoring studies are presented in this article. Copyright © 2002 John Wiley & Sons, Ltd.}, number={2}, journal={ENVIRONMETRICS}, author={Pollock, KH and Nichols, JD and Simons, TR and Farnsworth, GL and Bailey, LL and Sauer, JR}, year={2002}, month={Mar}, pages={105–119} }
 @article{nasution_brownie_pollock_2002, title={Optimal allocation of sample sizes between regular banding and radio-tagging for estimating annual survival and emigration rates}, volume={29}, ISSN={["0266-4763"]}, DOI={10.1080/02664760120108863}, abstractNote={Many authors have shown that a combined analysis of data from two or more types of recapture survey brings advantages, such as the ability to provide more information about parameters of interest. For example, a combined analysis of annual resighting and monthly radio-telemetry data allows separate estimates of true survival and emigration rates, whereas only apparent survival can be estimated from the resighting data alone. For studies involving more than one type of survey, biologists should consider how to allocate the total budget to the surveys related to the different types of marks so that they will gain optimal information from the surveys. For example, since radio tags and subsequent monitoring are very costly, while leg bands are cheap, the biologists should try to balance costs with information obtained in deciding how many animals should receive radios. Given a total budget and specific costs, it is possible to determine the allocation of sample sizes to different types of marks in order to minimize the variance of parameters of interest, such as annual survival and emigration rates. In this paper, we propose a cost function for a study where all birds receive leg bands and a subset receives radio tags and all new releases occur at the start of the study. Using this cost function, we obtain the allocation of sample sizes to the two survey types that minimizes the standard error of survival rate estimates or, alternatively, the standard error of emigration rates. Given the proposed costs, we show that for high resighting probability, e.g. 0.6, tagging roughly 10-40% of birds with radios will give survival estimates with standard errors within the minimum range. Lower resighting rates will require a higher percentage of radioed birds. In addition, the proposed costs require tagging the maximum possible percentage of radioed birds to minimize the standard error of emigration estimates.}, number={1-4}, journal={JOURNAL OF APPLIED STATISTICS}, author={Nasution, MD and Brownie, C and Pollock, KH}, year={2002}, pages={443–457} }
 @article{latour_hoenig_pollock_2002, title={Properties of the residuals from two tag-recovery models}, volume={100}, number={4}, journal={Fishery Bulletin (Washington, D.C.)}, author={Latour, R. J. and Hoenig, J. M. and Pollock, K. H.}, year={2002}, pages={856–860} }
 @article{joe_pollock_2002, title={Separation of survival and movement rates in multi-state tag-return and capture-recapture models}, volume={29}, ISSN={["0266-4763"]}, DOI={10.1080/02664760120108836}, abstractNote={Abstract There has been growing interest in the estimation of transition probabilities among stages (Hestbeck et al. , 1991; Brownie et al. , 1993; Schwarz et al. , 1993) in tag-return and capture-recapture models. This has been driven by the increasing interest in meta-population models in ecology and the need for parameter estimates to use in these models. These transition probabilities are composed of survival and movement rates, which can only be estimated separately when an additional assumption is made (Brownie et al. , 1993). Brownie et al. (1993) assumed that movement occurs at the end of the interval between time i and i + 1. We generalize this work to allow different movement patterns in the interval for multiple tag-recovery and capture-recapture experiments. The time of movement is a random variable with a known distribution. The model formulations can be viewed as matrix extensions to the model formulations of single open population capturerecapture and tag-recovery experiments (Jolly, 1965; Seber, 1965; Brownie et al. , 1985). We also present the results of a small simulation study for the tag-return model when movement time follows a beta distribution, and later another simulation study for the capture-recapture model when movement time follows a uniform distribution. The simulation studies use a modified program SURVIV (White, 1983). The Relative Standard Errors (RSEs) of estimates according to high and low movement rates are presented. We show there are strong correlations between movement and survival estimates in the case that the movement rate is high. We also show that estimators of movement rates to different areas and estimators of survival rates in different areas have substantial correlations.}, number={1-4}, journal={JOURNAL OF APPLIED STATISTICS}, author={Joe, M and Pollock, KH}, year={2002}, pages={373–384} }
 @article{pollock_hoenig_hearn_calingaert_2002, title={Tag reporting rate estimation: 2. Use of high-reward tagging and observers in multiple-component fisheries}, volume={22}, ISSN={["1548-8675"]}, DOI={10.1577/1548-8675(2002)022<0727:TRREUO>2.0.CO;2}, abstractNote={Abstract Tag return models can be used to estimate survival and tag recovery rates. The additional knowledge of an estimated tag reporting rate allows separation of the total mortality rate into fishing and natural mortality components. We briefly review two methods for estimating tag reporting rates: high-reward tags with a 100% reporting rate, and catch from multiple-component fisheries with a 100% reporting rate in one component (e.g., due to the presence of observers in a boat-based commercial fishery). The assumptions of each method are presented and discussed. We simulated the effects of combining the two methods to obtain more robust estimates of the tag reporting rate and other important parameters, such as the exploitation rate. When high-reward tags did not produce a 100% reporting rate or when the observer component in a multiple-component fishery did not have a 100% reporting rate, the combination of methods provided better estimates. It is still necessary to assume that the high-reward tags i...}, number={3}, journal={NORTH AMERICAN JOURNAL OF FISHERIES MANAGEMENT}, author={Pollock, KH and Hoenig, JM and Hearn, WS and Calingaert, B}, year={2002}, month={Aug}, pages={727–736} }
 @misc{pollock_2002, title={The use of auxiliary variables in capture-recapture modelling: an overview}, volume={29}, ISSN={["1360-0532"]}, DOI={10.1080/02664760120108430}, abstractNote={I review the use of auxiliary variables in capture- recapture models for estimation of demographic parameters (e.g. capture probability, population size, survival probability, and recruitment, emigration and immigration numbers). I focus on what has been done in current research and what still needs to be done. Typically in the literature, covariate modelling has made capture and survival probabilities functions of covariates, but there are good reasons also to make other parameters functions of covariates as well. The types of covariates considered include environmental covariates that may vary by occasion but are constant over animals, and individual animal covariates that are usually assumed constant over time. I also discuss the di˝ culties of using time-dependent individual animal covariates and some possible solutions. Covariates are usually assumed to be measured without error, and that may not be realistic. For closed populations, one approach to modelling heterogeneity in capture probabilities uses observable individual covariates and is thus related to the primary purpose of this paper. The now standard Huggins- Alho approach conditions on the captured animals and then uses a generalized Horvitz-Thompson estimator to estimate population size. This approach has the advantage of simplicity in that one does not have to specify a distribution for the covariates, and the disadvantage is that it does not use the full likelihood to estimate population size. Alternately one could specify a distribution for the covariates and implement a full likelihood approach to inference to estimate the capture function, the covariate probability distribution, and the population size. The general Jolly- Seber open model enables one to estimate capture probability, population sizes, survival rates, and birth numbers. Much of the focus on modelling covariates in program MARK has been for survival and capture probability in the Cormack-Jolly-Seber model and its generalizations (including tag-return models). These models condition on the number of animals marked and released. A related, but distinct,}, number={1-4}, journal={JOURNAL OF APPLIED STATISTICS}, author={Pollock, KH}, year={2002}, pages={85–102} }
 @article{pollock_2002, title={What shall we teach in environmental statistics? Discussion}, volume={9}, number={2}, journal={Environmental and Ecological Statistics}, author={Pollock, K. H.}, year={2002}, pages={143} }
 @article{latour_hoenig_olney_pollock_2001, title={A simple test for nonmixing in multiyear tagging studies: Application to striped bass tagged in the Rappahannock River, Virginia}, volume={130}, ISSN={["1548-8659"]}, DOI={10.1577/1548-8659(2001)130<0848:ASTFNI>2.0.CO;2}, abstractNote={The Brownie-type models for multiyear tagging studies allow the estimation of age-specific and year-specific total survival. An important assumption of these models is that the tagged cohorts are thoroughly mixed, or more specifically, that they have identical spatial distributions. We propose a chi-square test to assess the validity of this assumption and apply the method to striped bass tagging data from the Rappahannock River, Virginia. The current protocol for estimating striped bass survival involves fitting a suite of Brownie-type models to tag recovery data. Because moderate levels of nonmixing can induce significant bias, we examined tagging data for two size ranges of fish to determine if the well-mixed assumption was violated. We suggest that examining spatial patterns of recaptures should be a routine part of analyzing tagging data from multiyear studies. For the striped bass data, the analysis showed little evidence of assumption violation, but in some cases the power of the test was probably low because the number of recaptures was small.}, number={5}, journal={TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY}, author={Latour, RJ and Hoenig, JM and Olney, JE and Pollock, KH}, year={2001}, month={Sep}, pages={848–856} }
 @article{alpizar-jara_brooks_pollock_steffen_pack_norman_2001, title={An eastern wild turkey population dynamics model for Virginia and West Virginia}, volume={65}, ISSN={["0022-541X"]}, DOI={10.2307/3803093}, abstractNote={Hunting can have potentially significant impacts on wild turkey (Meleagris gallopavo) populations. We developed a 2-sex Leslie-type matrix model that predicts wild turkey population size for spring-summer and fall-winter periods to understand the effects of hunting on the dynamics of wild turkey populations in Virginia and West Virginia. A base model incorporates parameters derived from a large-scale radiotelemetry study (n = 1,543 hens radio-tagged) conducted over areas with different fall hunting seasons in Virginia and West Virginia from 1989 to 1994. These data made it possible to evaluate the effects of season length, season timing, and 1- versus 2-sex kills on population growth and future harvests. A sensitivity analysis confirmed that fall hunting has the strongest negative effect on the population growth rate. For the range of parameters explored, population growth rate appeared to decrease linearly with increases in fall hunting. Also, the proportion of males in the population was more sensitive to fall rather than spring hunting. These results were invariant to a wide variety of different model calibrations.}, number={3}, journal={JOURNAL OF WILDLIFE MANAGEMENT}, author={Alpizar-Jara, R and Brooks, EN and Pollock, KH and Steffen, DE and Pack, JC and Norman, GW}, year={2001}, month={Jul}, pages={415–424} }
 @article{latour_hoenig_olney_pollock_2001, title={Diagnostics for multiyear tagging models with application to Atlantic striped bass (Morone saxatilis)}, volume={58}, ISSN={["1205-7533"]}, DOI={10.1139/cjfas-58-9-1716}, number={9}, journal={CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES}, author={Latour, RJ and Hoenig, JM and Olney, JE and Pollock, KH}, year={2001}, month={Sep}, pages={1716–1726} }
 @article{gerig_pollock_2001, title={Don Williams Hayne - Obituary}, volume={26}, number={2}, journal={Fisheries}, author={Gerig, T. and Pollock, K.}, year={2001}, pages={34} }
 @article{gerig_pollock_2001, title={Ecologist and biometrician - Don William Hayne - 1911-2000}, volume={29}, number={1}, journal={Wildlife Society Bulletin}, author={Gerig, T. and Pollock, K.}, year={2001}, pages={394–395} }
 @article{latour_pollock_wenner_hoenig_2001, title={Estimates of fishing and natural mortality for subadult red drum in South Carolina waters}, volume={21}, ISSN={["1548-8675"]}, DOI={10.1577/1548-8675(2001)021<0733:EOFANM>2.0.CO;2}, abstractNote={Subadult red drum Sciaenops ocellatus were sampled in Charleston, South Carolina, from 1991 to 1999. Tagged individuals were subjected to either live recapture and release by research biologists or harvest and subsequent tag recovery by recreational anglers. Tag recovery data aggregated into 4-month periods were analyzed using Brownie models that were parameterized in terms of fishing effort and instantaneous rates of fishing (F) and natural (M) mortality. Within-year estimates of fishing effort were calculated from the U.S. National Marine Fisheries Service's Marine Recreational Fisheries Statistics Survey and adjusted to reflect a 4-month harvesting period. The level of annual effort appeared stable over all years and was held constant for all analyses; however, the within-year seasonal pattern of fishing effort varied substantially. Estimates of F and M depended heavily on the values used for the tag-reporting rate (λ) and the tag-retention and immediate survival rate (φ). For age-1 fish, values of φ·λ ranging from 0.8 to 0.3 produced F values between 0.27 and 0.71 and M values between 0.88 and 0.44, respectively. For age-2 fish, similar values for φ·λ yielded F values of 0.35–0.92 and M values of 1.37–0.83, respectively. The natural mortality estimates for age-2 fish also reflect emigration from the bay and estuarine systems to the coastal ocean.}, number={4}, journal={NORTH AMERICAN JOURNAL OF FISHERIES MANAGEMENT}, author={Latour, RJ and Pollock, KH and Wenner, CA and Hoenig, JM}, year={2001}, month={Nov}, pages={733–744} }
 @article{nasution_brownie_pollock_bennetts_2001, title={Estimating survival from joint analysis of resighting and radiotelemetry capture-recapture data for wild animals}, volume={6}, ISSN={["1085-7117"]}, DOI={10.1198/10857110152946839}, number={4}, journal={JOURNAL OF AGRICULTURAL BIOLOGICAL AND ENVIRONMENTAL STATISTICS}, author={Nasution, MD and Brownie, C and Pollock, KH and Bennetts, RE}, year={2001}, month={Dec}, pages={461–478} }
 @article{boulinier_nichols_hines_sauer_flather_pollock_2001, title={Forest fragmentation and bird community dynamics: Inference at regional scales}, volume={82}, number={4}, journal={Ecology (Brooklyn, New York, N.Y.)}, author={Boulinier, T. and Nichols, J. D. and Hines, J. E. and Sauer, J. R. and Flather, C. H. and Pollock, K. H.}, year={2001}, pages={1159–1169} }
 @article{pollock_2001, title={George Seber: A statistical ecology pioneer and scientist par excellence}, volume={6}, ISSN={["1537-2693"]}, DOI={10.1198/108571101750524508}, number={2}, journal={JOURNAL OF AGRICULTURAL BIOLOGICAL AND ENVIRONMENTAL STATISTICS}, author={Pollock, KH}, year={2001}, month={Jun}, pages={152–157} }
 @article{norris_pollock_2001, title={Nonparametric MLE incorporation of heterogeneity and model testing into premarked cohort studies}, volume={8}, ISSN={["1573-3009"]}, DOI={10.1023/A:1009697731573}, number={1}, journal={ENVIRONMENTAL AND ECOLOGICAL STATISTICS}, author={Norris, JL and Pollock, KH}, year={2001}, month={Mar}, pages={21–32} }
 @article{coffman_nichols_pollock_2001, title={Population dynamics of Microtus pennsylvanicus in corridor-linked patches}, volume={93}, ISSN={["1600-0706"]}, DOI={10.1034/j.1600-0706.2001.930101.x}, abstractNote={Corridors have become a key issue in the discussion of conservation planning; however, few empirical data exist on the use of corridors and their effects on population dynamics. The objective of this replicated, population level, capture-recapture experiment on meadow voles was to estimate and compare population characteristics of voles between (1) corridor-linked fragments, (2) isolated or non-linked fragments, and (3) unfragmented areas. We conducted two field experiments involving 22 600 captures of 5700 individuals. In the first, the maintained corridor study, corridors were maintained at the time of fragmentation, and in the second, the constructed corridor study, we constructed corridors between patches that had been fragmented for some period of time. We applied multistate capture-recapture models with the robust design to estimate adult movement and survival rates, population size, temporal variation in population size, recruitment, and juvenile survival rates. Movement rates increased to a greater extent on constructed corridor-linked grids than on the unfragmented or non-linked fragmented grids between the pre- and post-treatment periods. We found significant differences in local survival on the treated (corridor-linked) grids compared to survival on the fragmented and unfragmented grids between the pre- and post-treatment periods. We found no clear pattern of treatment effects on population size or recruitment in either study. However, in both studies, we found that unfragmented grids were more stable than the fragmented grids based on lower temporal variability in population size. To our knowledge, this is the first experimental study demonstrating that corridors constructed between existing fragmented populations can indeed cause increases in movement and associated changes in demography, supporting the use of constructed corridors for this purpose in conservation biology.}, number={1}, journal={OIKOS}, author={Coffman, CJ and Nichols, JD and Pollock, KH}, year={2001}, month={Apr}, pages={3–21} }
 @article{norman_pack_taylor_steffen_pollock_2001, title={Reproduction of eastern wild turkeys in Virginia and West Virginia}, volume={65}, ISSN={["1937-2817"]}, DOI={10.2307/3803269}, abstractNote={Knowledge of reproductive parameters and assessment of the relative importance of factors affecting reproductive success are essential for effective management of eastern wild turkeys (Meleagris gallopavo silvestris). We determined reproductive parameters of 599 radiomarked hens (293 for >1 yr), and the effects of age, year, region, condition (winter weight), incubation chronology (periods), land-ownership, and weather on their reproductive success in 3 Appalachian Mountain regions of Virginia and West Virginia. Average first nest incubation initiation was May 5 ± 0.6 days (x ± SE, n = 629). Production rate (poults alive 4 weeks post batch/female alive 1 Apr) averaged 1.46 ± 0.09 (n = 863). Nesting rates were lower than studies in other regions and may be limiting reproduction. Production rates increased with age (juv: 0.47 ± 0.14, 2+: 1.40 ± 0.14, 3+ 2.55 ± 0.25), but did not differ among regions, years, or weight classes of winter-trapped juvenile or adult hens. Reproduction was evaluated by quintiles (periods) of the first incubation dates by year. Hens that began incubation in the second or third periods had higher (>67%) incubation completion rates than other periods (≤50%), but potential production rates (poults alive 4 weeks post hatch/female completing incubation) were not different among incubation periods. Potential production rates were higher on private lands (3.93 ± 0.30) than public lands (2.67 ± 0.43). Nest incubation dates in Virginia were correlated with mean March temperatures (p = -0.53) and snow depth (p = 0.52). Managers should cautiously implement or increase fall either-sex hunting seasons in populations with survival and production rates similar to those we studied. Older hens play a critical role in reproductive success in the Appalachians. In areas with fall either-sex hunting, season timing and length that reduce adult vulnerability may lessen hunting impacts on reproduction and population growth.}, number={1}, journal={JOURNAL OF WILDLIFE MANAGEMENT}, author={Norman, GW and Pack, JC and Taylor, CI and Steffen, DE and Pollock, KH}, year={2001}, month={Jan}, pages={1–9} }
 @article{pollock_hoenig_hearn_calingaert_2001, title={Tag reporting rate estimation: 1. An evaluation of the high-reward tagging method}, volume={21}, ISSN={["1548-8675"]}, DOI={10.1577/1548-8675(2001)021<0521:TRREAE>2.0.CO;2}, abstractNote={Tag-return models can be used to estimate survival rates and tag recovery rates. The additional knowledge of an estimated tag reporting rate allows one to separate total mortality into fishing and natural mortality rates. This paper examines the use of high-reward tags in tagging studies. We find that many of the problems encountered in tagging studies can be avoided if tagged animals are released in small batches in as many locations as possible rather than in large batches at a few locations. Often, the use of substantial monetary rewards for the return of standard tags may be justified as cost effective because of the higher tag return rates they induce. The high-reward tagging method is an important method for estimating the tag reporting rate for standard tags. For this method it is assumed that high-reward tags are reported 100% of the time. This assumption is investigated. Other assumptions of the method are also considered, and particular attention is paid to whether the reporting rate of standard tags may change when a high-reward tagging study is initiated. This is of particular concern in cases in which standard tags are used for all study years and high-reward tags are only used in some subset of the study years. If the natural mortality rate is assumed to be constant over all years, then fishing and natural mortality together with two tag reporting rates can be estimated. Simulation analysis shows that fishing mortality estimates are unbiased in this case but have significantly higher coefficients of variation in the years without high-reward tags. Natural mortality estimates are unbiased and reasonably efficient, but this is crucially dependent on the assumption that natural mortality is constant over time. We make detailed recommendations for improving the design of reward tagging studies in general.}, number={3}, journal={NORTH AMERICAN JOURNAL OF FISHERIES MANAGEMENT}, author={Pollock, KH and Hoenig, JM and Hearn, WS and Calingaert, B}, year={2001}, month={Aug}, pages={521–532} }
 @article{hightower_jackson_pollock_2001, title={Use of telemetry methods to estimate natural and fishing mortality of striped bass in Lake Gaston, North Carolina}, volume={130}, ISSN={["1548-8659"]}, DOI={10.1577/1548-8659(2001)130<0557:UOTMTE>2.0.CO;2}, abstractNote={Natural mortality can substantially affect fish population dynamics, but the rate is difficult to estimate because natural deaths are rarely observed and it is difficult to separate the effects of natural and fishing mortality on abundance. We developed a new telemetry approach for estimating natural and fishing mortality rates and applied it to the population of striped bass Morone saxatilis in Lake Gaston, North Carolina and Virginia. Our analyses were based on a sample size of 51 telemetered striped bass that were known to be alive and in Lake Gaston at least 1 month after capture and surgery. Relocations of live fish and fish that died of natural causes were used to estimate natural and fishing mortality rates and the probability of relocating telemetered fish. Fishing mortality rates varied seasonally, but few natural deaths were observed, so the best model incorporated a constant annual instantaneous natural mortality rate (M; ±SE) of 0.14 ± 0.02. With the uncertainty in model selection accounted for, the average annual M was 0.16 ± 0.04 for 1997 and 0.12 ± 0.04 for 1998. Estimated annual fishing mortality rates (F) were 0.74 ± 0.13 for 1997 and 0.34 ± 0.18 for 1998. This telemetry approach for estimating mortality rates does not rely on angler reporting of tagged fish. The relative standard errors for M (24–33%) were comparable to those obtained from traditional tagging methods with large sample sizes. This approach is most applicable in closed systems, where fishing mortality estimates are not biased by emigration. A high relocation probability is critical to reliably establishing seasonal changes in mortality.}, number={4}, journal={TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY}, author={Hightower, JE and Jackson, JR and Pollock, KH}, year={2001}, month={Jul}, pages={557–567} }
 @article{pollock_2000, title={Capture-recapture models}, volume={95}, DOI={10.1080/01621459.2000.10473926}, abstractNote={Here I briefly review capture-recapture models as they apply to estimation of demographic parameters (e.g., population size, survival, recruitment, emigration, and immigration) for wild animal populations. These models are now also widely used in a variety of other applications, such as the census undercount, incidence of disease, criminality, homelessness, and computer bugs (see Pollock 1991 for many references). Although they have their historical roots in the sixteenth century, capture-recapture models are basically a twentieth century phenomenon. The papers by Petersen and Lincoln (Seber 1982) from late last century and early this century represent early attempts by biologists to use capture-recapture methods. Later, as statistical inference took its modern form and provided powerful tools such as maximum likelihood methods, biometricians became involved. There has been an explosion of research that still seems to be accelerating at the century’s end. Fortunately, most of the research is still rooted in the need to solve biological questions. Section 2 reviews closed models; Section 3, open models; and Section 4, combined models. I conclude the article with my views on fruitful current and future research thrusts and how the pace of change is affecting them.}, number={449}, journal={Journal of the American Statistical Association}, author={Pollock, K. H.}, year={2000}, pages={293–296} }
 @article{zehfuss_hightower_pollock_1999, title={Abundance of Gulf sturgeon in the Apalachicola River, Florida}, volume={128}, ISSN={["1548-8659"]}, DOI={10.1577/1548-8659(1999)128<0130:AOGSIT>2.0.CO;2}, abstractNote={Gulf sturgeon Acipenser oxyrinchus desotoi a subspecies of Atlantic sturgeon A. oxyrinchus were once abundant in coastal rivers of the eastern Gulf of Mexico but have declined substantially due to habitat loss and overexploitation. Because relatively little is known about their population status in the Apalachicola River, Florida, we used capture–recapture data collected during 1982–1991 to assess the population of Gulf sturgeon at the Jim Woodruff Lock and Dam, which limits upstream migration. We estimated that about 100 fish greater than 45 cm total length were present below the dam, although the estimates were biased to an unknown degree because of violations of capture–recapture model assumptions. To obtain a less biased estimate, we conducted an intensive 10-week capture–recapture experiment in 1993 that accounted for most of the assumption violations. We also used radiotelemetry to test the assumption that the population remained closed to immigration and emigration during sampling. The 1993 results also indicated a population of about 100 Gulf sturgeon below the dam; however, movement in and out of the sampling area occurred, so the population at the dam was not closed. Using simulation, we found that Jolly–Seber and Schnabel capture–recapture models were generally unbiased when fish had a high probability of returning to the study area after temporary emigration. However, when fish had a low probability of returning to the study area after temporary emigration, substantial bias occurred in both models. Length composition data from 1982 to 1991 and for 1993 suggested that low recruitment may account for the failure of the population to rebuild. We recommend identifying all areas of concentration of Gulf sturgeon in the Apalachicola River and developing a standardized sampling program for monitoring this threatened species.}, number={1}, journal={TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY}, author={Zehfuss, KP and Hightower, JE and Pollock, KH}, year={1999}, month={Jan}, pages={130–143} }
 @article{hines_boulinier_nichols_sauer_pollock_1999, title={COMDYN: Software to study the dynamics of animal communities using a capture-recapture approach}, volume={46}, DOI={10.1080/00063659909477247}, abstractNote={COMDYN is a set of programs developed for estimation of parameters associated with community dynamics using count data from two locations or time periods. It is Internet-based, allowing remote users either to input their own data, or to use data from the North American Breeding Bird Survey for analysis. COMDYN allows probability of detection to vary among species and among locations and time periods. The basic estimator for species richness underlying all estimators is the jackknife estimator proposed by Burnham and Overton. Estimators are presented for quantities associated with temporal change in species richness, including rate of change in species richness over time, local extinction probability, local species turnover and number of local colonizing species. Estimators are also presented for quantities associated with spatial variation in species richness, including relative richness at two locations and proportion of species present in one location that are also present at a second location. Application of the estimators to species richness estimation has been previously described and justified. The potential applications of these programs are discussed.}, number={1999}, journal={Bird Study}, author={Hines, J. E. and Boulinier, T. and Nichols, J. D. and Sauer, J. R. and Pollock, K. H.}, year={1999}, pages={209–217} }
 @article{ash_pollock_1999, title={Clearcuts, salamanders, and field studies}, volume={13}, ISSN={["1523-1739"]}, DOI={10.1046/j.1523-1739.1999.98257.x}, abstractNote={Conservation BiologyVolume 13, Issue 1 p. 206-208 Clearcuts, Salamanders, and Field Studies Andrew N. Ash, Andrew N. Ash Department of Biology, University of North Carolina, Pembroke, P.O. Box 1510, Pembroke, NC 28372–1520, U.S.A., email AASH@nat.uncp.eduSearch for more papers by this authorKenneth H. Pollock, Kenneth H. Pollock Department of Statistics, North Carolina State University, Box 8203, Raleigh, NC 27695–8203, U.S.A.Search for more papers by this author Andrew N. Ash, Andrew N. Ash Department of Biology, University of North Carolina, Pembroke, P.O. Box 1510, Pembroke, NC 28372–1520, U.S.A., email AASH@nat.uncp.eduSearch for more papers by this authorKenneth H. Pollock, Kenneth H. Pollock Department of Statistics, North Carolina State University, Box 8203, Raleigh, NC 27695–8203, U.S.A.Search for more papers by this author First published: 24 December 2001 https://doi.org/10.1046/j.1523-1739.1999.98257.xCitations: 7AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume13, Issue1February 1999Pages 206-208 RelatedInformation}, number={1}, journal={CONSERVATION BIOLOGY}, author={Ash, AN and Pollock, KH}, year={1999}, month={Feb}, pages={206–208} }
 @inbook{alpizar-jara_pollock_1999, title={Combining line transect and capture-recapture for mark-resighting studies}, booktitle={Marine mammal survey and assessment methods: Proceedings of the Symposium on Surveys, Status & Trends of Marine Mammal Populations: Seattle, Washington, USA, 25-27 February 1998}, publisher={Rotterdam; Brookfield, VT: Balkema}, author={Alpizar-Jara, R. and Pollock, K. H.}, year={1999}, pages={99–114} }
 @article{pack_norman_taylor_steffen_swanson_pollock_alpizar-jara_1999, title={Effects of fall hunting on wild turkey populations in Virginia and West Virginia}, volume={63}, ISSN={["1937-2817"]}, DOI={10.2307/3802811}, abstractNote={The effect of fall either-sex hunting on eastern wild turkey (Meleagris gallopavo silvestris) populations is a common concern of wildlife agencies. We examined the effect of fall either-sex hunting on survival of radiotagged female wild turkeys from 1989 to 1994 in Virginia and West Virginia. We tested the hypothesis that survival of female wild turkeys did not differ among areas closed to fall hunting, open to a 4-week fall season, or open to an. 8- or 9-week fall hunting season. Mean annual survival rates were higher in the area closed to fall hunting than in regions where fall hunting occurred (P = 0.05). Mean annual survival rates varied within years (P ≤ 0.05). Differences in annual survival rate among areas were attributed to legal hunting (P ≤ 0.01). Poaching was a major mortality factor. Juvenile, yearling, and adult hens had similar survival rates in the areas closed to fall hunting and with 4 weeks of fall hunting (P = 0.39), but survival rates of juveniles were lower (P = 0.03) than those of yearling and adult females in the area with an 8-9-week fall hunting season. Harvest rates of female turkeys averaged 4.3% in the 4-week fall hunted area and 12.3% on the 8-9-week fall hunted area. Higher harvests were achieved on the study area opened only to spring hunting than the combined fall-spring harvests on the other study areas. Total harvest was negatively associated with survival (r s =- 0.90, P = 0.04) on the 8-9-week fall hunted area and positively associated with survival (r s = 0.90, P = 0.04) in the area closed to fall hunting. Spring gobbler-only hunting is suggested for maximum growth in a wild turkey population. Guidelines are presented for fall harvest programs.}, number={3}, journal={JOURNAL OF WILDLIFE MANAGEMENT}, author={Pack, JC and Norman, GW and Taylor, CI and Steffen, DE and Swanson, DA and Pollock, KH and Alpizar-Jara, R}, year={1999}, month={Jul}, pages={964–975} }
 @article{tsai_pollock_brownie_1999, title={Effects of violation of assumptions for survival analysis methods in radiotelemetry studies}, volume={63}, number={4}, journal={Journal of Wildlife Management}, author={Tsai, K. and Pollock, K. H. and Brownie, C.}, year={1999}, pages={1369–1375} }
 @article{tsai_brownie_nychka_pollock_1999, title={Smoothing hazard functions for telemetry survival data in wildlife studies}, volume={46}, number={1999}, journal={Bird Study}, author={Tsai, K. and Brownie, C. and Nychka, D. W. and Pollock, K. H.}, year={1999}, pages={47–54} }
 @article{gould_stefanski_pollock_1999, title={Use of simulation-extrapolation estimation in catch-effort analyses}, volume={56}, ISSN={["0706-652X"]}, DOI={10.1139/cjfas-56-7-1234}, number={7}, journal={CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES}, author={Gould, WR and Stefanski, LA and Pollock, KH}, year={1999}, month={Jul}, pages={1234–1240} }
 @article{chen_pollock_hoenig_1998, title={Combining change-in-ratio, index-removal, and removal models for estimating population size}, volume={54}, ISSN={["1541-0420"]}, DOI={10.2307/2533836}, abstractNote={There are three methods that can be used to estimate population size when survey data are collected just before and just after two or more known harvests: change-in-ratio, index-removal, and catch-effort (removal) methods. In this paper, we introduce a methodology that combines all three methods. We begin by modeling the survey and removal processes as a Poisson point process and a linear death process, respectively, and then we combine the two processes. The completedata likelihood can be factored into three parts: the general likelihood function of the index-removal method, the general likelihood function of the change-in-ratio method, and the general likelihood function of the catch-effort method. We compute the maximum likelihood estimates using the Powell search algorithm. Monte Carlo simulations are used to demonstrate that the estimates from combining change-in-ratio, index-removal, and catch-effort methods are more precise than the estimates based on combining any two of them or only using a single method. An example based on snow crab data is presented to illustrate the methodology.}, number={3}, journal={BIOMETRICS}, author={Chen, CL and Pollock, KH and Hoenig, JM}, year={1998}, month={Sep}, pages={815–827} }
 @article{nichols_boulinier_hines_pollock_sauer_1998, title={Estimating rates of local species extinction, colonization, and turnover in animal communities}, volume={8}, DOI={10.2307/2640974}, number={4}, journal={Ecological Applications}, author={Nichols, J. D. and Boulinier, T. and Hines, J. E. and Pollock, K. H. and Sauer, J. R.}, year={1998}, pages={1213–1225} }
 @article{boulinier_nichols_sauer_hines_pollock_1998, title={Estimating species richness: The importance of heterogeneity in species detectability}, volume={79}, ISSN={["1939-9170"]}, DOI={10.2307/176597}, number={3}, journal={ECOLOGY}, author={Boulinier, T and Nichols, JD and Sauer, JR and Hines, JE and Pollock, KH}, year={1998}, month={Apr}, pages={1018–1028} }
 @article{haines_pollock_1998, title={Estimating the number of active and successful bald eagle nests: an application of the dual frame method}, volume={5}, ISSN={["1352-8505"]}, DOI={10.1023/A:1009673403664}, number={3}, journal={ENVIRONMENTAL AND ECOLOGICAL STATISTICS}, author={Haines, DE and Pollock, KH}, year={1998}, month={Sep}, pages={245–256} }
 @article{brooks_pollock_hoenig_hearn_1998, title={Estimation of fishing and natural mortality from tagging studies an fisheries with two user groups}, volume={55}, ISSN={["1205-7533"]}, DOI={10.1139/cjfas-55-9-2001}, number={9}, journal={CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES}, author={Brooks, EN and Pollock, KH and Hoenig, JM and Hearn, WS}, year={1998}, month={Sep}, pages={2001–2010} }
 @article{boulinier_nichols_hines_sauer_flather_pollock_1998, title={Higher temporal variability of forest breeding bird communities in fragmented landscapes}, volume={95}, ISSN={["0027-8424"]}, DOI={10.1073/pnas.95.13.7497}, abstractNote={Understanding the relationship between animal community dynamics and landscape structure has become a priority for biodiversity conservation. In particular, predicting the effects of habitat destruction that confine species to networks of small patches is an important prerequisite to conservation plan development. Theoretical models that predict the occurrence of species in fragmented landscapes, and relationships between stability and diversity do exist. However, reliable empirical investigations of the dynamics of biodiversity have been prevented by differences in species detection probabilities among landscapes. Using long-term data sampled at a large spatial scale in conjunction with a capture-recapture approach, we developed estimates of parameters of community changes over a 22-year period for forest breeding birds in selected areas of the eastern United States. We show that forest fragmentation was associated not only with a reduced number of forest bird species, but also with increased temporal variability in the number of species. This higher temporal variability was associated with higher local extinction and turnover rates. These results have major conservation implications. Moreover, the approach used provides a practical tool for the study of the dynamics of biodiversity.}, number={13}, journal={PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA}, author={Boulinier, T and Nichols, JD and Hines, JE and Sauer, JR and Flather, CH and Pollock, KH}, year={1998}, month={Jun}, pages={7497–7501} }
 @article{nichols_boulinier_hines_pollock_sauer_1998, title={Inference methods for spatial variation in species richness and community composition when not all species are detected}, volume={12}, ISSN={["1523-1739"]}, DOI={10.1046/j.1523-1739.1998.97331.x}, number={6}, journal={CONSERVATION BIOLOGY}, author={Nichols, JD and Boulinier, T and Hines, JE and Pollock, KH and Sauer, JR}, year={1998}, month={Dec}, pages={1390–1398} }
 @article{hoenig_barrowman_pollock_brooks_hearn_polacheck_1998, title={Models for tagging data that allow for incomplete mixing of newly tagged animals}, volume={55}, ISSN={["1205-7533"]}, DOI={10.1139/cjfas-55-6-1477}, number={6}, journal={CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES}, author={Hoenig, JM and Barrowman, NJ and Pollock, KH and Brooks, EN and Hearn, WS and Polacheck, T}, year={1998}, month={Jun}, pages={1477–1483} }
 @article{hoenig_barrowman_hearn_pollock_1998, title={Multiyear tagging studies incorporating fishing effort data}, volume={55}, ISSN={["1205-7533"]}, DOI={10.1139/cjfas-55-6-1466}, number={6}, journal={CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES}, author={Hoenig, JM and Barrowman, NJ and Hearn, WS and Pollock, KH}, year={1998}, month={Jun}, pages={1466–1476} }
 @article{norris_pollock_1998, title={Non-parametric MLE for Poisson species abundance models allowing for heterogeneity between species}, volume={5}, ISSN={["1352-8505"]}, DOI={10.1023/A:1009659922745}, number={4}, journal={ENVIRONMENTAL AND ECOLOGICAL STATISTICS}, author={Norris, JL and Pollock, KH}, year={1998}, month={Dec}, pages={391–402} }
 @article{hearn_pollock_brooks_1998, title={Pre- and post-season tagging models: estimation of reporting rate and fishing and natural mortality rates}, volume={55}, ISSN={["1205-7533"]}, DOI={10.1139/cjfas-55-1-199}, number={1}, journal={CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES}, author={Hearn, WS and Pollock, KH and Brooks, EN}, year={1998}, month={Jan}, pages={199–205} }
 @article{pollock_hoenig_jones_robson_greene_1997, title={Catch rate estimation for roving and access point surveys}, volume={17}, number={1}, journal={North American Journal of Fisheries Management}, author={Pollock, K. H. and Hoenig, J. M. and Jones, C. M. and Robson, D. S. and Greene, C. J.}, year={1997}, pages={11} }
 @article{gould_pollock_1997, title={Catch-effort maximum likelihood estimation of important population parameters}, volume={54}, ISSN={["1205-7533"]}, DOI={10.1139/cjfas-54-4-890}, number={4}, journal={CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES}, author={Gould, WR and Pollock, KH}, year={1997}, month={Apr}, pages={890–897} }
 @article{gould_stefanski_pollock_1997, title={Effects of measurement error on catch-effort estimation}, volume={54}, ISSN={["1205-7533"]}, DOI={10.1139/cjfas-54-4-898}, number={4}, journal={CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES}, author={Gould, WR and Stefanski, LA and Pollock, KH}, year={1997}, month={Apr}, pages={898–906} }
 @article{brownie_hines_nichols_pollock_hestbeck_1993, title={CAPTURE-RECAPTURE STUDIES FOR MULTIPLE STRATA INCLUDING NON-MARKOVIAN TRANSITIONS}, volume={49}, ISSN={["0006-341X"]}, DOI={10.2307/2532259}, abstractNote={We consider capture-recapture studies where release and recapture data are available from each of a number of strata on every capture occasion. Strata may, for example, be geographic locations or physiological states. Movement of animals among strata occurs with unknown probabilities, and estimation of these unknown transition probabilities is the objective. We describe a computer routine for carrying out the analysis under a model that assumes Markovian transitions and under reducedparameter versions of this model. We also introduce models that relax the Markovian assumption and allow memory to operate (i.e., allow dependence of the transition probabilities on the previous state). For these models, we suggest an analysis based on a conditional likelihood approach. Methods are illustrated with data from a large study on Canada geese (Branta canadensis) banded in three geographic regions. The assumption of Markovian transitions is rejected convincingly for these data, emphasizing the importance of the more general models that allow memory.}, number={4}, journal={BIOMETRICS}, author={BROWNIE, C and HINES, JE and NICHOLS, JD and POLLOCK, KH and HESTBECK, JB}, year={1993}, month={Dec}, pages={1173–1187} }
 @article{pollock_nichols_brownie_hines_1990, title={Statistical-inference for capture-recapture experiments}, number={107}, journal={Wildlife Monographs}, author={Pollock, K. H. and Nichols, J. D. and Brownie, C. and Hines, J. E.}, year={1990}, pages={1–97} }
 @article{pollock_winterstein_bunck_curtis_1989, title={SURVIVAL ANALYSIS IN TELEMETRY STUDIES - THE STAGGERED ENTRY DESIGN}, volume={53}, ISSN={["0022-541X"]}, DOI={10.2307/3801296}, abstractNote={The estimation of survival distributions for radio-tagged animals is important to wildlife ecologists. Allowance must be made for animals being lost (or censored) due to radio failure, radio loss, or emigration of the animal from the study area. The Kaplan-Meier procedure (Kaplan and Meier 1958), widely used in medical studies subject to censoring, can be applied to this problem. We developed a simple modification of the Kaplan-Meier procedure that allows for new animals to be added after the study has begun. We present 2 examples using telemetry data collected from northern bobwhite quail (Colinus virginianus) to show the simplicity and utility of the Kaplan-Meier procedure and its modifications. The log rank test used to compare 2 survival distributions can also be modified to allow for additions during the study. Simple computer programs that can be run on a personal computer are available from the authors. J. WILDL. MANAGE. 53(1):7-15 Radio-tagged animals are used to study survival. Present techniques for analyzing data from these studies assume that each survival event (typically an animal surviving a day) is independent and has a constant probability over all animals and all periods (Trent and Rongstad 1974, Bart and Robson 1982, Heisey and Fuller 1985). We believe these assumptions are often unrealistic and restrictive. White (1983) generalized discrete approaches using the same framework as that of band return models (Brownie et al. 1985) and he developed a flexible computer program (SURVIV) for use with his approach. Heisey and Fuller (1985) generalized the Trent and Rongstad (1974) approach to allow mortality from different causes (e.g., predation, starvation) and developed a microcomputer program called MICROMORT. Typically an animal's exact survival time (at least to within 1-2 days) is known unless that survival time is right censored (i.e., only known to be greater than some value). Pollock (1984) and Pollock et al. (1989) suggested a useful approach based on continuous survival models allowing right censoring that is widely used in medicine and engineering (Kalbfleisch and Prentice 1980, Cox and Oakes 1984) and provided examples of the Kaplan-Meier procedure. The Kaplan-Meier procedure does not require specification of a particular parametric continuous distribution; e.g., the exponential or Weibull. Related ecological papers using survival methods include Muenchow (1986), Pyke and Thompson (1986), Kurzejeski et al. (1987), and White et al. (1987). We present a simple description of the Kaplan-Meier procedure with an example using northern bobwhite quail survival data collected by PDC. We then generalize the Kaplan-Meier procedure to allow gradual (or staggered) entry of animals into the study. The calculations are illustrated with an example from the quail data. Finally, we present the log-rank test for comparison of survival distributions (modified for staggered entry of animals) with an example. We also present a discussion of model assumptions and directions for future research. We thank J. D. Nichols and W. L. Link for helpful comments on an earlier draft of this paper. We acknowledge G. C. White and D. M. Heisey for their helpful reviews that improved the final version. THE KAPLAN-MEIER OR PRODUCT LIMIT PROCEDURE The Kaplan-Meier or product limit estimator was developed by Kaplan and Meier (1958) and is d scussed by Cox and Oakes (1984:48) and Kalbfleisch and Prentice (1980:13). The survival function (S[t]) is the probability of an arbitrary animal in a population surviving t units of time from the beginning of the study. A nonparametric estimator of the survival function can be obtained by restricting ourselves to the discrete time points when deaths occur a1, a2, ..., ag. We define r, . . . , rg to be the numbers of an-}, number={1}, journal={JOURNAL OF WILDLIFE MANAGEMENT}, author={POLLOCK, KH and WINTERSTEIN, SR and BUNCK, CM and CURTIS, PD}, year={1989}, month={Jan}, pages={7–15} }