@article{rivera_henderson_lam_hostetter_collazo_bell_2024, title={High-Quality, Chromosome-Level Reference Genomes of the Viviparous Caribbean Skinks Spondylurus nitidus and S. culebrae}, volume={16}, ISSN={["1759-6653"]}, url={https://doi.org/10.1093/gbe/evae079}, DOI={10.1093/gbe/evae079}, abstractNote={Abstract New World mabuyine skinks are a diverse radiation of morphologically cryptic lizards with unique reproductive biologies. Recent studies examining population-level data (morphological, ecological, and genomic) have uncovered novel biodiversity and phenotypes, including the description of dozens of new species and insights into the evolution of their highly complex placental structures. Beyond the potential for this diverse group to serve as a model for the evolution of viviparity in lizards, much of the taxonomic diversity is concentrated in regions experiencing increasing environmental instability from climate and anthropogenic change. Consequently, a better understanding of genome structure and diversity will be an important tool in the adaptive management and conservation of this group. Skinks endemic to Caribbean islands are particularly vulnerable to global change with several species already considered likely extinct and several remaining species either endangered or threatened. Combining PacBio long-read sequencing, Hi-C, and RNAseq data, here we present the first genomic resources for this group by describing new chromosome-level reference genomes for the Puerto Rican Skink Spondylurus nitidus and the Culebra Skink S. culebrae. Results indicate two high quality genomes, both ∼1.4 Gb, assembled nearly telomere to telomere with complete mitochondrion assembly and annotation.}, number={5}, journal={GENOME BIOLOGY AND EVOLUTION}, author={Rivera, Danielle and Henderson, James B. and Lam, Athena W. and Hostetter, Nathan J. and Collazo, Jaime A. and Bell, Rayna C.}, editor={Zhou, QiEditor}, year={2024}, month={May} }
 @article{ruzi_youngsteadt_cherveny_kettenbach_levenson_carley_collazo_irwin_2023, title={Bee species richness through time in an urbanizing landscape of the southeastern <scp>United States}, volume={30}, ISSN={1354-1013 1365-2486}, url={http://dx.doi.org/10.1111/gcb.17060}, DOI={10.1111/gcb.17060}, abstractNote={Abstract}, number={1}, journal={Global Change Biology}, publisher={Wiley}, author={Ruzi, Selina A. and Youngsteadt, Elsa and Cherveny, April Hamblin and Kettenbach, Jessica and Levenson, Hannah K. and Carley, Danesha Seth and Collazo, Jaime A. and Irwin, Rebecca E.}, year={2023}, month={Dec} }
 @misc{briggs_baranski_munzer schaetz_garrison_collazo_youngsteadt_2022, title={Estimating bee abundance: can mark-recapture methods validate common sampling protocols?}, volume={53}, ISSN={["1297-9678"]}, DOI={10.1007/s13592-022-00919-4}, abstractNote={Abstract}, number={1}, journal={APIDOLOGIE}, author={Briggs, Emma L. and Baranski, Christopher and Munzer Schaetz, Olivia and Garrison, Gabriela and Collazo, Jaime A. and Youngsteadt, Elsa}, year={2022}, month={Mar} }
 @article{patton_pacifici_collazo_2022, title={Modeling and estimating co-occurrence between the invasive Shiny Cowbird and its Puerto Rican hosts}, volume={5}, ISSN={["1573-1464"]}, DOI={10.1007/s10530-022-02825-3}, journal={BIOLOGICAL INVASIONS}, author={Patton, Philip T. and Pacifici, Krishna and Collazo, Jaime A.}, year={2022}, month={May} }
 @article{campos-cerqueira_terando_murray_collazo_aide_2021, title={Climate change is creating a mismatch between protected areas and suitable habitats for frogs and birds in Puerto Rico}, volume={7}, ISSN={["1572-9710"]}, DOI={10.1007/s10531-021-02258-9}, abstractNote={Abstract}, journal={BIODIVERSITY AND CONSERVATION}, author={Campos-Cerqueira, Marconi and Terando, Adam J. and Murray, Brent A. and Collazo, Jaime A. and Aide, T. Mitchell}, year={2021}, month={Jul} }
 @article{irizarry_collazo_vandermeer_perfecto_2021, title={Coffee plantations, hurricanes and avian resiliency: insights from occupancy, and local colonization and extinction rates in Puerto Rico}, volume={27}, ISSN={["2351-9894"]}, DOI={10.1016/j.gecco.2021.e01579}, abstractNote={Insights on impacts and resiliency of avian species with respect to hurricanes in the Caribbean have largely focused on responses measured in protected habitats. We assessed avian responses in non-protected habitat, specifically shade-restored coffee plantations, because their structural complexity retains many attributes of secondary forests, and may contribute to landscape scale species resiliency. We tallied species richness and estimated occupancy probability of 12 resident avian species, after adjusting for imperfect detection, to assess the impact of hurricane Maria (20 September 2017). For five of those species, we also estimated local colonization and extinction probabilities to assess their prospect of rebounding (resiliency) in the context of two stages of shade restoration. We used survey data collected March-June 2015–2017 (pre-hurricane) and 2018 (post-hurricane) in 58 coffee farms and satellite imagery to assess vegetation structure. Restored farms were grouped into two categories based on time-since-restoration: newly-restored and fully-restored. We predicted that mean percent forest cover in fully-restored farms (~30–40%) would revert to levels in newly-restored farms (<15%), with concomitant changes in occupancy by avian species. As predicted, mean percent forest cover (16.17±4.27%) in fully-restored farms post-hurricane reverted to pre-hurricane levels in newly-restored farms (15.00±5.61%). The loss represented 30–38% relative to the pre-hurricane cover levels. Detections of focal species dropped an average of 41% post-hurricane, with associated reductions in occupancy for 9/11 species. Occupancy of the Puerto Rican Bullfinch and Puerto Rican Spindalis reverted to levels detected in newly-restored plantations prior to the hurricane as predicted. Prospects of rebounding were more likely for species with invariant or increases in colonization probability (e.g., Yellow-faced Grassquit, Northern Mockingbird, Puerto Rican Spindalis). Rebounding for frugivores like the Puerto Rican Bullfinch would be protracted given that colonization rates dropped from 0.56±0.12 (pre-hurricane) to 0.04±0.2 (post-hurricane), regardless of restoration stage. Our work showed that the avian community associated with restored coffee farms exhibited a high degree of ecological resistance as the similarity in species composition before and after the hurricane was 81%, and all 12 focal species continued to occupy farms under both restoration stages. The prospect of the focal species to rebound (resiliency) was species-specific, and in some cases, mediated by their affinity to a particular farm restoration stage. The strength of hurricanes is projected to intensify with global warming. Pockets of undamaged or partially damaged shade-grown or fully-restored coffee plantations may contribute to species resiliency by increasing landscape level habitat redundancy, and facilitate habitat shifts to secure food resources or harbor source populations to colonize recovering, hurricane-damaged habitat tracts.}, journal={GLOBAL ECOLOGY AND CONSERVATION}, author={Irizarry, Amarilys D. and Collazo, Jaime A. and Vandermeer, John and Perfecto, Ivette}, year={2021}, month={Jun} }
 @article{rivera-burgos_collazo_terando_pacifici_2021, title={Linking demographic rates to local environmental conditions: Empirical data to support climate adaptation strategies for Eleutherodactylus frogs}, volume={28}, ISSN={["2351-9894"]}, url={https://doi.org/10.1016/j.gecco.2021.e01624}, DOI={10.1016/j.gecco.2021.e01624}, abstractNote={Conducting managed species translocations and establishing climate change refugia are adaptation strategies to cope with projected consequences of global warming, but successful implementation requires on-the-ground validation of demographic responses to transient climate conditions. Here we estimated the effect of nine abiotic and biotic factors on local occupancy and an index of abundance (few or chorus) for four amphibian species (Eleutherodactylus wightmanae, E. brittoni, E. antillensis, and E. coqui) in Puerto Rico, USA. We also assessed how the same factors influenced reproductive activity of E. coqui and how species responded to hurricane María (20 September 2017). As predicted, occupancy and abundance of E. wightmanae, E. brittoni and E. coqui were positively and strongly influenced by abiotic covariates (e.g., relative humidity) that characterize high elevation, mesic habitats. E. antillensis exhibited the opposite pattern, with highest probabilities (≥0.6) recorded at ≤300 m and with average relative humidity<75%. Biotic covariates (e.g., canopy cover) had a weak influence on both parameters, regardless of species. High probabilities (≥0.9) of detecting an E. coqui chorus and active nests occurred at sites experiencing average relative humidity of>80% and temperature of ≤26 °C. Moderate to high probabilities of detecting a chorus (0.4–0.7) were recorded at sites with average temperatures>26 °C, but no reproductive activity was detected, implying that monitoring abundance alone could misrepresent the capacity of a local population to sustain itself. The possibility underscores the importance of understanding the interplay between local demographic and environmental parameters in the advent of global warming to help guide monitoring and management decisions, especially for high elevation specialists. Hurricanes can inflict marked reductions in population numbers, but impacts vary by location and species. We found that the abundance (chorus) of E. antillensis and E. brittoni increased after the hurricane, but the abundance of the other two species did not differ between years. Lack of impacts was probably mediated by low structural damage to forest tracts (e.g., 9% canopy loss). Our findings help assess habitat suitability in terms of parameters that foster local population growth, which provides a basis for testing spatio-temporal predictions about demographic rates in potential climate refugia and for designing criteria to help guide managed translocations.}, journal={GLOBAL ECOLOGY AND CONSERVATION}, publisher={Elsevier BV}, author={Rivera-Burgos, Ana C. and Collazo, Jaime A. and Terando, Adam J. and Pacifici, Krishna}, year={2021}, month={Aug} }
 @article{pease_pacifici_collazo_2021, title={Survey design optimization for monitoring wildlife communities in areas managed for federally endangered species}, volume={24}, ISSN={["1469-1795"]}, DOI={10.1111/acv.12681}, abstractNote={Abstract}, number={5}, journal={ANIMAL CONSERVATION}, author={Pease, B. S. and Pacifici, K. and Collazo, J. A.}, year={2021}, month={Oct}, pages={756–769} }
 @article{prado_collazo_marand_irwin_2021, title={The influence of floral resources and microclimate on pollinator visitation in an agro-ecosystem}, volume={307}, ISSN={["1873-2305"]}, DOI={10.1016/j.agee.2020.107196}, abstractNote={As agriculture expands to meet the needs of a growing global population, natural ecosystems are threatened by deforestation and habitat fragmentation. Tropical agroforestry systems offer a sustainable alternative to traditional agriculture by providing food for production while also supporting biodiversity and ecosystem services. Previous studies have shown that these systems may even improve crop pollination, but the mechanisms of how these improvements occur are still poorly understood. Using coffee as a focal crop, we explored how microclimatic conditions affected nectar traits (sugar and caffeine concentration) important for pollinator visitation. We also studied how microclimate, floral traits, floral availability at the coffee plant level, availability of floral resources provided by other plant species in the agroecosystem (“neighborhood floral availability”), and the presence of other bees affected the amount of time bees spent foraging on coffee flowers and the proportion of coffee pollen carried on their bodies. We explored these factors using the two dominant coffee species farmed on Puerto Rico, Coffea canephora and C. arabica, under sun and shade management. We found that high nectar sugar concentration and temperature were important predictors of short floral visits (<15s), while increased numbers of bees and open coffee flowers were important predictors of longer floral visits (16–180 seconds). High nectar caffeine concentration was an important predictor of longer visits on C. arabica flowers while the opposite was observed for C. canephora flowers. For both species, high coffee floral availability was the main predicting factor for the proportion of coffee pollen on the bees’ bodies. Surprisingly, neither neighborhood floral availability nor the type of coffee plantation (agroforest/shade or sun) were important predictors of bee visitation. These results suggest non-coffee flowering plants in coffee plantations were neither competitors nor facilitators of coffee plants for pollinators. Additionally, most of the bees surveyed were carrying ≥80 % pollen from one species (C. arabica or C. canephora), likely resulting in little heterospecific pollen deposition between Coffea and non-Coffea flowers. Shade trees in coffee plantations do not detract from pollinator visitation to coffee flowers, suggesting that the provision of multiple ecological and wildlife conservation benefits by shade trees is not in conflict with a grower’s ability to maximize the benefits of insect pollination on fruit production.}, journal={AGRICULTURE ECOSYSTEMS & ENVIRONMENT}, author={Prado, Sara Guiti and Collazo, Jaime A. and Marand, Mariam H. and Irwin, Rebecca E.}, year={2021}, month={Feb} }
 @article{huberman_reich_pacifici_collazo_2020, title={Estimating the drivers of species distributions with opportunistic data using mediation analysis}, volume={11}, ISSN={["2150-8925"]}, url={https://doi.org/10.1002/ecs2.3165}, DOI={10.1002/ecs2.3165}, abstractNote={Abstract}, number={6}, journal={ECOSPHERE}, publisher={Wiley}, author={Huberman, David B. and Reich, Brian J. and Pacifici, Krishna and Collazo, Jaime A.}, year={2020}, month={Jun} }
 @article{gladkikh_collazo_torres-abreu_reyes_molina_2020, title={Factors that influence participation of Puerto Rican coffee farmers in conservation programs}, volume={2}, ISSN={["2578-4854"]}, DOI={10.1111/csp2.172}, abstractNote={Abstract}, number={4}, journal={CONSERVATION SCIENCE AND PRACTICE}, author={Gladkikh, Tatiana M. and Collazo, Jaime A. and Torres-Abreu, Alejandro and Reyes, Angelica M. and Molina, Marysol}, year={2020}, month={Apr} }
 @article{vega-castillo_collazo_puente-rolon_cuevas_2020, title={Influence of Habitat Structure and Prey Abundance on Occupancy and Abundance of Two Anole Ecomorphs, Anolis cristatellus and Anolis krugi, in Secondary Karst Forests in Northern Puerto Rico}, volume={54}, ISSN={["1937-2418"]}, DOI={10.1670/19-009}, abstractNote={Abstract Ecological studies strive to identify factors that explain patterns of species distribution and abundance. In lizards, competition and predation are major forces influencing distribution a...}, number={1}, journal={JOURNAL OF HERPETOLOGY}, author={Vega-Castillo, S. and Collazo, Jaime A. and Puente-Rolon, Alberto R. and Cuevas, Elvira}, year={2020}, month={Jan}, pages={107–117} }
 @article{prado_collazo_stevenson_irwin_2019, title={A comparison of coffee floral traits under two different agricultural practices}, volume={9}, ISSN={2045-2322}, url={http://dx.doi.org/10.1038/s41598-019-43753-y}, DOI={10.1038/s41598-019-43753-y}, abstractNote={Abstract}, number={1}, journal={Scientific Reports}, publisher={Springer Science and Business Media LLC}, author={Prado, Sara Guiti and Collazo, Jaime A. and Stevenson, Philip C. and Irwin, Rebecca E.}, year={2019}, month={May} }
 @article{clement_nichols_collazo_terando_hines_williams_2019, title={Partitioning global change: Assessing the relative importance of changes in climate and land cover for changes in avian distribution}, volume={9}, ISBN={2045-7758}, url={https://doi.org/10.1002/ece3.4890}, DOI={10.1002/ece3.4890}, abstractNote={Abstract}, number={4}, journal={ECOLOGY AND EVOLUTION}, publisher={Wiley}, author={Clement, Matthew J. and Nichols, James D. and Collazo, Jaime A. and Terando, Adam J. and Hines, James E. and Williams, Steven G.}, year={2019}, month={Feb}, pages={1985–2003} }
 @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}, 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{collazo_terando_engman_fackler_kwak_2019, title={Toward a Resilience-Based Conservation Strategy for Wetlands in Puerto Rico: Meeting Challenges Posed by Environmental Change}, volume={39}, ISSN={["1943-6246"]}, url={https://doi.org/10.1007/s13157-018-1080-z}, DOI={10.1007/s13157-018-1080-z}, number={6}, journal={WETLANDS}, publisher={Springer Science and Business Media LLC}, author={Collazo, Jaime A. and Terando, Adam J. and Engman, Augustin C. and Fackler, Paul F. and Kwak, Thomas J.}, year={2019}, month={Dec}, pages={1255–1269} }
 @article{irizarry_collazo_pacifici_reich_battle_2018, title={Avian response to shade-layer restoration in coffee plantations in Puerto Rico}, volume={26}, ISSN={["1526-100X"]}, url={https://doi.org/10.1111/rec.12697}, DOI={10.1111/rec.12697}, abstractNote={Documenting the evolving processes associated with habitat restoration and how long it takes to detect avian demographic responses is crucial to evaluate the success of restoration initiatives and to identify ways to improve their effectiveness. The importance of this endeavor prompted the U.S. Fish and Wildlife Service and the USDA Natural Resources Conservation Service to evaluate their sun‐to‐shade coffee restoration program in Puerto Rico initiated in 2003. We quantified the responses of 12 resident avian species using estimates of local occupancy and extinction probabilities based on surveys conducted in 2015–2017 at 65 restored farms grouped according to time‐since‐initial‐restoration (TSIR): new (2011–2014), intermediate (2007–2010), and old (2003–2006). We also surveyed 40 forest sites, which served as reference sites. Vegetation complexity increased with TSIR, ranging between 35 and 40% forest cover in farms 6–9 years TSIR. Forest specialists (e.g. Loxigilla portoricencis) exhibited highest average occupancy in farms initially classified as intermediate (6–9 years) and old (>10 years), paralleling occupancy in secondary forests. Occupancy of open‐habitat specialists (e.g. Tiaris olivaceus) was more variable, but higher in recently restored farms. Restoring the shade layer has the potential to heighten ecological services derived from forest specialists (e.g. frugivores) without losing the services of many open‐habitat specialists (e.g. insectivores). Annual local extinction probability for forest specialists decreased with increasing habitat complexity, strengthening the potential value of shade restoration as a tool to enhance habitat for avifauna that evolved in forested landscapes.}, number={6}, journal={RESTORATION ECOLOGY}, publisher={Wiley}, author={Irizarry, Amarilys D. and Collazo, Jaime A. and Pacifici, Krishna and Reich, Brian J. and Battle, Kathryn E.}, year={2018}, month={Nov}, pages={1212–1220} }
 @article{yirka_collazo_brian j. o'shea_gerwin_rotenberg_cobb_2018, title={Demographic rates of two southeastern populations of Painted Bunting, 2007-2015}, volume={120}, ISSN={["1938-5129"]}, DOI={10.1650/condor-17-74.1}, abstractNote={ABSTRACT Painted Buntings (Passerina ciris) have been declining in the southeastern United States since the 1970s. A recent demographic assessment highlighted the importance of estimating demographic parameters, which have received little attention to date. The dearth of information is troublesome because attempts to reverse declining trends require a better understanding of the relationship between habitat quality and age- and sex-specific survival and recruitment rates. We used capture–mark–recapture data collected from 2007 to 2015 on Bald Head Island (BHI) and at Hammocks Beach State Park (HBSP) in North Carolina, USA, to estimate local age- and sex-specific annual survival rates and local population size and recruitment rates using programs MARK and LOLASURVIV. Juveniles had lower local survival rates than adults (HBSP: 0.28 ± 0.14 vs. 0.67 ± 0.06; BHI: 0.28 ± 0.04 vs. 0.57 ± 0.02). Local annual survival rates for males on BHI (0.50 ± 0.03) were lower than those for females (0.57 ± 0.02). Age-specific differences were consistent with known differential age-dependent survival skills, and sex-specific differences were consistent with the potential influence of sexual dichromism. Conservative estimates of population size on BHI averaged 101 juveniles and 263 adults annually. Annual in situ reproductive recruitment averaged 28 individuals plus an additional 120 new immigrants, indicating successful reproduction and connectivity with neighboring coastal populations. Local adult survival estimates from our 2 North Carolinian study populations were similar to high-end estimates from across the eastern and western range of the species (∼0.60). Finite observed population growth rate estimates between the BHI population (λ = 1.10) and a South Carolinian population (λ = 0.87) underscore the potential role of differential habitat quality and the importance of information from multiple sites, including nonbreeding grounds, for proper inferences about the status of the species. Reported vital rates provide a stronger foundation on which to base habitat quality as assessed with demographic parameters and to guide Painted Bunting conservation regionally.}, number={2}, journal={CONDOR}, author={Yirka, Liani M. and Collazo, Jaime A. and Brian J. O'Shea and Gerwin, John A. and Rotenberg, James A. and Cobb, David T.}, year={2018}, month={May}, pages={319–329} }
 @article{kornegay_wiewel_collazo_saracco_dinsmore_2018, title={Improving our understanding of demographic monitoring: avian breeding productivity in a tropical dry forest}, volume={89}, ISSN={["1557-9263"]}, DOI={10.1111/jofo.12263}, abstractNote={The ratio of juvenile to adult birds in mist‐net samples is used to monitor avian productivity, but whether it is a “true” estimate of per capita productivity or an index proportional to productivity depends on whether capture probability is not age‐dependent (true estimate) or age difference in capture probability is consistent among years (index). Better understanding of the processes affecting age‐ and year‐specific capture probabilities is needed to advance the application of constant‐effort mist‐netting for monitoring and conservation, particularly in many tropical settings where capture rates are often low. We ranked members of the avian community by capture frequencies, determined if temporary emigration influenced the availability of birds to be captured, and assessed the distribution of birds relative to mist‐nets and the parity between capture‐based productivity estimates and number of fledglings in nest plots in a tropical dry forest in Puerto Rico in 2009 and 2010. Few captures characterized the community of 25 resident species and, when estimable, capture probabilities were low, particularly for juveniles (typically < 0.1). Negative trends in capture probability, temporary emigration, and the distribution of birds suggest that avoidance of mist‐nets influenced capture rates in our study. Increasing mist‐net coverage or moving mist‐nets between sampling periods could increase capture rates. The number of fledglings observed in nest plots (25 ha/plot) did not correlate well with capture‐derived estimates (20 ha/net stations), suggesting the presence of immigrants or failure to find all nests. Our results suggest that indices of breeding productivity from mist‐netting data may track temporal changes in productivity, but such data likely do not reflect “true” productivity in most cases unless age‐specific differences in capture probability are incorporated into estimates. Pilot studies should be conducted to evaluate capture rates and the spatial extent sampled by mist‐nets to improve sampling design and inferences before informing decisions.}, number={3}, journal={JOURNAL OF FIELD ORNITHOLOGY}, author={Kornegay, M. Edye and Wiewel, Amber N. M. and Collazo, Jaime A. and Saracco, James F. and Dinsmore, Stephen J.}, year={2018}, month={Sep}, pages={258–275} }
 @article{yirka_collazo_williams_cobb_2018, title={Persistence-Based Area Prioritization for Conservation: Applying Occupancy and Habitat Threats and Risks Analyses}, volume={9}, ISSN={["1944-687X"]}, DOI={10.3996/112017-JFWM-089}, abstractNote={Abstract}, number={2}, journal={JOURNAL OF FISH AND WILDLIFE MANAGEMENT}, author={Yirka, Liani M. and Collazo, Jaime A. and Williams, Steven G. and Cobb, David T.}, year={2018}, month={Dec}, pages={543–553} }
 @article{prado_collazo_irwin_2018, title={Resurgence of specialized shade coffee cultivation: Effects on pollination services and quality of coffee production}, volume={265}, ISSN={0167-8809}, url={http://dx.doi.org/10.1016/j.agee.2018.07.002}, DOI={10.1016/j.agee.2018.07.002}, abstractNote={Since the early 2000s, there has been a resurgence in shade coffee production on the island of Puerto Rico. The newly restored specialized shade canopy consists of four native tree species, three of which are nitrogen fixers, and is intended to provide 30% shade cover once the trees are matured. Though much is known about the benefits of rustic and traditional shade plantations to coffee production, there is little information available for specialized shade plantations. Here, we investigate the ways in which fruit set, seed predation, bean weight, proportion of peaberries (i.e., malformed fruits), and beverage quality differ between sun and specialized shade plantations of Coffea arabica and Coffea canephora. Additionally, to assess whether coffee plants were pollen limited, we conducted a pollen supplementation experiment in which we compared pollen deposition and berry production on hand-pollinated branches to those of naturally, open-pollinated ones. We found that there was no evidence of pollen limitation on fruit set between sun and specialized shade plantations of C. arabica or C. canephora. We found that specialized shade benefits the proportion of C. arabica fruit set, without compromising bean weight or the proportion of peaberries produced. In comparison, C. canephora showed no improvement in the proportion of fruits set with specialized shade; however, beans from open-pollinated flowers weighed more in specialized shade than sun. Beverage quality was marginally better under shade, and for hand-pollinated flowers. Our results add to the limited body of work investigating the benefits of specialized shade coffee plantations on ecosystem services.}, journal={Agriculture, Ecosystems & Environment}, publisher={Elsevier BV}, author={Prado, Sara Guiti and Collazo, Jaime A. and Irwin, Rebecca E.}, year={2018}, month={Oct}, pages={567–575} }
 @article{bjorndal_bolten_chaloupka_saba_bellini_marcovaldi_santos_wurdig bortolon_meylan_meylan_et al._2017, title={Ecological regime shift drives declining growth rates of sea turtles throughout the West Atlantic}, volume={23}, ISSN={["1365-2486"]}, DOI={10.1111/gcb.13712}, abstractNote={Abstract}, number={11}, journal={GLOBAL CHANGE BIOLOGY}, author={Bjorndal, Karen A. and Bolten, Alan B. and Chaloupka, Milani and Saba, Vincent S. and Bellini, Claudio and Marcovaldi, Maria A. G. and Santos, Armando J. B. and Wurdig Bortolon, Luis Felipe and Meylan, Anne B. and Meylan, Peter A. and et al.}, year={2017}, month={Nov}, pages={4556–4568} }
 @article{pickens_mordecai_drew_alexander-vaughn_keister_morris_collazo_2017, title={Indicator-Driven Conservation Planning Across Terrestrial, Freshwater Aquatic, and Marine Ecosystems of the South Atlantic, USA}, volume={8}, ISSN={["1944-687X"]}, DOI={10.3996/062016-jfwm-044}, abstractNote={Abstract}, number={1}, journal={JOURNAL OF FISH AND WILDLIFE MANAGEMENT}, author={Pickens, Bradley A. and Mordecai, Rua S. and Drew, C. Ashton and Alexander-Vaughn, Louise B. and Keister, Amy S. and Morris, Hilary L. C. and Collazo, Jaime A.}, year={2017}, month={Jun}, pages={219–233} }
 @article{pacifici_reich_miller_gardner_stauffer_singh_mckerrow_collazo_2017, title={Integrating multiple data sources in species distribution modeling: a framework for data fusion}, volume={98}, ISSN={["1939-9170"]}, DOI={10.1002/ecy.1710}, abstractNote={Abstract}, number={3}, journal={ECOLOGY}, author={Pacifici, Krishna and Reich, Brian J. and Miller, David A. W. and Gardner, Beth and Stauffer, Glenn and Singh, Susheela and McKerrow, Alexa and Collazo, Jaime A.}, year={2017}, month={Mar}, pages={840–850} }
 @article{pickens_marcus_carpenter_anderson_taillie_collazo_2017, title={The effect of urban growth on landscape-scale restoration for a fire-dependent songbird}, volume={191}, ISSN={["1095-8630"]}, DOI={10.1016/j.jenvman.2017.01.005}, abstractNote={A landscape-scale perspective on restoration ecology has been advocated, but few studies have informed restoration with landscape metrics or addressed broad-scale threats. Threats such as urban growth may affect restoration effectiveness in a landscape context. Here, we studied longleaf pine savanna in the rapidly urbanizing southeastern United States where a habitat-specialist bird, Bachman's sparrow (Peucaea aestivalis), is closely associated with savanna vegetation structure and frequent fire. Our objectives were to construct a species distribution model for Bachman's sparrow, determine the relationship between fire and urbanization, quantify the urban growth effect (2010-2090), identify potential restoration areas, and determine the interaction between restoration potential and urban growth by 2050. Number of patches, patch size, and isolation metrics were used to evaluate scenarios. The species distribution model was 88% accurate and emphasized multiscale canopy cover characteristics, fire, and percent habitat. Fires were less common <600 m from urban areas, and this fire suppression effect exacerbated urban growth effects. For restoration scenarios, canopy cover reduction by 30% resulted in nearly double the amount of habitat compared to the prescribed fire scenario; canopy cover reduction resulted in larger patch sizes and less patch isolation compared to current conditions. The effect of urban growth on restoration scenarios was unequal. Seventy-four percent of restoration areas from the prescribed fire scenario overlapped with projected urban growth, whereas the canopy cover reduction scenario only overlapped by 9%. We emphasize the benefits of simultaneously considering the effects of urban growth and landscape-scale restoration potential to promote a landscape with greater patch sizes and less isolation.}, journal={JOURNAL OF ENVIRONMENTAL MANAGEMENT}, author={Pickens, Bradley A. and Marcus, Jeffrey F. and Carpenter, John P. and Anderson, Scott and Taillie, Paul J. and Collazo, Jaime A.}, year={2017}, month={Apr}, pages={105–115} }
 @inbook{terando_reich_pacifici_costanza_mckerrow_collazo_2017, title={Uncertainty Quantification and Propagation for Projections of Extremes in Monthly Area Burned Under Climate Change: A Case Study in the Coastal Plain of Georgia, USA}, volume={223}, ISBN={0}, ISSN={2328-8779}, url={http://dx.doi.org/10.1002/9781119028116.ch16}, DOI={10.1002/9781119028116.ch16}, abstractNote={Human-caused climate change is predicted to affect the frequency of hazard-linked extremes. Unusually large wildfires are a type of extreme event that is constrained by climate and can be a hazard to society but also an important ecological disturbance. This chapter focuses on changes in the frequency of extreme monthly area burned by wildfires for the end of the 21st century for a wildfire-prone region in the southeast United States. Predicting changes in area burned is complicated by the large and varied uncertainties in how the climate will change and in the models used to predict those changes. The chapter characterizes and quantifies multiple sources of uncertainty and propagate the expanded prediction intervals of future area burned. It illustrates that while accounting for multiple sources of uncertainty in global change science problems is a difficult task, it will be necessary in order to properly assess the risk of increased exposure to these society-relevant events.}, booktitle={NATURAL HAZARD UNCERTAINTY ASSESSMENT: MODELING AND DECISION SUPPORT}, publisher={John Wiley & Sons, Inc.}, author={Terando, Adam J. and Reich, Brian and Pacifici, Krishna and Costanza, Jennifer and McKerrow, Alexa and Collazo, Jaime A.}, year={2017}, pages={245–256} }
 @article{tavernia_lyons_loges_wilson_collazo_runge_2016, title={An evaluation of rapid methods for monitoring vegetation characteristics of wetland bird habitat}, volume={24}, ISSN={["1572-9834"]}, DOI={10.1007/s11273-015-9476-5}, number={5}, journal={WETLANDS ECOLOGY AND MANAGEMENT}, author={Tavernia, Brian G. and Lyons, James E. and Loges, Brian W. and Wilson, Andrew and Collazo, Jaime A. and Runge, Michael C.}, year={2016}, month={Oct}, pages={495–505} }
 @article{matechou_nicholls_morgan_collazo_lyons_2016, title={Bayesian analysis of Jolly-Seber type models}, volume={23}, ISSN={["1573-3009"]}, DOI={10.1007/s10651-016-0352-0}, abstractNote={We propose the use of finite mixtures of continuous distributions in modelling the process by which new individuals, that arrive in groups, become part of a wildlife population. We demonstrate this approach using a data set of migrating semipalmated sandpipers (Calidris pussila) for which we extend existing stopover models to allow for individuals to have different behaviour in terms of their stopover duration at the site. We demonstrate the use of reversible jump MCMC methods to derive posterior distributions for the model parameters and the models, simultaneously. The algorithm moves between models with different numbers of arrival groups as well as between models with different numbers of behavioural groups. The approach is shown to provide new ecological insights about the stopover behaviour of semipalmated sandpipers but is generally applicable to any population in which animals arrive in groups and potentially exhibit heterogeneity in terms of one or more other processes.}, number={4}, journal={ENVIRONMENTAL AND ECOLOGICAL STATISTICS}, author={Matechou, Eleni and Nicholls, Geoff K. and Morgan, Byron J. T. and Collazo, Jaime A. and Lyons, James E.}, year={2016}, month={Dec}, pages={531–547} }
 @article{costanza_abt_mckerrow_collazo_2016, title={Bioenergy production and forest landscape change in the southeastern United States}, volume={9}, ISSN={1757-1693}, url={http://dx.doi.org/10.1111/gcbb.12386}, DOI={10.1111/gcbb.12386}, abstractNote={Abstract}, number={5}, journal={GCB Bioenergy}, publisher={Wiley}, author={Costanza, Jennifer K. and Abt, Robert C. and McKerrow, Alexa J. and Collazo, Jaime A.}, year={2016}, month={Aug}, pages={924–939} }
 @article{parks_collazo_colon_alvarez_diaz_2016, title={Change in Numbers of Resident and Migratory Shorebirds at the Cabo Rojo Salt Flats, Puerto Rico, USA (1985-2014)}, volume={39}, ISSN={["1938-5390"]}, DOI={10.1675/063.039.0213}, abstractNote={Abstract. 
 North American migratory shorebirds have declined markedly since the 1980s, underscoring the importance of population surveys to conduct status and trend assessments. Shorebird surveys were conducted during three multi-year periods between 1985 and 2014 and used to assess changes in numbers and species composition at the Cabo Rojo Salt Flats, Puerto Rico, USA, a site of regional importance in the eastern Caribbean. Eight fewer species (total = 21) were recorded in 2013–2014 as compared to the 29 from 1985–1992; all eight species were Nearctic migrants. Small calidrids had the highest population counts; however, this suite of species and all others experienced a ≥ 70% decline. Combined counts from the salt flats and neighboring wetlands in 2013–2014 were lower than counts only from the Cabo Rojo Salt Flats in two previous multi-year survey periods, which indicated a real change in numbers not just a shift in wetland use. Invertebrate prey density was lower in 2013–2014 than in 1994. Body fat condition of Semipalmated Sandpipers (Calidris pusilla), an index of habitat quality, did not differ between 1985–1992 and 2013–2014. These findings do not exclude the possibility that other species might be affected by lower prey density, or that local declines in numbers reflect changes at hemispheric, not local, scales. The magnitude of change between local and hemispheric scales closely matched for some species. Continued monitoring at the salt flats is warranted to help gauge the status of shorebirds in Puerto Rico and discern the probable cause of declines. Monitoring other sites in the Caribbean is needed for stronger inferences about regional status and trends.}, number={2}, journal={WATERBIRDS}, author={Parks, Morgan A. and Collazo, Jaime A. and Colon, Jose A. and Alvarez, Katsi R. Ramos and Diaz, Oscar}, year={2016}, month={Jun}, pages={209–214} }
 @article{khalyani_gould_harmsen_terando_quinones_collazo_2016, title={Climate Change Implications for Tropical Islands: Interpolating and Interpreting Statistically Downscaled GCM Projections for Management and Planning*}, volume={55}, ISSN={["1558-8432"]}, DOI={10.1175/jamc-d-15-0182.1}, abstractNote={Abstract}, number={2}, journal={JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY}, author={Khalyani, Azad Henareh and Gould, William A. and Harmsen, Eric and Terando, Adam and Quinones, Maya and Collazo, Jaime A.}, year={2016}, month={Feb}, pages={265–282} }
 @article{parks_collazo_alvarez_2016, title={Factors affecting wetland connectivity for wintering semipalmated sandpipers (Calidris pusilla) in the Caribbean}, volume={39}, DOI={10.1675/063.039.0304}, abstractNote={Abstract. 
 Wetland connectivity provides migratory shorebirds varying options to meet energy requirements to survive and complete their annual cycle. Multiple factors mediate movement and residency of spatially segregated wetlands. Information on these factors is lacking in the tropics, yet such information is invaluable for conservation design. The influence of seven biotic and abiotic factors on local movement and residency rates of Semipalmated Sandpipers (Calidris pusilla) among three major wetlands in southwestern Puerto Rico in 2013–2014 was assessed using multi-state models. The model with highest support (AICc wi= 0.78) indicated that weekly residency rates increased seasonally, and were positively influenced by bird abundance and the interaction of prey density and rainfall. Movement rates were negatively influenced by inter-wetland distance, which varied annually, ranging from 0.01 ± 0.004 to 0.33 ± 0.08. Age class (adult, juvenile), extent of shoreline habitat (km), and body condition (estimated percent fat) did not influence residency rates (95% CIs overlapped Betas). Our findings indicated that coastal wetlands in southwestern Puerto Rico were connected, pointing at the joint value of salt flats and mangroves for overwintering Semipalmated Sandpipers. Connectivity between different types of wetlands likely widens resource diversity, which is essential for coping with unpredictable environments. Additional work is needed to generalize our understanding of inter-wetland dynamics and their potential benefits to inform shorebird conservation strategies in the Caribbean.}, number={3}, journal={Waterbirds}, author={Parks, M. A. and Collazo, Jaime and Alvarez, K. R. R.}, year={2016}, pages={250–259} }
 @article{irizarry_collazo_dinsmore_2016, title={Occupancy dynamics in human-modified landscapes in a tropical island: implications for conservation design}, volume={22}, ISSN={["1472-4642"]}, DOI={10.1111/ddi.12415}, abstractNote={Abstract}, number={4}, journal={DIVERSITY AND DISTRIBUTIONS}, author={Irizarry, Julissa I. and Collazo, Jaime A. and Dinsmore, Stephen J.}, year={2016}, month={Apr}, pages={410–421} }
 @article{tarr_rubino_costanza_mckerrow_collazo_abt_2016, title={Projected gains and losses of wildlife habitat from bioenergy-induced landscape change}, volume={9}, ISSN={1757-1693}, url={http://dx.doi.org/10.1111/gcbb.12383}, DOI={10.1111/gcbb.12383}, abstractNote={Abstract}, number={5}, journal={GCB Bioenergy}, publisher={Wiley}, author={Tarr, Nathan M. and Rubino, Matthew J. and Costanza, Jennifer K. and McKerrow, Alexa J. and Collazo, Jaime A. and Abt, Robert C.}, year={2016}, month={Aug}, pages={909–923} }
 @article{lyons_collazo_herring_2016, title={Testing assumptions for conservation of migratory shorebirds and coastal managed wetlands}, volume={24}, ISSN={["1572-9834"]}, DOI={10.1007/s11273-015-9477-4}, number={5}, journal={WETLANDS ECOLOGY AND MANAGEMENT}, author={Lyons, James E. and Collazo, Jaime A. and Herring, Garth}, year={2016}, month={Oct}, pages={507–520} }
 @article{costanza_abt_mckerrow_collazo_2015, title={Linking state-and-transition simulation and timber supply models for forest biomass production scenarios}, volume={2}, ISSN={2372-0352}, url={http://dx.doi.org/10.3934/environsci.2015.2.180}, DOI={10.3934/environsci.2015.2.180}, abstractNote={We linked state-and-transition simulation models (STSMs) with an economics-based timber supply model to examine landscape dynamics in North Carolina through 2050 for three scenarios of forest biomass production. Forest biomass could be an important source of renewable energy in the future, but there is currently much uncertainty about how biomass production would impact landscapes. In the southeastern US, if forests become important sources of biomass for bioenergy, we expect increased land-use change and forest management. STSMs are ideal for simulating these landscape changes, but the amounts of change will depend on drivers such as timber prices and demand for forest land, which are best captured with forest economic models. We first developed state-and-transition model pathways in the ST-Sim software platform for 49 vegetation and land-use types that incorporated each expected type of landscape change. Next, for the three biomass production scenarios, the SubRegional Timber Supply Model (SRTS) was used to determine the annual areas of thinning and harvest in five broad forest types, as well as annual areas converted among those forest types, agricultural, and urban lands. The SRTS output was used to define area targets for STSMs in ST-Sim under two scenarios of biomass production and one baseline, business-as-usual scenario. We show that ST-Sim output matched SRTS targets in most cases. Landscape dynamics results indicate that, compared with the baseline scenario, forest biomass production leads to more forest and, specifically, more intensively managed forest on the landscape by 2050. Thus, the STSMs, informed by forest economics models, provide important information about potential landscape effects of bioenergy production.}, number={2}, journal={AIMS Environmental Science}, publisher={American Institute of Mathematical Sciences (AIMS)}, author={Costanza, Jennifer K. and Abt, Robert C. and McKerrow, Alexa J. and Collazo, Jaime A.}, year={2015}, pages={180–202} }
 @article{costanza_terando_mckerrow_collazo_2015, title={Modeling climate change, urbanization, and fire effects on Pinus palustris ecosystems of the southeastern U.S.}, volume={151}, ISSN={0301-4797}, url={http://dx.doi.org/10.1016/j.jenvman.2014.12.032}, DOI={10.1016/j.jenvman.2014.12.032}, abstractNote={Managing ecosystems for resilience and sustainability requires understanding how they will respond to future anthropogenic drivers such as climate change and urbanization. In fire-dependent ecosystems, predicting this response requires a focus on how these drivers will impact fire regimes. Here, we use scenarios of climate change, urbanization and management to simulate the future dynamics of the critically endangered and fire-dependent longleaf pine (Pinus palustris) ecosystem. We investigated how climate change and urbanization will affect the ecosystem, and whether the two conservation goals of a 135% increase in total longleaf area and a doubling of fire-maintained open-canopy habitat can be achieved in the face of these drivers. Our results show that while climatic warming had little effect on the wildfire regime, and thus on longleaf pine dynamics, urban growth led to an 8% reduction in annual wildfire area. The management scenarios we tested increase the ecosystem's total extent by up to 62% and result in expansion of open-canopy longleaf by as much as 216%, meeting one of the two conservation goals for the ecosystem. We find that both conservation goals for this ecosystem, which is climate-resilient but vulnerable to urbanization, are only attainable if a greater focus is placed on restoration of non-longleaf areas as opposed to maintaining existing longleaf stands. Our approach demonstrates the importance of accounting for multiple relevant anthropogenic threats in an ecosystem-specific context in order to facilitate more effective management actions.}, journal={Journal of Environmental Management}, publisher={Elsevier BV}, author={Costanza, Jennifer K. and Terando, Adam J. and McKerrow, Alexa J. and Collazo, Jaime A.}, year={2015}, month={Mar}, pages={186–199} }
 @article{pacifici_zipkin_collazo_irizarry_dewan_2014, title={Guidelines for a priori grouping of species in hierarchical community models}, volume={4}, ISSN={["2045-7758"]}, DOI={10.1002/ece3.976}, abstractNote={Abstract}, number={7}, journal={ECOLOGY AND EVOLUTION}, author={Pacifici, Krishna and Zipkin, Elise F. and Collazo, Jaime A. and Irizarry, Julissa I. and DeWan, Amielle}, year={2014}, month={Apr}, pages={877–888} }
 @article{hines_nichols_collazo_2014, title={Multiseason occupancy models for correlated replicate surveys}, volume={5}, ISSN={["2041-2096"]}, DOI={10.1111/2041-210x.12186}, abstractNote={Summary}, number={6}, journal={METHODS IN ECOLOGY AND EVOLUTION}, author={Hines, James E. and Nichols, James D. and Collazo, Jaime A.}, year={2014}, month={Jun}, pages={583–591} }
 @article{van beusekom_hay_viger_gould_collazo_khalyani_2014, title={THE EFFECTS OF CHANGING LAND COVER ON STREAMFLOW SIMULATION IN PUERTO RICO}, volume={50}, ISSN={["1752-1688"]}, DOI={10.1111/jawr.12227}, abstractNote={Abstract}, number={6}, journal={JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION}, author={Van Beusekom, Ashley E. and Hay, Lauren E. and Viger, Roland J. and Gould, William A. and Collazo, Jaime A. and Khalyani, Azad Henareh}, year={2014}, month={Dec}, pages={1575–1593} }
 @article{terando_costanza_belyea_dunn_mckerrow_collazo_2014, title={The Southern Megalopolis: Using the Past to Predict the Future of Urban Sprawl in the Southeast U.S}, volume={9}, ISSN={1932-6203}, url={http://dx.doi.org/10.1371/journal.pone.0102261}, DOI={10.1371/journal.pone.0102261}, abstractNote={The future health of ecosystems is arguably as dependent on urban sprawl as it is on human-caused climatic warming. Urban sprawl strongly impacts the urban ecosystems it creates and the natural and agro-ecosystems that it displaces and fragments. Here, we project urban sprawl changes for the next 50 years for the fast-growing Southeast U.S. Previous studies have focused on modeling population density, but the urban extent is arguably as important as population density per se in terms of its ecological and conservation impacts. We develop simulations using the SLEUTH urban growth model that complement population-driven models but focus on spatial pattern and extent. To better capture the reach of low-density suburban development, we extend the capabilities of SLEUTH by incorporating street-network information. Our simulations point to a future in which the extent of urbanization in the Southeast is projected to increase by 101% to 192%. Our results highlight areas where ecosystem fragmentation is likely, and serve as a benchmark to explore the challenging tradeoffs between ecosystem health, economic growth and cultural desires.}, number={7}, journal={PLoS ONE}, publisher={Public Library of Science (PLoS)}, author={Terando, Adam J. and Costanza, Jennifer and Belyea, Curtis and Dunn, Robert R. and McKerrow, Alexa and Collazo, Jaime A.}, editor={Layman, Craig A.Editor}, year={2014}, month={Jul}, pages={e102261} }
 @article{kirste_hoffmann_sachet_bobea_bryan_bryan_nenstiel_hoffmann_maria_collazo_et al._2013, title={Ge doped GaN with controllable high carrier concentration for plasmonic applications}, volume={103}, ISSN={0003-6951 1077-3118}, url={http://dx.doi.org/10.1063/1.4848555}, DOI={10.1063/1.4848555}, abstractNote={Controllable Ge doping in GaN is demonstrated for carrier concentrations of up to 2.4 × 1020 cm−3. Low temperature luminescence spectra from the highly doped samples reveal band gap renormalization and band filling (Burstein-Moss shift) in addition to a sharp transition. Infrared ellipsometry spectra demonstrate the existence of electron plasma with an energy around 3500 cm−1 and a surface plasma with an energy around 2000 cm−1. These findings open possibilities for the application of highly doped GaN for plasmonic devices.}, number={24}, journal={Applied Physics Letters}, publisher={AIP Publishing}, author={Kirste, Ronny and Hoffmann, Marc P. and Sachet, Edward and Bobea, Milena and Bryan, Zachary and Bryan, Isaac and Nenstiel, Christian and Hoffmann, Axel and Maria, Jon-Paul and Collazo, Ramón and et al.}, year={2013}, month={Dec}, pages={242107} }
 @article{matechou_morgan_pledger_collazo_lyons_2013, title={Integrated Analysis of Capture-Recapture-Resighting Data and Counts of Unmarked Birds at Stop-Over Sites}, volume={18}, ISSN={["1537-2693"]}, DOI={10.1007/s13253-013-0127-0}, number={1}, journal={JOURNAL OF AGRICULTURAL BIOLOGICAL AND ENVIRONMENTAL STATISTICS}, author={Matechou, E. and Morgan, B. J. T. and Pledger, S. and Collazo, J. A. and Lyons, J. E.}, year={2013}, month={Mar}, pages={120–135} }
 @article{rogers_collazo_drew_2013, title={King Rail (Rallus elegans) Occupancy and Abundance in Fire Managed Coastal Marshes in North Carolina and Virginia}, volume={36}, ISSN={["1938-5390"]}, DOI={10.1675/063.036.0207}, abstractNote={Abstract. 
 Curbing the declining trends of King Rails (Rallus elegans) that occupy freshwater emergent marshes requires an understanding of their ecology and response to management practices. King Rails were surveyed during the breeding season (March-June) at Back Bay and Mackay Island National Wildlife Refuges, Virginia and North Carolina, in 2009 and 2010. Twenty-two plots were surveyed in 2009 and 41 in 2010. Annual occupancy estimates were based on pooled data encompassing both refuges. In 2010, occupancy and abundance of King Rails were also estimated for each refuge and assessed with respect to fire management. Plots in 2010 were classified as recently burned (0–1 years-since-burn [YSB]) or ≥ 2 YSB. Occupancy probability was similar between 2009 (0.68 ± 0.14) and 2010 (0.62 ± 0.08). In 2010, occupancy probability was higher at Mackay Island (0.95 ± 0.06) than Back Bay (0.69 ± 0.13). Mean plot abundance (Mackay Island = 1.47 ± 0.38; Back Bay = 0.66 ± 0.22) was also higher. The probability of occupying 0–1 YSB plots was higher at both refuges (Mackay Island = 0.95 ± 0.06; Back Bay = 0.72 ± 0.20) when compared to ≥ 2 YSB plots (Mackay Island = 0.69 ± 0.13; Back Bay = 0.25 ± 0.12). Location strongly influenced occupancy of King Rails. It is plausible that the marsh composition (natural vs. created) accounted for the observed differences in occupancy. Natural marshes may provide higher quality habitat (e.g., resource availability) for King Rails than created marshes.}, number={2}, journal={WATERBIRDS}, author={Rogers, Samantha L. and Collazo, Jaime A. and Drew, C. Ashton}, year={2013}, month={Jun}, pages={179–188} }
 @article{obernuefemann_collazo_lyons_2013, title={Local Movements and Wetland Connectivity at a Migratory Stopover of Semipalmated Sandpipers (Calidris pusilla) in the Southeastern United States}, volume={36}, ISSN={["1938-5390"]}, DOI={10.1675/063.036.0110}, abstractNote={Abstract. 
 Semipalmated Sandpipers (Calidris pusilla) use coastal wetlands in the southeastern United States during spring migration, some engaging in short-distance movements and brief refueling stops. Knowledge about the scale and factors that influence these movements could guide conservation planning, but often this information is not available. The influence of inter-wetland distance, prey biomass, amount of foraging habitat at depths of 0–4 cm, and density of migrating Semipalmated Sandpipers on their movement and stopover residency was investigated at the Tom Yawkey Wildlife Center in South Carolina in spring 2007. Tom Yawkey Wildlife Center contains three clusters of coastal wetlands separated by 2.6, 2.8 and 4.1 km. Probability of moving among wetland clusters and stopover residency were estimated using multi-state mark-recapture models and encounter histories from 502 marked Semipalmated Sandpipers. Sixty-four percent of Semipalmated Sandpipers remained within 2 km of site-of-capture for the duration of the study. Movement probabilities were negatively influenced by inter-cluster distance and Semipalmated Sandpiper density. Probability of moving between clusters 2.6–2.8 km apart was higher than clusters separated by 4.1 km. Semipalmated Sandpipers were more likely to depart the study area and resume migration after feeding in wetland clusters with abundant prey and accessible habitat. The interaction between prey and accessible habitat led to instances where Semipalmated Sandpipers were more likely to remain in wetlands with low prey levels, but high accessible habitat, or low accessible habitat, but high prey levels. Local movements among alternative foraging locations were facilitated when wetlands were < 2.8 km apart, highlighting the benefits of integrated management at small scales.}, number={1}, journal={WATERBIRDS}, author={Obernuefemann, Kelsey P. and Collazo, Jaime A. and Lyons, James E.}, year={2013}, month={Mar}, pages={63–76} }
 @article{wiewel_dinsmore_collazo_2013, title={NEST SURVIVAL AND BREEDING BIOLOGY OF THE PUERTO RICAN BULLFINCH (LOXIGILLA PORTORICENSIS) IN SOUTHWESTERN PUERTO RICO}, volume={125}, ISSN={["1938-5447"]}, DOI={10.1676/12-175.1}, abstractNote={Abstract Breeding biology information, including nest survival estimates, are lacking for many nesting species in Puerto Rico. We studied the endemic Puerto Rican Bullfinch (Loxigilla portoricensis), and modeled daily nest survival to better understand the effects of several factors on daily nest survival. In 2009 and 2010 we monitored 37 bullfinch nests at two sites in southwestern Puerto Rico. Predation was the most important cause of nest failure. Ten nest survival models received approximately equal support. No temporal trends in nest survival were supported over others. Results suggested that available fruit is important for successful nesting, increased precipitation is related to higher nest survival, nest survival varied by site, and increased nest height is related to lower nest survival in bullfinches. Under the top model, daily nest survival rates for each site and nest stage ranged from 0.83–0.86% in 2009 and 0.80–0.93% in 2010. This information on nest survival and factors that influence it increases our understanding of the breeding biology of the bullfinch, and will ultimately help inform future studies and conservation efforts in southwestern Puerto Rico.}, number={4}, journal={WILSON JOURNAL OF ORNITHOLOGY}, author={Wiewel, Amber N. M. and Dinsmore, Stephen J. and Collazo, Jaime A.}, year={2013}, month={Dec}, pages={720–730} }
 @article{rogers_collazo_drew_2013, title={Nest occurrence and survival of King Rails in fire-managed coastal marshes in North Carolina and Virginia}, volume={84}, ISSN={["1557-9263"]}, DOI={10.1111/jofo.12035}, abstractNote={Prescribed burning maintains marsh habitat, but its impact on breeding King Rails (Rallus elegans) is poorly understood. This practice may serve as a means to enhance populations of a species whose numbers are declining in the southeastern United States. We used call-broadcast surveys and nest searches to categorize the state of occupied plots by the presence or non-presence of nesting activity in the Back Bay region, North Carolina and Virginia, in 2010. We also used nest video surveillance to estimate nest survival in 2009 and 2010. The probabilities that a surveyed plot was occupied (1) and contained an active nest (2) were higher in recently burned marsh plots (0–1 year-since-burn [YSB]) than in plots with ≥2 YSB at Mackay Island and Back Bay National Wildlife Refuges (NWRs). Highest probabilities were recorded in 0–1 YSB plots at Mackay Island NWR ( = 0.96 ± 0.04, = 0.75 ± 0.18), and the lowest in ≥2 YSB plots at Back Bay NWR ( = 0.21 ± 0.10, = 0.03 ± 0.04). Nest survival from egg laying to hatching (31 d) was 0.48 (95% confidence interval [CI] = 0.06–0.83), with an estimated 0.79 (95% CI = 0.29–0.96) survival rate for the incubation stage (21 d). These nest survival estimates for King Rails in fire-managed marshes were similar to estimates for other populations. Measures of vegetation cover, proxies for concealment, did not differ between nest sites and unused sites, even within recently burned marshes. This lack of differences in vegetation structure suggests that regrowth occurs rapidly during the period between burning (winter months) and the onset of reproduction (late April). Thus, recently burned marshes may benefit nesting King Rails by providing nest concealment. In addition, burned marshes may enhance availability of many invertebrates. Although we found that the probability that surveyed plots contained active nests was higher in recently burned marsh plots, estimates of fledging success are needed before marsh burns can be considered an effective means of fostering population growth. 
 
RESUMEN 
 
Ocurrencia de nidos y supervivencia del Rascon real en pantanos costeros con manejo de fuego en Carolina del Norte y Virginia 
 
 
 
Los incendios controlados ayudan a mantener los pantanos, pero su impacto en la reproduccion del Rascon real (Rallus elegans) esta poco estudiado. Esta practica puede servir como un medio de incrementar poblaciones de una especie cuyos numeros han declinado en el sudeste de Estados Unidos. Usamos censos con playback y busqueda de nidos a fin de categorizar el estado de ocupacion de parcelas por la presencia o ausencia de actividad de nido en la region de Back Bay, en Carolina del Norte y Virginia, en 2010. Utilizamos tambien monitoreo por video de nidos para estimar la supervivencia de nido en 2009 y 2010. Las probabilidades de que una parcela censada se encontrara ocupado () y de que contuviese nidos activos () fueron mas altos en pantanos recientemente incendiados (0–1 anos desde quema [ADQ]) que en parcelas con ≥2 ADQ en Isla Mackay y en el Refugio Nacional de Vida Silvestre (RNVS) de Back Bay. Las probabilidades mas altas fueron registradas en parcelas con 0–1 ADQ en Isla Mackay Island RNVS ( = 0.96 ± 0.04, = 0.75 ± 0.18), y la mas baja en parcelas con ADQ ⩾2 en Back Bay RNVS ( = 0.21 ± 0.10, = 0.03 ± 0.04). La supervivencia de nido desde la puesto de huevos hasta la eclosion (31 dias) fue de 0.48 (95% IC = 0.06–0.83), con un estimado de 0.79 (95% IC = 0.29–0.96) para la tasa de supervivencia para el estadio de incubacion (21 dias). Estos estimados para la supervivencia de nidos para el Rascon real en pantanos con manejo del fuego controlados fueron similares a los estimados para otras poblaciones. Las medidas de cubertura vegetal, representantes de camuflaje, no difirieron entre las parcelas con nidos y las parcelas sin nidos, aun dentro de pantanos recientemente quemados. Esta falta de diferencias en la estructura de la vegetacion sugiere que el crecimiento de la vegetacion ocurre rapidamente en el periodo entre la quema (meses de invierno) y el inicio de la temporada reproductiva (fines de Abril). Asi, pantanos recientemente quemados podrian beneficiar a la nidada del Rascon real al proveer camuflaje para el nido. Adicionalmente, los pantanos quemados podrian aumentar la disponibilidad de muchos invertebrados. Aun cuando encontramos que la probabilidad de que las parcelas censadas contuviesen nidos activos era mayor en parcelas recientemente quemadas, estimaciones del exito de los volantones son necesarias antes de que la quema en pantanos pueda ser considerada como un medio efectivo de estimular el crecimiento poblacional.}, number={4}, journal={JOURNAL OF FIELD ORNITHOLOGY}, author={Rogers, Samantha L. and Collazo, Jaime A. and Drew, Christina A.}, year={2013}, month={Dec}, pages={355–366} }
 @article{collazo_fackler_pacifici_white_llerandi-roman_dinsmore_2013, title={Sophia title}, volume={77}, number={6}, journal={Journal of Wildlife Management}, author={Collazo, J. A. and Fackler, P. L. and Pacifici, K. and White, T. H. and Llerandi-Roman, I. and Dinsmore, S. J.}, year={2013}, pages={1124–1134} }
 @article{schwarzer_collazo_niles_brush_douglass_percival_2012, title={ANNUAL SURVIVAL OF RED KNOTS (CALIDRIS CANUTUS RUFA) WINTERING IN FLORIDA}, volume={129}, ISSN={["1938-4254"]}, DOI={10.1525/auk.2012.11269}, abstractNote={ABSTRACT. 
 Populations of Red Knots (Calidris canutus rufa) have declined an estimated 80% in the past 25 years. Declines are primarily attributed to dwindling food resources in Delaware Bay, their last migratory stopover before the breeding grounds. Red Knots wintering in Florida also decreased in numbers, prompting the need to estimate local vital rates to determine whether local factors contribute to declining trends. We estimated age-specific annual survival rates and compared them with estimates from populations of Red Knots wintering in South America using the Barker model. Adult annual survival rates between 2005 and 2010 averaged 0.89 ± 0.02 [SD]; range: 0.86–0.94) and were similar to estimates reported for Delaware Bay (0.87–0.92). Juvenile survival (0.95 ± 0.06 [SE]) and adult fidelity (0.81 ± 0.05 [SE]) were also high. However, juvenile survival did not include the period between fledging and arrival in Florida, a period of potentially high mortality. Similar adult survival rates suggested that there was no apparent survival cost for adults migrating to and from Florida compared with those migrating elsewhere. Factors that influence adult survival likely affect populations of C. c. rufa where they co-occur (e.g., breeding grounds, staging areas). Low year-to-year variation (CV = 2.24%) of adult survival suggests that other vital rates with higher variation (e.g., recruitment) may exert a stronger influence on population growth and partly account for the observed decline. Status projections require estimates of fecundity, year-round juvenile survival, and winter distribution in the United States.}, number={4}, journal={AUK}, author={Schwarzer, Amy C. and Collazo, Jaime A. and Niles, Lawrence J. and Brush, Janell M. and Douglass, Nancy J. and Percival, H. Franklin}, year={2012}, month={Oct}, pages={725–733} }
 @article{stolen_collazo_percival_2012, title={GROUP-FORAGING EFFECTS ON CAPTURE RATE IN WADING BIRDS}, volume={114}, ISSN={["1938-5129"]}, DOI={10.1525/cond.2012.110159}, abstractNote={Abstract. 
 Group foraging is common among wading birds, and the reasons why individuals forage in groups are of theoretical and practical interest. Although aggregations of foraging wading birds usually form within patches of high-quality habitat, individual wading birds can sometimes increase success by foraging near others. We investigated the hypothesis that individuals derive a benefit from foraging in groups separate from benefits due to habitat quality. We measured the capture rates of birds foraging solitarily and in groups at foraging sites and paired unused sites and used generalized linear mixed models and information-theoretic model selection to access the evidence that individuals increase their foraging success when foraging in groups. The capture rate of Great Egrets (Ardea alba) in groups was higher, supporting the hypothesis that individuals benefit from the presence of other foragers. This rate was highest in intermediate-sized groups but tapered off in larger groups, suggesting that interference competition limits success. Tricolored Herons (Egretta tricolor) showed a similar but less statistically precise pattern. Contrary to expectation, the capture rate of Snowy Egrets (E. thula) foraging alone was higher than that of those in groups. Although fish abundance was greater at used than at unused sites, and at sites with groups than at sites with individuals, we did not detect an effect of prey density on capture rate, probably because prey density was fairly high at all sites studied. Our study adds to the evidence for a direct benefit to individuals due to the presence of other foragers in aggregations.}, number={4}, journal={CONDOR}, author={Stolen, Eric D. and Collazo, Jaime A. and Percival, H. Franklin}, year={2012}, month={Nov}, pages={744–754} }
 @article{veran_kleiner_choquet_collazo_nichols_2012, title={Modeling habitat dynamics accounting for possible misclassification}, volume={27}, ISSN={["1572-9761"]}, DOI={10.1007/s10980-012-9746-z}, number={7}, journal={LANDSCAPE ECOLOGY}, author={Veran, Sophie and Kleiner, Kevin J. and Choquet, Remi and Collazo, Jaime A. and Nichols, James D.}, year={2012}, month={Aug}, pages={943–956} }
 @article{borkhataria_collazo_groom_jordan-garcia_2012, title={Shade-grown coffee in Puerto Rico: Opportunities to preserve biodiversity while reinvigorating a struggling agricultural commodity}, volume={149}, ISSN={["1873-2305"]}, DOI={10.1016/j.agee.2010.12.023}, abstractNote={Shade-grown coffee contributes to biodiversity conservation and has many ecological benefits. We reviewed historical trends in coffee production and interviewed 100 coffee growers in 1999 to determine current management practices and attitudes toward the cultivation of sun and shade coffee in Puerto Rico. We discuss the outlook for the coffee industry in the 21st century and implications for biodiversity conservation, hoping lessons from Puerto Rico will apply to the international coffee industry. Throughout the 20th century, government intervention, including subsidies and technical assistance, supported coffee farming in Puerto Rico. In an effort to modernize coffee production and increase yields, the conversion from shade to sun coffee plantations was encouraged. Despite government support, the amount of land devoted to this once dominant agricultural commodity declined markedly between 1982 and 2007 (84%), due to labor shortages, low income, and catastrophic hurricanes. We found that a return to shaded plantations would be embraced by most farmers. Growers of shaded coffee were generally happier with their cultivation practices (89.3% satisfied) than growers of sun coffee (60.9% satisfied), valued biodiversity, and were willing to cultivate coffee under shade if given similar incentives to those received for farming sun coffee. The future of the coffee industry in Puerto Rico may depend on government programs that capitalize upon emerging markets for sustainably produced, shade-grown coffee. We conclude that where governments have close ties to the coffee industry, they should strive to wed economic development with the conservation of biodiversity and associated ecological services by providing support and incentives for the production of shade coffee.}, journal={AGRICULTURE ECOSYSTEMS & ENVIRONMENT}, author={Borkhataria, Rena and Collazo, Jaime A. and Groom, Martha J. and Jordan-Garcia, Adrian}, year={2012}, month={Mar}, pages={164–170} }
 @article{costanza_hulcr_koch_earnhardt_mckerrow_dunn_collazo_2012, title={Simulating the effects of the southern pine beetle on regional dynamics 60 years into the future}, volume={244}, ISSN={0304-3800}, url={http://dx.doi.org/10.1016/j.ecolmodel.2012.06.037}, DOI={10.1016/j.ecolmodel.2012.06.037}, abstractNote={We developed a spatially explicit model that simulated future southern pine beetle (Dendroctonus frontalis, SPB) dynamics and pine forest management for a real landscape over 60 years to inform regional forest management. The SPB has a considerable effect on forest dynamics in the Southeastern United States, especially in loblolly pine (Pinus taeda) stands that are managed for timber production. Regional outbreaks of SPB occur in bursts resulting in elimination of entire stands and major economic loss. These outbreaks are often interspersed with decades of inactivity, making long-term modeling of SPB dynamics challenging. Forest management techniques, including thinning, have proven effective and are often recommended as a way to prevent SPB attack, yet the robustness of current management practices to long-term SPB dynamics has not been examined. We used data from previously documented SPB infestations and forest inventory data to model four scenarios of SPB dynamics and pine forest management. We incorporated two levels of beetle pressure: a background low level, and a higher level in which SPB had the potential to spread among pine stands. For each level of beetle pressure, we modeled two scenarios of forest management: one assuming forests would be managed continuously via thinning, and one with a reduction in thinning. For our study area in Georgia, Florida, and Alabama, we found that beetle pressure and forest management both influenced the landscape effects of SPB. Under increased SPB pressure, even with continuous management, the area of pine forests affected across the region was six times greater than under baseline SPB levels. However, under high SPB pressure, continuous management decreased the area affected by nearly half compared with reduced management. By incorporating a range of forest and SPB dynamics over long time scales, our results extend previous modeling studies, and inform forest managers and policy-makers about the potential future effects of SPB. Our model can also be used to investigate the effects of additional scenarios on SPB dynamics, such as alternative management or climate change.}, journal={Ecological Modelling}, publisher={Elsevier BV}, author={Costanza, Jennifer K. and Hulcr, Jiri and Koch, Frank H. and Earnhardt, Todd and McKerrow, Alexa J. and Dunn, Rob R. and Collazo, Jaime A.}, year={2012}, month={Oct}, pages={93–103} }
 @article{borkhataria_collazo_groom_2012, title={Species abundance and potential biological control services in shade vs. sun coffee in Puerto Rico}, volume={151}, ISSN={["0167-8809"]}, DOI={10.1016/j.agee.2012.01.025}, abstractNote={Birds, lizards and insects were surveyed in three sun and three shade coffee plantations in Puerto Rico to provide a comprehensive comparison of biodiversity between plantations types and to identify potential interrelationships (e.g., biological or natural control services) between members of each taxon and coffee pests. Abundance of avian species, including insectivorous species, was significantly higher in shade coffee. Anolis cristatellus and A. stratulus were significantly more abundant in sun plantations whereas A. gundlachi and A. evermanni were detected more frequently in shade plantations. Insects in the orders Coleoptera, Diptera, Hemiptera, Hymenoptera, Lepidoptera, Neuroptera, and Psocoptera were significantly more abundant in shade coffee, while orthopterans were more abundant in sun. The coffee leaf miner (Leucoptera coffeela) and the flatid planthopper (Petrusa epilepsis) did not differ significantly between plantation types, nor did the abundance of the wasp complex that parasitizes the coffee leaf miner. These findings confirmed that shade plantations harbor a wide array of elements of biodiversity; but sun plantations may also harbor many elements of biodiversity, and in some cases, in higher abundance than in shade plantations.}, journal={AGRICULTURE ECOSYSTEMS & ENVIRONMENT}, author={Borkhataria, Rena R. and Collazo, Jaime A. and Groom, Martha J.}, year={2012}, month={Apr}, pages={1–5} }
 @article{borkhataria_frederick_keller_collazo_2012, title={TEMPORAL VARIATION IN LOCAL WETLAND HYDROLOGY INFLUENCES POSTDISPERSAL SURVIVAL OF JUVENILE WOOD STORKS (MYCTERIA AMERICANA)}, volume={129}, ISSN={["1938-4254"]}, DOI={10.1525/auk.2012.11244}, abstractNote={ABSTRACT. 
 Since the 1960s, anthropogenic shifts in the timing and distribution of surface-water flows in the Everglades have pushed back the onset of reproduction in Wood Storks (Mycteria americana). Late nesting increases the probability that juveniles leave the colony during the summer rainy season, when water levels are high and prey animals unavailable. We used satellite telemetry to track firstyear survival of 85 Wood Storks from southern Florida over 4 years. We further evaluated survival in relation to hydrologic and physiologic variables, including water depths, surface-water recession rates, May rainfall, use of wetland habitats, sex, total feather mercury, whiteblood-cell counts, and heterophih:lymphocyte ratios for a subset of 71 birds, using a known-fates model in Program MARK. Juveniles that dispersed from the colony during favorable conditions (surface water depths <25 cm) had a first-year survival rate of 0.37 ± 0.06 (SE), compared with 0.15 ± 0.04 for those that dispersed into unfavorable conditions (depths >25 cm). General hydrologie conditions (favorable vs. unfavorable), wetland habitat use, and white-blood-cell counts were the best predictors of monthly survival, and the strongest effects were associated with the first month postdispersal. Our study is the first to show a relationship between temporally fluctuating hydrologic variables and survival of juvenile Wood Storks, highlighting the need to consider the timing of hydrologic manipulations when managing wetlands for birds. We conclude that human-induced changes in the temporal patterns of hydrology may have important consequences for the phenology and, ultimately, the demography of wetland birds.}, number={3}, journal={AUK}, author={Borkhataria, Rena R. and Frederick, Peter C. and Keller, Rebecca A. and Collazo, Jaime A.}, year={2012}, month={Jul}, pages={517–528} }
 @article{iglecia_collazo_mckerrow_2012, title={Use of Occupancy Models to Evaluate Expert Knowledge-based Species-Habitat Relationships}, volume={7}, ISSN={["1712-6568"]}, DOI={10.5751/ace-00551-070205}, abstractNote={Expert knowledge-based species-habitat relationships are used extensively to guide conservation planning, particularly when data are scarce. Purported relationships describe the initial state of knowledge, but are rarely tested. We assessed support in the data for suitability rankings of vegetation types based on expert knowledge for three terrestrial avian species in the South Atlantic Coastal Plain of the United States. Experts used published studies, natural history, survey data, and field experience to rank vegetation types as optimal, suitable, and marginal. We used single-season occupancy models, coupled with land cover and Breeding Bird Survey data, to examine the hypothesis that patterns of occupancy conformed to species-habitat suitability rankings purported by experts. Purported habitat suitability was validated for two of three species. As predicted for the Eastern Wood-Pewee (Contopus virens) and Brown-headed Nuthatch (Sitta pusilla), occupancy was strongly influenced by vegetation types classified as “optimal habitat” by the species suitability rankings for nuthatches and wood-pewees. Contrary to predictions, Red-headed Woodpecker (Melanerpes erythrocephalus) models that included vegetation types as covariates received similar support by the data as models without vegetation types. For all three species, occupancy was also related to sampling latitude. Our results suggest that covariates representing other habitat requirements might be necessary to model occurrence of generalist species like the woodpecker. The modeling approach described herein provides a means to test expert knowledge-based species-habitat relationships, and hence, help guide conservation planning. RESUME. Les relations especes-habitat etablies a partir des connaissances d’experts sont largement utilisees pour orienter la planification de la conservation, surtout lorsque les donnees sont rares. Ces relations presumees representent les rudiments de la connaissance, mais sont rarement testees. L’adequation du classement de milieux etabli par des experts a ete evaluee pour trois especes de passereaux de la Plaine cotiere de l’Atlantique Sud, aux Etats-Unis. Les experts ont utilise des donnees publiees (recherches, histoire naturelle, releves) et leur experience sur le terrain afin de classer les milieux selon trois categories, soit optimaux, adequats ou marginaux. Nous avons applique des modeles de presence, fondes sur une seule saison, a des donnees d’occupation du sol et de releves d’oiseaux nicheurs afin d’examiner l’hypothese voulant que les profils de presence concordent avec le classement de la qualite des milieux presume par les experts. La qualite presumee des milieux a ete validee pour deux des trois especes. Comme predit pour le Pioui de l’Est (Contopus virens) et la Sittelle a tete brune (Sitta pusilla), la presence de l’espece s’est revelee fortement liee aux milieux classes comme « optimaux » pour les sittelles et les piouis. Contrairement aux predictions pour le Pic a tete rouge (Melanerpes erythrocephalus), les modeles qui incluaient les milieux comme covariables etaient equivalents aux modeles qui ne les incluaient pas. Chez les trois especes, la presence etait aussi correlee a la latitude de l’echantillonnage. Nos resultats semblent indiquer qu’il serait peut-etre necessaire d’inclure des covariables relatives a d’autres besoins en matiere d’habitat afin de modeliser la presence d’especes generalistes comme le pic. L’approche de modelisation decrite dans cette etude permet de tester les relations especes-habitat etablies d’apres les connaissances d’experts et, par consequent, contribue a orienter la planification de la conservation.}, number={2}, journal={AVIAN CONSERVATION AND ECOLOGY}, author={Iglecia, Monica N. and Collazo, Jaime A. and McKerrow, Alexa J.}, year={2012}, month={Dec} }
 @article{collazo_gilliam_miranda-castro_2010, title={Functional Response Models to Estimate Feeding Rates of Wading Birds}, volume={33}, ISSN={["1524-4695"]}, DOI={10.1675/063.033.0104}, abstractNote={Abstract. 
 Forager (predator) abundance may mediate feeding rates in wading birds. Yet, when modeled, feeding rates are typically derived from the purely prey-dependent Holling Type II (HoII) functional response model. Estimates of feeding rates are necessary to evaluate wading bird foraging strategies and their role in food webs; thus, models that incorporate predator dependence warrant consideration. Here, data collected in a mangrove swamp in Puerto Rico in 1994 were reanalyzed, reporting feeding rates for mixed-species flocks after comparing fits of the HoII model, as used in the original work, to the Beddington-DeAngelis (BD) and Crowley-Martin (CM) predator-dependent models. Model CM received most support (AIC c wi = 0.44), but models BD and HoII were plausible alternatives (&Dgr;AIC c ≤ 2). Results suggested that feeding rates were constrained by predator abundance. Reductions in rates were attributed to interference, which was consistent with the independently observed increase in aggression as flock size increased (P < 0.05). Substantial discrepancies between the CM and HoII models were possible depending on flock sizes used to model feeding rates. However, inferences derived from the HoII model, as used in the original work, were sound. While Holling's Type II and other purely prey-dependent models have fostered advances in wading bird foraging ecology, evaluating models that incorporate predator dependence could lead to a more adequate description of data and processes of interest. The mechanistic bases used to derive models used here lead to biologically interpretable results and advance understanding of wading bird foraging ecology.}, number={1}, journal={WATERBIRDS}, author={Collazo, Jaime A. and Gilliam, James F. and Miranda-Castro, Leopoldo}, year={2010}, month={Mar}, pages={33–40} }
 @article{lombard_collazo_mcnair_2010, title={NEST AND CHICK SURVIVAL AND COLONY-SITE DYNAMICS OF LEAST TERNS IN THE US VIRGIN ISLANDS}, volume={112}, ISSN={["0010-5422"]}, DOI={10.1525/cond.2010.090042}, abstractNote={Abstract. We report nest and chick survival and colony-site dynamics of the Least Tern (Sternula antillarum). These results are the first for the Caribbean and were derived with likelihood-based approaches from 4640 nests and 44 chicks fitted with transmitters monitored in 52 colonies at St. Croix, U.S. Virgin Islands, 2003–2006. Managed colonies excluded, overall daily nest survival (±SE) was 0.92 ± 0.03 (period survival = 0.18). Daily nest survival of managed colonies (fenced) was significantly higher (0.97 ± 0.02; period survival = 0.51). Variation in nest survival was best explained by a negative linear trend in daily survival, influenced by year, rain, large colony size, and nesting habitat. Daily nest-survival rates at sandy beaches (0.94 ± 0.02), offshore cays (0.93 ± 0.005), and saltflats (0.91 ± 0.02) did not differ significantly. The period survival of chicks was 0.30 ± 0.11. Estimated fledglings per nest attempt were 0.06. Demographic assessments suggested that higher reproductive rates are required for maintenance (&lgr; ≥ 1). Managed colonies could meet nest-survival thresholds, but complementary measures are needed to increase chick survival. Our findings suggest that management should target sites harboring large colonies because they had higher nest success and higher probability of use in subsequent seasons. The colonies' site dynamics suggested that immigration from other populations is plausible. This possibility relaxes breeding-productivity thresholds and advocates for coordinated conservation among populations on neighboring islands. Estimates of age-specific survival and connectivity are needed for the status of the species to be assessed appropriately and conservation priorities set.}, number={1}, journal={CONDOR}, author={Lombard, Claudia D. and Collazo, Jaime A. and McNair, Douglas B.}, year={2010}, month={Feb}, pages={56–64} }
 @article{rice_collazo_tweedie_dalmau_mita_xie_sitar_2010, title={Surface preparation and homoepitaxial deposition of AlN on (0001)-oriented AlN substrates by metalorganic chemical vapor deposition}, volume={108}, ISSN={0021-8979 1089-7550}, url={http://dx.doi.org/10.1063/1.3467522}, DOI={10.1063/1.3467522}, abstractNote={Chemical surface treatments were conducted on mechanically polished (MP) and chemomechanically polished (CMP) (0001)-oriented single crystalline aluminum nitride (AlN) substrates to determine a surface preparation procedure for the homoepitaxial deposition of AlN epitaxial layers by metalorganic chemical vapor deposition. MP AlN substrates characterized by atomic force microscopy exhibited 0.5 nm rms roughness and polishing scratches, while CMP AlN substrates exhibited 0.1 nm rms roughness and were scratch-free. X-ray photoelectron spectroscopy analysis of MP and CMP AlN substrates indicated the presence of a surface hydroxide layer composed of mixed aluminum oxide hydroxide and aluminum trihydroxide. Wet etching with sulfuric and phosphoric acid mixtures reduced the amount of surface hydroxide. Ammonia annealing at 1250 °C converted the substrate hydroxide layer to AlN and increased the rms roughness of MP and CMP AlN substrates to 2.2 nm and 0.2 nm, respectively. AlN epitaxial layers were deposited at 1100–1250 °C under 20 Torr total pressure with a V/III ratio of 180–300 in either N2 or H2 diluent. High-resolution x-ray diffraction measurements revealed that AlN epitaxial layers deposited on MP substrates were strained due to nucleation and coalescence of AlN grains on the mechanically damaged surfaces. AlN deposited on CMP substrates was epitaxial and strain-free. Thermodynamic models for nitridation and AlN deposition were also proposed and evaluated.}, number={4}, journal={Journal of Applied Physics}, publisher={AIP Publishing}, author={Rice, A. and Collazo, R. and Tweedie, J. and Dalmau, R. and Mita, S. and Xie, J. and Sitar, Z.}, year={2010}, month={Aug}, pages={043510} }
 @article{howard_papich_felt_long_mckeon_bond_torreilles_luong_green_2010, title={The pharmacokinetics of enrofloxacin in adult African clawed frogs (Xenopus laevis)}, volume={49}, number={6}, journal={Journal of the American Association for Laboratory Animal Science}, author={Howard, A. M. and Papich, M. G. and Felt, S. A. and Long, C. T. and McKeon, G. P. and Bond, E. S. and Torreilles, S. L. and Luong, R. H. and Green, S. L.}, year={2010}, pages={800–804} }
 @article{annetta_mangrum_holmes_collazo_cheng_2009, title={Bridging Realty to Virtual Reality: Investigating gender effect and student engagement on learning through video game play in an elementary school classroom}, volume={31}, ISSN={["1464-5289"]}, DOI={10.1080/09500690801968656}, abstractNote={The purpose of this study was to examine students' learning of simple machines, a fifth‐grade (ages 10–11) forces and motion unit, and student engagement using a teacher‐created Multiplayer Educational Gaming Application. This mixed‐method study collected pre‐test/post‐test results to determine student knowledge about simple machines. A survey ascertained the time spent using the computer for general purposes, and the time spent playing computer games as a function of gender. The pre‐test and post‐test design involved 74 students, 31 males and 43 females, who played the Dr. Friction Multiplayer Educational Gaming Application for several days in the middle of the unit. Results showed the females averaged using the computer more than their male counterparts and males played video games more than females. Analysis of covariance suggested no significant difference between the factor gender (p > .05) but statistically significant differences in gain scores (p = .001). Observations and qualitative focus groups suggested high student engagement and how video game technology can scaffold learning of simple machines.}, number={8}, journal={INTERNATIONAL JOURNAL OF SCIENCE EDUCATION}, author={Annetta, Leonard and Mangrum, Jennifer and Holmes, Shawn and Collazo, Kimberly and Cheng, Meng-Tzu}, year={2009}, pages={1091–1113} }
 @article{herring_collazo_2009, title={Site Characteristics and Prey Abundance at Foraging Sites Used by Lesser Scaup (Aythya affinis) Wintering in Florida}, volume={8}, ISSN={["1528-7092"]}, DOI={10.1656/058.008.0215}, abstractNote={Abstract 
 We examined site characteristics and prey abundances where wintering Aythya affinis (Lesser Scaup; hereafter scaup) foraged within three regions of the Indian River Lagoon system in central Florida. We observed that scaup concentrated in the Indian and Banana rivers; however, density of prey items did not differ between foraging sites and random sites. We also found that site characteristics were similar between foraging and random sites. Differences in site characteristics between random points across all three regions did not explain the distribution of foraging scaup (no scaup foraged in the Mosquito Lagoon); however, prey densities were approximately 3 times lower in the Mosquito Lagoon region. Our study suggests that current habitat conditions within the northern Indian River Lagoon system meet the overwintering requirements of scaup; however, prey densities in the Mosquito Lagoon may have been too low to be profitable for foraging scaup during the period of our study.}, number={2}, journal={SOUTHEASTERN NATURALIST}, author={Herring, Garth and Collazo, Jaime A.}, year={2009}, pages={363–374} }
 @article{stolen_collazo_percival_2009, title={Vegetation Effects on Fish Distribution in Impounded Salt Marshes}, volume={8}, ISSN={["1938-5412"]}, DOI={10.1656/058.008.0311}, abstractNote={Abstract We compared the density and biomass of resident fish in vegetated and unvegetated flooded habitats of impounded salt marshes in the northern Indian River Lagoon (IRL) Estuary of east-central Florida. A 1-m2 throw trap was used to sample fish in randomly located, paired sample plots (n = 198 pairs) over 5 seasons in 7 impoundments. We collected a total of 15 fish taxa, and 88% of the fishes we identified from the samples belonged to three species: Cyprinodon variegatus (Sheepshead Minnow), Gambusia holbrooki (Eastern Mosquitofish), and Poecilia latipinna (Sailfin Molly). Vegetated habitat usually had higher density and biomass of fish. Mean fish density (and 95% confidence interval) for vegetated and unvegetated sites were 8.2 (6.7–9.9) and 2.0 (1.6–2.4) individuals m-2, respectively; mean biomass (and 95%) confidence interval) for vegetated and unvegetated sites were 3.0 (2.5–3.7) and 1.1 (0.9–1.4) g m-2, respectively. We confirmed previous findings that impounded salt marshes of the northern IRL Estuary produce a high standing stock of resident fishes. Seasonal patterns of abundance were consistent with fish moving between vegetated and unvegetated habitat as water levels changed in the estuary. Differences in density, mean size, and species composition of resident fishes between vegetated and unvegetated habitats have important implications for movement of biomass and nutrients out of salt marsh by piscivores (e.g., wading birds and fishes) via a trophic relay.}, number={3}, journal={SOUTHEASTERN NATURALIST}, author={Stolen, Eric D. and Collazo, Jaime A. and Percival, H. Franklin}, year={2009}, pages={503–514} }
 @article{liu_collazo_mita_sitar_pennycook_duscher_2008, title={Direct Observation of Inversion Domain Boundaries of GaN onc-Sapphire at Sub-ångstrom Resolution}, volume={20}, ISSN={0935-9648 1521-4095}, url={http://dx.doi.org/10.1002/adma.200702522}, DOI={10.1002/adma.200702522}, abstractNote={Wide-bandgap III–nitrides have seen enormous success in modern electronic, optoelectronic, and even spintronic devices. Recently, interest has grown in manipulating the crystal polarity of GaN having a wurtzite structure, which provides a new degree of freedom for investigating III–nitrides and their novel devices. These studies include work on the inversion domain boundaries (IDBs) of GaN, which separate adjacent domains of different polarity. Ten years ago, Northrup et al. performed first-principles calculations of domain-boundary energies and proposed the structure shown in Figure 1, based on its very low energy (25 meV A ). Since then, no direct, indisputable test has been carried out to determine the exact boundary structure. At the same time, many unique properties have been observed at the IDBs. Among these is the remarkable effect, observed by Stutzmann et al. that the IDB can act as a rectifying junction when biased by two electrodes placed on adjacent Gaand N-face regions. The boundary between two adjacent domains with different polarity has been shown to be a very efficient radiative recombination center, which may have potential application for novel light-emitting devices. Meanwhile, it was found that the rectifying behavior of the IDBs can be explained by ab initio density functional calculations, assuming the IDBs have a structure as shown in Figure 1 (where a thin AlN layer is used to invert the polarity of GaN). However, the IDB structure has never been determined directly and their real structure remains unconfirmed. Here we show that we have determined directly the IDB structure, including the determination of GaN polarity, by aberration-corrected scanning transmission electron microscopy (STEM) at sub-Angstrom}, number={11}, journal={Advanced Materials}, publisher={Wiley}, author={Liu, Fude and Collazo, Ramon and Mita, Seiji and Sitar, Zlatko and Pennycook, Stephen J. and Duscher, Gerd}, year={2008}, month={Jun}, pages={2162–2165} }
 @article{lyons_collazo_guglielmo_2008, title={Plasma metabolites and migration physiology of semipalmated sandpipers: refueling performance at five latitudes}, volume={155}, ISSN={["1432-1939"]}, DOI={10.1007/s00442-007-0921-x}, abstractNote={Long-distance bird migration is fueled by energy gathered at stopover sites along the migration route. The refueling rate at stopover sites is a determinant of time spent at stopovers and impacts the overall speed of migration. Refueling rate during spring migration may influence the fitness of individuals via changes in the probability of successful migration and reproduction during the subsequent breeding season. We evaluated four plasma lipid metabolites (triglycerides, phospholipids, beta-OH-butyrate, and glycerol) as measures of refueling rate in free-living semipalmated sandpipers (Calidris pusilla) captured at non-breeding areas. We described the spatial and temporal variation in metabolite concentrations among one winter site in the Dominican Republic and four stopover sites in the South Atlantic and Mid-Atlantic Coastal Plain regions of North America. Triglycerides and beta-OH-butyrate clearly identified spatial variation in refueling rate and stopover habitat quality. Metabolite profiles indicated that birds had higher refueling rates at one site in the Mid-Atlantic Coastal Plain than at three sites on the South Atlantic Coastal Plain and one site in the Dominican Republic. Temporal variation in lipid metabolites during the migration season suggested that male semipalmated sandpipers gained more weight at stopovers on the South Atlantic Coastal Plain than did females, evidence of differential migration strategies for the sexes. Plasma lipid metabolites provide information on migration physiology that may help determine stopover habitat quality and reveal how migratory populations use stopover sites to refuel and successfully complete long-distance migrations.}, number={3}, journal={OECOLOGIA}, author={Lyons, James E. and Collazo, Jaime A. and Guglielmo, Christopher G.}, year={2008}, month={Mar}, pages={417–427} }
 @article{aukema_carlo_collazo_2007, title={Landscape assessment of tree communities in the northern karst region of Puerto Rico}, volume={189}, ISSN={["1573-5052"]}, DOI={10.1007/s11258-006-9169-5}, abstractNote={The northern karst of Puerto Rico is a unique formation that contains one of the island's largest remaining forested tracts. The region is under ever-increasing human pressure, but large portions of it are being considered for conservation. Forest classification of the region is at a coarse scale, such that it is considered one vegetation type. We asked whether there were distinct tree assemblages which would necessitate targeted conservation strategies to ensure their protection. We examined tree species and communities across the region at three different major topographic positions along mogotes, or haystack-shaped hills. We found distinct tree communities on hilltops and valleys, with significantly more non-native species in valleys and significantly more endemic species on hilltops and hillsides. At a landscape level, we identified at least four different communities within each topographic position. Two mogote top communities were separated geographically (west and south) within the region, while two others co-occurred in the east-central part of the region. Mogote side and valley communities were less distinct geographically. Temperature, elevation, and precipitation were important variables in separating some communities, suggesting that abiotic stress may play an important role in the distribution of some species. In contrast, the lack of geographic separations of other communities suggested that variables such as soil conditions, land use and biotic interactions such as dispersal limitation may also be important. Conservation planning strategies should target the south, west, and east-central areas that harbor distinct mogote top plant communities to ensure protection of the widest range of tree species and communities in the karst region.}, number={1}, journal={PLANT ECOLOGY}, author={Aukema, Juliann E. and Carlo, Tomas A. and Collazo, Jaime A.}, year={2007}, month={Mar}, pages={101–115} }
 @article{rice_collazo_alldredge_harrington_lewis_2007, title={Local annual survival and seasonal residency rates of semipalmated sandpipers (Calidris pusilla) in Puerto Rico}, volume={124}, ISSN={["0004-8038"]}, DOI={10.1642/0004-8038(2007)124[1397:LASASR]2.0.CO;2}, abstractNote={Abstract We report seasonal residency and local annual survival rates of migratory Semipalmated Sandpipers (Calidris pusilla) at the Cabo Rojo salt flats, Puerto Rico. Residency rate (daily probability of remaining on the flats) was 0.991 ± 0.001 (x̄ ± SE), yielding a mean length of stay of 110 days. This finding supports the inclusion of the Caribbean as part of the species' winter range. Average estimated percentage of fat was low but increased throughout the season, which suggests that birds replenish some spent fat reserves and strive for energetic maintenance. Local annual survival rate was 0.62 ± 0.04, within the range of values reported for breeding populations at Manitoba and Alaska (0.53–0.76). The similarity was not unexpected because estimates were obtained annually but at opposite sites of their annual migratory movements. Birds captured at the salt flats appeared to be a mix of birds from various parts of the breeding range, judging from morphology (culmen's coefficient of variation = 9.1, n = 106). This suggested that origin (breeding area) of birds and their proportion in the data should be ascertained and accounted for in analyses to glean the full conservation implications of winter-based annual survival estimates. Those data are needed to unravel the possibility that individuals of distinct populations are affected by differential mortality factors across different migratory routes. Mean length of stay strongly suggested that habitat quality at the salt flats was high. Rainfall and tidal flow combine to increase food availability during fall. The salt flats dry up gradually toward late January, at the onset of the dry season. Semipalmated Sandpipers may move west to other Greater Antilles or south to sites such as coastal Surinam until the onset of spring migration. They are not an oversummering species at the salt flats. Conservation efforts in the Caribbean region require understanding the dynamics of this species throughout winter to protect essential habitat. Tasas de Supervivencia Anual Local y de Residencia Estacional de Calidris pusilla en Puerto Rico}, number={4}, journal={AUK}, author={Rice, Susan M. and Collazo, Jaime A. and Alldredge, Mathew W. and Harrington, Brian A. and Lewis, Allen R.}, year={2007}, month={Oct}, pages={1397–1406} }
 @article{podolsky_simons_collazo_2007, title={Modeling population growth of the ovenbird (Seiurus aurocapilla) in the southern appalachians}, volume={124}, ISSN={["0004-8038"]}, DOI={10.1642/0004-8038(2007)124[1359:MPGOTO]2.0.CO;2}, abstractNote={Abstract Studies of source-sink dynamics are often prompted by concerns about negative population trends. Estimates of population trajectories are usually based on assumptions about survival rates and empirical measures of fecundity. Most models ignore the influence of the rates of renesting and multiple brooding. We used the Ovenbird (Seiurus aurocapilla) as a model Neotropical migratory songbird species to investigate the relative effects of annual female survival and components of annual fecundity on population growth rates. We applied productivity data from a three- year field study and data from Hann (1937) to several models of annual fecundity to examine the sensitivity of lambda to variations in annual female survival and the likelihood of renesting and double-brooding. Our simulations illustrate the importance of incorporating estimates of annual survival and rates of additional breeding attempts in songbird population models because population growth rates are quite sensitive to variations in these parameters. Lambda is especially sensitive to survival estimates and changes with them at the same order of magnitude. Whenever feasible, female survival and probabilities of additional breeding attempts should be estimated by direct methods. The indirect methods used in our study (annual female survival estimated from the age ratio of breeding females, and rates of renesting and double- brooding determined from the timing of reproduction) probably underestimated these parameters. Modelado del Crecimiento Poblacional de Seiurus aurocapilla en el Sur de los Apalaches}, number={4}, journal={AUK}, author={Podolsky, Andrei L. and Simons, Theodore R. and Collazo, Jaime A.}, year={2007}, month={Oct}, pages={1359–1372} }
 @article{stolen_collazo_percival_2007, title={Scale-dependent habitat selection of nesting Great Egrets and Snowy Egrets}, volume={30}, ISSN={["1938-5390"]}, DOI={10.1675/1524-4695(2007)030[0384:SHSONG]2.0.CO;2}, abstractNote={Abstract Foraging habitat selection of nesting Great Egrets (Ardea alba) and Snowy Egrets (Egretta thula) was investigated within an estuary with extensive impounded salt marsh habitat. Using a geographic information system, available habitat was partitioned into concentric bands at five, ten, and 15 km radius from nesting colonies to assess the relative effects of habitat composition and distance on habitat selection. Snowy Egrets were more likely than Great Egrets to depart colonies and travel to foraging sites in groups, but both species usually arrived at sites that were occupied by other wading birds. Mean flight distances were 6.2 km (SE = 0.4, N = 28, range 1.8-10.7 km) for Great Egrets and 4.7 km (SE = 0.48, N = 31, range 0.7-12.5 km) for Snowy Egrets. At the broadest spatial scale both species used impounded (mostly salt marsh) and estuarine edge habitat more than expected based on availability while avoiding unimpounded (mostly fresh water wetland) habitat. At more local scales habitat use matched availability. Interpretation of habitat preference differed with the types of habitat that were included and the maximum distance that habitat was considered available. These results illustrate that caution is needed when interpreting the results of habitat preference studies when individuals are constrained in their choice of habitats, such as for central place foragers.}, number={3}, journal={WATERBIRDS}, author={Stolen, Eric D. and Collazo, Jaime A. and Percival, H. Franklin}, year={2007}, month={Sep}, pages={384–393} }
 @article{alldredge_pollock_simons_collazo_shriner_2007, title={Time-of-detection method for estimating abundance from point-count surveys}, volume={124}, ISSN={["1938-4254"]}, DOI={10.1642/0004-8038(2007)124[653:TMFEAF]2.0.CO;2}, abstractNote={Abstract Point-count surveys are often used to collect data on the abundance and distribution of birds, generally as an index of relative abundance. Valid comparison of these indices assumes that the detection process is comparable over space and time. These restrictive assumptions can be eliminated by estimating detection probabilities directly. We generalize a recently proposed removal model for estimating detection probabilities using a time-of-detection approach, which can account for more sources of variation in point-count data. This method is specifically designed to account for variation in detection probabilities associated with singing rates of birds. Our model accounts for both availability bias and detection bias by modeling the combined probability that a bird sings during the count, and the probability that it is detected given that it sings. The model requires dividing the count into several intervals and recording detections of individual birds in each interval. We develop maximum-likelihood estimators for this approach and provide a full suite of models based on capture-recapture models, including covariate models. We present two examples of this method: one for four species of songbirds surveyed in Great Smoky Mountains National Park using three unequal intervals, and one for the Pearly-eyed Thrasher (Margarops fuscatus) surveyed in Puerto Rico using four equal intervals. Models incorporating individual heterogeneity were selected for all data sets using information-theoretic model-selection techniques. Detection probabilities varied among count-time intervals, which suggests that birds may be responding to observers. We recommend applying this method to surveys with four or more equal intervals to reduce assumptions and to take full advantage of standard capture-recapture software. The time-of-detection approach provides a better understanding of the detection process, especially when singing rates of individual birds affect detection probabilities. Estimación de la Abundancia en Puntos de Conteo Mediante el Método del Tiempo de Detección}, number={2}, journal={AUK}, author={Alldredge, Mathew W. and Pollock, Kenneth H. and Simons, Theodore R. and Collazo, Jaime A. and Shriner, Susan A.}, year={2007}, month={Apr}, pages={653–664} }
 @article{borkhataria_collazo_groom_2006, title={Additive effects of vertebrate predators on insects in a Puerto Rican coffee plantation}, volume={16}, ISSN={["1939-5582"]}, DOI={10.1890/1051-0761(2006)016[0696:AEOVPO]2.0.CO;2}, abstractNote={A variety of studies have established the value of shaded coffee plantations as habitat for birds. While the value of birds as biological controls in coffee has received some attention, the interactions between birds and other predators of insects have not been tested. We used exclosures to examine the effects of vertebrate predators on the arthropods associated with coffee, in particular the coffee leafminer (Leucoptera coffeella) and the flatid planthopper Petrusa epilepsis, in a shaded coffee plantation in Puerto Rico. We used a 2 x 2 factorial design with four treatments: exclusion of birds, lizards, birds and lizards, and control (no exclusion). Abundance of insects > 5 mm increased when birds or both birds and lizards were removed. Birds and lizards had an additive effect for insects < 5 mm and for all insects combined. Coffee leafminers showed a weak response to removal of predators while planthopper abundance increased significantly in the absence of avian predators. Arthropod predators and parasitoids did not differ significantly between treatments. Our findings suggest that vertebrate insectivores have an additive effect on insects in coffee and may help control abundances of some coffee pests. Equally important, we present evidence suggesting that they do not interfere with other known natural enemies of coffee pests.}, number={2}, journal={ECOLOGICAL APPLICATIONS}, author={Borkhataria, RR and Collazo, JA and Groom, MJ}, year={2006}, month={Apr}, pages={696–703} }
 @article{allen_krieger_walters_collazo_2006, title={Associations of breeding birds with fire-influenced and riparian-upland gradients in a longleaf pine ecosystem}, volume={123}, ISSN={["1938-4254"]}, DOI={10.1642/0004-8038(2006)123[1110:AOBBWF]2.0.CO;2}, abstractNote={Abstract We determined the effects of fire history and a riparian-upland gradient on the breeding bird community at Fort Bragg Military Installation in North Carolina, one of the largest remnant areas of the endangered longleaf pine (Pinus palustris) ecosystem. Study sites were classified into two treatments: fire-intense (areas experiencing growing-season burns) and fire-suppressed (areas lacking fires). Within each treatment, bird and vegetation data were recorded at point-count stations positioned at three distances from streamhead pocosins to characterize the riparian-upland habitat gradient: 0, 75, and ≥150 m. Total bird abundance and species richness varied significantly along the riparian-upland gradient, with pocosins contributing greatly to avian biodiversity. Our data revealed strong effects of fire history and riparian-upland gradient on bird species, which we described in terms of breeding-bird assemblages. Members of the open longleaf assemblage (e.g., Red- cockaded Woodpecker [Picoides borealis], Bachman's Sparrow [Aimophila aestivalis]) were most common in fire-intense areas and at upland locations. Members of the fire-suppressed assemblage (e.g., Wood Thrush [Hylocichla mustelina], Ovenbird [Seiurus aurocapilla]) were confined to pocosins in fire-intense areas, but became more abundant in fire-suppressed areas. Members of the pocosin assemblage (e.g., Eastern Towhee [Pipilo erythropthalamus], Common Yellowthroat [Geothlypis trichas]) were largely confined to pocosins and, in some cases, were most abundant in fire-intense pocosins. Fire suppression increased structural diversity of vegetation and promoted one breeding-bird assemblage (fire-suppressed), but at the expense of two others (open longleaf, pocosin). Continued management of Fort Bragg to promote longleaf pine restoration is essential for supporting conservation of the open-longleaf bird assemblage; in addition, it will benefit the pocosin assemblage. Asociaciones de Aves Reproductivas con Áreas Influenciadas por el Fuego y con Gradientes Ribereños-Tierras Altas en un Ecosistema de Pinus palustris}, number={4}, journal={AUK}, author={Allen, Jennifer C. and Krieger, Sharlene M. and Walters, Jeffrey R. and Collazo, Jaime A.}, year={2006}, month={Oct}, pages={1110–1128} }
 @article{gleffe_collazo_groom_miranda-castro_2006, title={Avian reproduction and the conservation value of shaded coffee plantations}, volume={17}, number={2}, journal={Ornitologia Neotropical}, author={Gleffe, J. D. and Collazo, J. A. and Groom, M. J. and Miranda-Castro, L.}, year={2006}, pages={271–282} }
 @article{herring_collazo_2006, title={Lesser scaup winter foraging and nutrient reserve acquisition in east-central Florida}, volume={70}, ISSN={["1937-2817"]}, DOI={10.2193/0022-541X(2006)70[1682:LSWFAN]2.0.CO;2}, abstractNote={Abstract Lesser scaup (Aythya affinis) populations have been declining since the late 1970s. One of the explanations to account for this decline, the spring-condition hypothesis (SCH), is based on the premise that scaup are limited by their ability to acquire or maintain nutrient reserves during migration to the breeding grounds, leading to an impairment of their reproductive potential. Available evidence suggests that endogenous reserves required for reproduction are obtained at a later stage of migration or after arrival at the breeding grounds, not wintering sites. However, only one study has addressed body-condition levels on a southern wintering site in the last decade, with results limited to the wintering grounds on the Mississippi Flyway. We documented foraging behavior, nutrient levels, and body mass of lesser scaup in east-central Florida, USA, where 62% of the Atlantic Flyway population overwinters, during the winters of 2002 and 2003. Diurnal foraging did not increase seasonally. Nocturnal foraging increased seasonally by 76% or 43 minutes per night in females and by 478% or 1.9 hours per night in males. Measures of body condition did not change seasonally during 2002 for either sex. Between early and later winter in 2003 corrected body mass (CBM) and lipid reserves of male scaup increased 77 g and 39 g, respectively. Our results suggest that lesser scaup maintain or may slightly improve their physiological condition in east-central Florida during winter. Lower body mass and differences in nutrient levels in east-central Florida, compared to a wintering site in Louisiana, likely stem from geographic variation and lower thermal requirements associated with the warmer Florida environment. Lesser scaup depart Florida with sufficient reserves to initiate spring migration, but they maximize nutrient reserves used during reproduction elsewhere during migration or on the breeding grounds. These results suggest that maintaining the ecological integrity of this wintering ground is critical in minimizing winter mortality and preventing it from becoming an ancillary factor in current declines. Future research should address understanding survival rates during spring migration and at critical staging areas to provide new insight into the ramifications of scaup leaving wintering habitats such as MINWR with lower body condition than at other wintering sites in other flyways.}, number={6}, journal={JOURNAL OF WILDLIFE MANAGEMENT}, author={Herring, Garth and Collazo, Jaime A.}, year={2006}, month={Dec}, pages={1682–1689} }
 @article{saracco_collazo_groom_carlo_2005, title={Crop size and fruit neighborhood effects on bird visitation to fruiting Schefflera morototoni trees in Puerto Rico}, volume={37}, ISSN={["1744-7429"]}, DOI={10.1111/j.1744-7429.2005.04040.x}, abstractNote={ABSTRACT}, number={1}, journal={BIOTROPICA}, author={Saracco, JF and Collazo, JA and Groom, MJ and Carlo, TA}, year={2005}, month={Mar}, pages={81–87} }
 @article{white_collazo_vilella_guerrer_2005, title={Effects of Hurricane Georges on habitat use by captive-reared Hispaniolan Parrots (Amazona ventralis) released in the Dominican Republic}, volume={16}, number={3}, journal={Ornitologia Neotropical}, author={White, T. H. and Collazo, J. A. and Vilella, F. J. and Guerrer, S. A.}, year={2005}, pages={405–417} }
 @article{rivera-milan_collazo_stahala_moore_davis_herring_steinkamp_pagliaro_thompson_bracey_2005, title={Estimation of density and population size and recommendations for monitoring trends of Bahama parrots on Great Abaco and Great Inagua}, volume={33}, ISSN={["1938-5463"]}, DOI={10.2193/0091-7648(2005)33[823:EODAPS]2.0.CO;2}, abstractNote={Abstract Once abundant and widely distributed, the Bahama parrot (Amazona leucocephala bahamensis) currently inhabits only the Great Abaco and Great Inagua Islands of the Bahamas. In January 2003 and May 2002–2004, we conducted point-transect surveys (a type of distance sampling) to estimate density and population size and make recommendations for monitoring trends. Density ranged from 0.061 (SE = 0.013) to 0.085 (SE = 0.018) parrots/ha and population size ranged from 1,600 (SE = 354) to 2,386 (SE = 508) parrots when extrapolated to the 26,154 ha and 28,162 ha covered by surveys on Abaco in May 2002 and 2003, respectively. Density was 0.183 (SE = 0.049) and 0.153 (SE = 0.042) parrots/ha and population size was 5,344 (SE = 1,431) and 4,450 (SE = 1,435) parrots when extrapolated to the 29,174 ha covered by surveys on Inagua in May 2003 and 2004, respectively. Because parrot distribution was clumped, we would need to survey 213–882 points on Abaco and 258–1,659 points on Inagua to obtain a CV of 10–20% for estimated density. Cluster size and its variability and clumping increased in wintertime, making surveys imprecise and cost-ineffective. Surveys were reasonably precise and cost-effective in springtime, and we recommend conducting them when parrots are pairing and selecting nesting sites. Survey data should be collected yearly as part of an integrated monitoring strategy to estimate density and other key demographic parameters and improve our understanding of the ecological dynamics of these geographically isolated parrot populations at risk of extinction.}, number={3}, journal={WILDLIFE SOCIETY BULLETIN}, author={Rivera-Milan, FF and Collazo, JA and Stahala, C and Moore, WJ and Davis, A and Herring, G and Steinkamp, M and Pagliaro, R and Thompson, JL and Bracey, W}, year={2005}, pages={823–834} }
 @article{herring_collazo_2005, title={Habitat use, movements and home range of wintering Lesser Scaup in Florida}, volume={28}, ISSN={["1938-5390"]}, DOI={10.1675/1524-4695(2005)028[0071:HUMAHR]2.0.CO;2}, abstractNote={Abstract Radio telemetry and diurnal time activity budgets were used to show that wintering Lesser Scaup (Aythya affinis) used different habitats for comfort and feeding activities at Merritt Island National Wildlife Refuge (Merritt Island), Florida and adjacent estuarine areas. Management should take this spatial consideration into account. The same data were used to determine if habitat use differed between sexes. Data on movements and home range were used to evaluate habitat quality and potential effects of human disturbance. Scaup foraged more in impounded wetlands and rested more in open estuarine regions. Mean distance between diurnal and nocturnal sites was 2.7 km (SE ± 0.3), and was similar between sexes and from mid to late winter. Male and female fixed kernel home ranges and core use areas did not differ. Mean fixed kernel 95% home range and 50% core use areas were 15.1 km2 (SE ± 2.0) and 2.7 km2 (SE ± 0.5) respectively, representing 3% and 0.5% of surveyed habitats. Males and females used habitats similarly and short distances traveled between diurnal and nocturnal sites suggested that habitat conditions were similar across the impounded wetlands and shallow portions of both the Indian River and Banana River. Sedentary or short movements suggested that disturbance was probably negligible at the principal areas used by Lesser Scaup. Habitat management strategies for scaup should not be restricted to Merritt Island. Adjustments should be made to take into account that maintenance activities occur in adjacent estuarine areas as well.}, number={1}, journal={WATERBIRDS}, author={Herring, G and Collazo, JA}, year={2005}, month={Mar}, pages={71–78} }
 @article{white_collazo_vilella_2005, title={Survival of captive-reared Puerto Rican parrots released in the Caribbean National Forest}, volume={107}, ISSN={["1938-5129"]}, DOI={10.1650/7672}, abstractNote={Abstract We report first-year survival for 34 captive-reared Puerto Rican Parrots (Amazona vittata) released in the Caribbean National Forest, Puerto Rico between 2000 and 2002. The purpose of the releases were to increase population size and the potential number of breeding individuals of the sole extant wild population, and to refine release protocols for eventual reintroduction of a second wild population elsewhere on the island. After extensive prerelease training, we released 10 parrots in 2000, 16 parrots in 2001, and eight parrots in 2002 ranging in age from 1–4 years old. All birds were equipped with radio-transmitters to monitor survival. The overall first-year survival estimate for the 34 parrots was 41% (CI = 22%–61%). Only one parrot died within the first week postrelease, with most (94%) surviving for at least eight weeks after release. Most (54%) documented mortalities were due to raptor predation, which claimed 21% of all released parrots. A captive-reared bird (male, age one), released in 2001, paired with a wild female and fledged two young in 2004. We also calculated survival based on 0% and 50% of observed predation losses and found hypothetical survival rates of 72% and 54%, respectively. Rigorous prerelease training and acclimation was believed to have improved initial postrelease parrot survival, and releasing mixed age-class groups suggests the potential for shortening the time to recruitment. Supervivencia de Individuos de Amazona vittata Criados en Cautiverio y Liberados en el Bosque Nacional del Caribe Resumen. Determinamos la supervivencia de 34 individuos de cotorras Amazona vittata criados en cautiverio y liberados en el Bosque Nacional del Caribe, Puerto Rico entre el 2000 y el 2002. El propósito de las liberaciones era aumentar el tamaño de la población y el número potencial de individuos reproductores en la única población silvestre remanente, y refinar los protocolos de liberación para eventualmente establecer una segunda población silvestre en la isla. Después de un adiestramiento extensivo, liberamos 10 cotorras en el 2000, 16 cotorras en el 2001, y ocho cotorras en el 2002 fluctuando en edades entre uno y cuatro años. Cada individuo se liberó con un radio transmisor para determinar su supervivencia. La tasa general de supervivencia para 34 cotorras después de un año fue de 41% (IC = 22–61%). Sólo una cotorra murió durante la primera semana post-liberación, con la mayoría (94%) sobreviviendo por lo menos ocho semanas después de liberadas. La mayoría (54%) de la mortandad se debió a la depredación por aves rapaces, la que reclamó 21% de todas las cotorras liberadas. Una cotorra criada en cautiverio (macho, un año de edad), y liberada en el 2001, se apareó con una hembra silvestre y produjeron dos volantones en el 2004. Reduciendo la mortandad por aves rapaces informada en este estudio en un 100%, o en un 50%, resultó en tasas hipotéticas de supervivencia del 72% y 54%, respectivamente. Creemos que el adiestramiento y la aclimatación rigurosa pre-liberación mejoraron la supervivencia inicial post-liberación, y que la liberación de grupos de cotorras de edades mixtas sugiere el potencial de acortar el tiempo de reclutamiento.}, number={2}, journal={CONDOR}, author={White, TH and Collazo, JA and Vilella, FJ}, year={2005}, month={May}, pages={424–432} }
 @article{podolsky_simons_collazo_2004, title={A method of food supplementation for ground-foraging insectivorous songbirds}, volume={75}, ISSN={["1557-9263"]}, DOI={10.1648/0273-8570-75.3.296}, abstractNote={Abstract Food supplementation can be an important experimental technique in studies of avian reproductive ecology, energetics, and parental care. We developed a method of food supplementation suitable for ground-foraging insectivorous passerines and tested it on Ovenbird (Seiurus aurocapilla) and Wood Thrushes (Hylocichla mustelina). We provided mealworms at feeding stations made of plastic transparency film covered with a thin layer of green moss. Feeding stations were placed on the ground or on logs or boulders in the vicinity of nests. Direct and indirect evidence suggested that 92% of breeding Ovenbirds and 79% of breeding Wood Thrushes used supplemental food. The impact of non-target consumers was not significant: they were observed eating mealworms at approximately one-third of our food-supplemented nests. However, diurnal non-target consumers were only detected on a single occasion for each species, and nocturnal consumers fed on small amounts of mealworms left after daytime feeding experiments. This method proved very effective for Ovenbirds and Wood Thrushes, and it may be applicable to other ground-foraging insectivorous passerines.}, number={3}, journal={JOURNAL OF FIELD ORNITHOLOGY}, author={Podolsky, AL and Simons, TR and Collazo, JA}, year={2004}, pages={296–302} }
 @article{saracco_collazo_groom_2004, title={How do frugivores track resources? Insights from spatial analyses of bird foraging in a tropical forest}, volume={139}, ISSN={["1432-1939"]}, DOI={10.1007/s00442-004-1493-7}, abstractNote={Frugivores often track ripe fruit abundance closely across local areas despite the ephemeral and typically patchy distributions of this resource. We use spatial auto- and cross-correlation analyses to quantify spatial patterns of fruit abundance and avian frugivory across a 4-month period within a forested 4.05-ha study grid in Puerto Rico. Analyses focused on two tanager species, Spindalis portoricensis and Nesospingus speculiferus, and their principal food plants. Three broad questions are addressed: (1). at what spatial scales is fruit abundance and frugivory patchy; (2). at what spatial scales do frugivores respond to fruit abundance; and (3). to what extent do spatial patterns of frugivory overlap between bird species? Fruit patch size, species composition, and heterogeneity was variable among months, despite fruit patch locations remaining relatively consistent between months. Positive correlations between frugivory and fruit abundance suggested tanagers successfully tracked fruit abundance. Frugivory was, however, more localized than fruit abundance. Scales of spatial overlap in frugivory and monthly variation in the foraging locations of the two tanager species suggested that interspecific facilitation may have been important in determining bird foraging locations. In particular, S. portoricensis, a specialist frugivore, may have relied on the loud calls of the gregarious generalist, N. speculiferus, to find new foraging areas. Such a mechanism could help explain the formation of mixed species feeding flocks and highlights the potential importance of facilitation between species that share resources.}, number={2}, journal={OECOLOGIA}, author={Saracco, JF and Collazo, JA and Groom, MJ}, year={2004}, month={Apr}, pages={235–245} }
 @article{carlo_collazo_groom_2004, title={Influences of fruit diversity and abundance on bird use of two shaded coffee plantations}, volume={36}, ISSN={["0006-3606"]}, DOI={10.1646/1604}, abstractNote={We studied avian foraging at two shaded coffee plantations in Ciales, Puerto Rico. Both coffee plantations contained patches of second-growth forest but differed in shade types; one was a rustic plantation with a species-diverse shade including many fruiting plant species and the other was a commercial polyculture shaded almost solely by Inga vera. We quantified foraging activity of five fruit-eating bird species (Euphonia musica, Loxigilla portoricensis, Nesospingus speculiferus, Spindalis portoricensis, and Vireo altiloquous) and monthly fruit abundance in the coffee plantation and adjacent second-growth forest habitats at each site. Fruits comprised more than 50 percent of the diets for four of five focal bird species. We found a significant difference in the number of foraging records for focal bird species between coffee and forest habitats in the commercial polyculture but found few differences between these habitats in the rustic coffee farm. Overall, foraging activity was positively correlated with the abundance of fruits across study sites. Bird foraging was concentrated on plant species in the genera Cecropia, Miconia, Schefflera, Phoradendron, and Guarea, which together accounted for over 50 percent of frugivory records. Plant species in such genera fruited over prolonged time periods and provided birds with a fairly constant fruit supply. Our findings underscore the importance of fruiting plant species in making coffee plantations suitable habitat for birds and suggest that native fruiting plants be incorporated in coffee farms for avian conservation.}, number={4}, journal={BIOTROPICA}, author={Carlo, TA and Collazo, JA and Groom, MJ}, year={2004}, month={Dec}, pages={602–614} }
 @article{herring_collazo_2004, title={Winter survival of lesser scaup in east-central Florida}, volume={68}, ISSN={["1937-2817"]}, DOI={10.2193/0022-541X(2004)068[1082:WSOLSI]2.0.CO;2}, abstractNote={Abstract The North American continental population of lesser scaup (Aythya affinis) has been declining since the mid-1980s. Seasonal survival estimates may provide insights about the ecological basis for this decline, but such data are not available. We estimated post-harvest winter survival of lesser scaup in east-central Florida, USA, where 62% of the Atlantic Flyway population winters. The Kaplan-Meier survival estimate from 11 January to 14 March 2002 was 0.95 ± 0.04 (SE) for females and 0.90 ± 0.09 for males. These estimates were not different (P = 0.64), and pooled survival was 0.93 ± 0.04. Temporary emigration (movement out of and return to the study area) was exhibited by 25% of the birds during survey periods, but absences were short and were believed to have had little effect on precision of survival estimates. Our findings suggested that natural mortality at Merritt Island National Wildlife Refuge (MINWR) and surrounding estuarine areas was relatively low. Our results also indicate that habitat quality in this portion of east-central Florida was sufficient to meet overwintering requirements and likely contributed to the reported survival rates. Estimating survival during other stages of the annual cycle, as well as an overall winter estimate reflecting harvest mortality, is necessary to determine whether low survival rates are responsible for continental population declines.}, number={4}, journal={JOURNAL OF WILDLIFE MANAGEMENT}, author={Herring, G and Collazo, JA}, year={2004}, month={Oct}, pages={1082–1087} }
 @article{carlo_collazo_groom_2003, title={Avian fruit preferences across a Puerto Rican forested landscape: pattern consistency and implications for seed removal}, volume={134}, ISSN={["1432-1939"]}, DOI={10.1007/s00442-002-1087-1}, abstractNote={Avian fruit consumption may ensure plant reproductive success when frugivores show consistent preference patterns and effectively remove and disperse seeds. In this study we examined avian fruit preferences and their seed-removal services at five study sites in north-central Puerto Rico. At each site, we documented the diet of seven common fruit-eating avian species from February to September 1998. Using foraging observations and area-based estimates of fruit abundance, we examined preference patterns of birds. We found that 7 out of 68 fleshy-fruited plant species were responsible for most of the fruit diet of birds. Seventeen plant species were preferred and four of them were repeatedly preferred across several study sites and times by at least one avian species. Preferred plant species comprised a small percentage of fleshy fruits at each site (<15% in four out of five study sites), but showed extended phenology patterns. The quantity of seeds removed by frugivore species was not strictly related to preferences. Some frugivores showing no preference could effectively remove more seeds from plants at some locations than species exhibiting constancy in their patterns of preference. Only two frugivores, Euphonia musica and Vireo altiloquous, removed most of the seeds of plants for which they exhibited repeated preference across the landscape. Preference patterns, particularly those exhibiting consistency in space and time for plant species having prolonged fruiting periods, may have important mechanistic consequences for the persistence, succession, and regeneration of tropical plant communities.}, number={1}, journal={OECOLOGIA}, author={Carlo, TA and Collazo, JA and Groom, MJ}, year={2003}, month={Jan}, pages={119–131} }
 @article{tripp_collazo_2003, title={Density and distribution of water boatmen and brine shrimp at a major shorebird wintering area in Puerto Rico}, volume={11}, ISSN={["1572-9834"]}, DOI={10.1023/b:wetl.0000005542.46697.1d}, number={5}, journal={WETLANDS ECOLOGY AND MANAGEMENT}, author={Tripp, Kimberly J. and Collazo, Jaime A.}, year={2003}, month={Oct}, pages={331–341} }
 @article{collazo_white_vilella_guerrero_2003, title={Survival of captive-reared Hispaniolan parrots released in Parque Nacional del Este, Dominican Republic}, volume={105}, ISSN={["0010-5422"]}, DOI={10.1650/0010-5422(2003)105[0198:SOCHPR]2.0.CO;2}, abstractNote={Abstract We report first-year survival rates of 49 captive-reared Hispaniolan Parrots (Amazona ventralis) released in Parque Nacional del Este, Dominican Republic. Our goal was to learn about factors affecting postrelease survival. Specifically, we tested if survival was related to movements and whether modifying prerelease protocols influenced survival rates. We also estimated survival in the aftermath of Hurricane Georges (22 September 1998). Twenty-four parrots, fitted with radio-transmitters, were released between 14 September and 12 December 1997. Twenty-five more were released between 29 June and 16 September 1998. First-year survival rates were 30% in 1997 and 29% in 1998. Survival probability was related to bird mobility. In contrast to birds released in 1997, none of the 25 parrots released in 1998 suffered early postrelease mortality (i.e., 3–5 days after release). Two adjustments to prerelease protocols (increased exercise and reduced blood sampling) made in 1998 may have contributed to differences in mobility and survival between years. The reduction of early postrelease mortality in 1998 was encouraging, as was the prospect for higher first-year survival (e.g., 30% to 65%). Only one death was attributed to the immediate impact of the hurricane. Loss of foraging resources was likely a major contributor to ensuing mortality. Birds increased their mobility, presumably in search of food. Survival rates dropped 23% in only eight weeks posthurricane. This study underscores the value of standardized prerelease protocols, and of estimating survival and testing for factors that might influence it. Inferences from such tests will provide the best basis to make adjustments to a release program. Supervivencia de Amazona ventralis Criadas en Cautivero y Liberadas en el Parque Nacional del Este, República Dominicana Resumen. Determinamos la supervivencia de 49 individuos de Amazona ventralis criados en cautiverio y liberados en el Parque Nacional del Este, República Dominicana. El proyecto se diseñó para aprender sobre los factores que pueden influenciar la supervivencia de las cotorras dominicanas. Específicamente, pusimos a prueba si la supervivencia estaba relacionada a movimientos y si modificaciones al protocolo de pre-liberación influenciaron la supervivencia. También estimamos la supervivencia de las cotorras después del paso del huracán Georges el 22 de septiembre 1998. En 1997 se liberaron 24 cotorras con radio transmisores entre el 14 de septiembre y el 12 de diciembre. Otras 25 se liberaron entre el 29 de junio y el 16 de septiembre de 1998. La estimación de la supervivencia en 1997 fue de un 30% y en 1998 de un 29%. La probabilidad de supervivencia estuvo relacionada a la movilidad del ave. En comparación con las cotorras liberadas en 1997, ninguna de las cotorras liberadas en 1998 murió durante los primeros 3–5 dias post-liberación. Dos ajustes a los protocolos de pre-liberación en 1998 contribuyeron probablamente a las diferencias en movilidad y supervivencia entre años. Este resultado fue alentador, así como el prospecto de alcanzar tasas más altas de supervivencia (e.g., 30% a 65%). La muerte de sólo una cotorra se atribuye al impacto directo del huracán. La pérdida de recursos alimenticios probablemente contribuyó fuertemente a la mortandad subsiguiente. Las cotorras exhibieron mayor movilidad, presumiblemente en búsqueda de frutos. La tasa de supervivencia disminuyó un 23% en solo ocho semanas después del huracán. Este estudio enfatiza el valor de protocolos de preliberación estandarizados y de estimaciones de tasas de supervivencia que ponen a prueba factores que la puedan influenciar. Las inferencias de dichas pruebas proveerán un mejor fundamento para ajustar los programas de liberación.}, number={2}, journal={CONDOR}, author={Collazo, JA and White, TH and Vilella, FJ and Guerrero, SA}, year={2003}, month={May}, pages={198–207} }
 @article{dinsmore_collazo_2003, title={The influence of body condition on local apparent survival of spring migrant Sanderlings in coastal North Carolina}, volume={105}, ISSN={["0010-5422"]}, DOI={10.1650/7226}, abstractNote={Abstract Many shorebirds are long-distance migrants, and they depend upon widely spaced stopover sites for refueling during their annual migrations. Two competing hypotheses attempt to explain stopover duration: one predicts departure based on time minimization (time-selection hypothesis) and the other predicts departure on the basis of maximum energy gain (energy-selection hypothesis). During spring 1993, we tested these hypotheses during a mark-resight study of migrant Sanderlings (Calidris alba) at Portsmouth Island, North Carolina. We individually color-banded 204 Sanderlings and used capture-recapture methods to estimate local apparent survival during 10 five-day intervals from late April to mid-June. We found that survival rates were best modeled as a decreasing quadratic time trend; a linear time trend and period-specific survival rates received little support. We found no evidence that either body mass or a simple body condition index better explained survival rates. Our estimates of the 5-day local survival rates of Sanderlings at Portsmouth Island remained relatively high (ϕi > 0.80) through late May, after which they dropped rapidly as birds left the area. The period-specific conditional resighting probability was 0.39 (SE = 0.03). Our results do not provide strong support for either the time- or energy-selection hypotheses and hint that studies of migratory behavior need to be conducted even more intensively and across much larger regions in order to better understand the underlying factors. Influencia de la Condición Física sobre las Tasas de Residencia de Calidris alba durante la Migración de Primavera en la Costa de Carolina del Norte Resumen. Muchos playeros migran largas distancias y dependen de áreas ampliamente esparcidas para hacer escalas durante sus migraciones anuales. En estas áreas, los playeros reabastecen rápidamente sus reservas energéticas antes de partir hacia la próxima parada. Existen dos hipótesis principales para explicar la duración de cada escala: una predice que la duración de cada escala es en función de poder minimizar el tiempo (hipótesis de selección temporal) y la otra que el tiempo de escala es determinado sobre la base de maximizar la ganancia de energía (hipótesis de selección energética). Durante la primavera de 1993 pusimos a prueba estas hipótesis durante un estudio sobre captura-recaptura del playero Calidris alba en la Isla de Portsmouth, Carolina del Norte. Marcamos individualmente 204 playeros y usamos el método de captura-recaptura para estimar las tasas de residencia durante 10 intervalos de 5 días entre finales de abril y mediados de junio. Los modelos que mejor explicaron las tasas de residencia revelaron una tendencia cuadrática decreciente. Los datos no apoyaron modelos de tendencia lineal ni tasas de residencia período-específicas. No encontramos evidencia de que el peso corporal ni un índice simple de condición física contribuyesen a explicar mejor las tasas de residencia. Nuestras estimaciones de las tasas de residencia a 5-días para C. alba en la Isla de Portsmouth permanecieron relativamente altas (ϕi > 0.80) durante la segunda mitad de mayo, y disminuyeron rápidamente hasta que los playeros partieron del área. La probabilidad condicional de recuperación visual período-específica fue de 0.39 (EE = 0.03). Nuestros resultados no demostraron evidencia concluyente a favor de ninguna de las dos hipótesis (selección temporal, selección energética). Sugerimos que esta información resalta la necesidad de llevar a cabo estudios detallados a través de regiones geográficamente más amplias para poder entender qué factores explican mejor el comportamiento migratorio.}, number={3}, journal={CONDOR}, author={Dinsmore, SJ and Collazo, JA}, year={2003}, month={Aug}, pages={465–473} }
 @article{collazo_o'hara_kelly_2002, title={Accessible habitat for shorebirds: Factors influencing its availability and conservation implications}, volume={25}, number={2002}, journal={Waterbirds}, author={Collazo, J. A. and O'hara, D. A. and Kelly, C. A.}, year={2002}, pages={13–24} }
 @article{collazo_bonilla-martinez_2001, title={Population size, survival, and movements of White-cheeked Pintails in eastern Puerto Rico}, volume={37}, number={3-4}, journal={Caribbean Journal of Science}, author={Collazo, J. A. and Bonilla-Martinez, G.}, year={2001}, pages={194–201} }
 @article{sallabanks_walters_collazo_2000, title={Breeding bird abundance in bottomland hardwood forests: Habitat, edge, and patch size effects}, volume={102}, DOI={10.2307/1370302}, abstractNote={We studied breeding bird communities in extensive bottomland hardwood forests along the lower Roanoke River in North Carolina during 1992 and 1993. We documented a rich avian community and recorded exceptionally high densities of two species (Prothonotary Warbler Protonotaria citrea, Acadian Flycatcher Empidonax virescens), as well as modest densities of three species rarely encountered elsewhere in the region (Cerulean Warbler Dendroica cerulea, Swainson's Warbler Limnothlypis swainsonii, American Redstart Setophaga ruticilla). The effects of patch size and edge on bird abundance were small in this forested landscape, but forest type had a large effect. We found half of the species analyzed to differ in abundance between the two primary habitat types, swamp forest and levee forest. In contrast, no species was consistently more abundant at patch interiors than near edges, and only two forest birds were more common in large compared with small patches. Species analyzed included permanent residents, short-distance migrants, Neotropical migrants, and those identified as forest-interior and area-sensitive species in other studies. Our results suggest that the Roanoke River bottomland forests may be functioning effectively as a reserve for a number of bird species.}, number={4}, journal={Condor}, author={Sallabanks, R. and Walters, J. R. and Collazo, Jaime}, year={2000}, pages={748–758} }
 @article{saracco_collazo_1999, title={Predation on artificial nests along three edge types in a North Carolina bottomland hardwood forest}, volume={111}, number={4}, journal={Wilson Bulletin}, author={Saracco, J. F. and Collazo, J. A.}, year={1999}, pages={541–549} }
 @article{collazo_agardy_klaas_saliva_pierce_1998, title={An interdecadal comparison of population parameters of Brown Pelicans in Puerto Rico and the US Virgin Islands}, volume={21}, ISSN={["0738-6028"]}, DOI={10.2307/1521731}, number={1}, journal={COLONIAL WATERBIRDS}, author={Collazo, JA and Agardy, T and Klaas, EE and Saliva, JE and Pierce, J}, year={1998}, pages={61–65} }
 @article{conomy_collazo_dubovsky_fleming_1998, title={Dabbling duck behavior and aircraft activity in coastal North Carolina}, volume={62}, ISSN={["0022-541X"]}, DOI={10.2307/3802567}, abstractNote={Requests to increase military aircraft activity in some training facilities in the United States have prompted the need to determine if waterfowl and other wildlife are adversely affected by aircraft disturbance. We quantified behavioral responses of wintering American black ducks (Anas rubripes), American wigeon (A. americana), gadwall (A. strepera), and American green-winged teal (A. crecca carolinensis) exposed to low-level flying military aircrafts at Piney and Cedar islands, North Carolina, in 1991 and 1992. Waterfowl spent ≤1.4% of their time responding to aircraft, which included flying, swimming, and alert behaviors. Mean duration of responses by species ranged from 10 to 40 sec. Costs to each species were deemed low because disruptions represented a low percentage of their time-activity budgets, only a small proportion of birds reacted 'to disturbance (13/672; 2%), and the likelihood of resuming the activity disrupted by an aircraft disturbance event was high (64% ). Recorded levels of aircraft disturbance (i.e., x = 85.1 dBA) were not adversely affecting the time-activity budgets of selected waterfowl species wintering at Piney and Cedar islands.}, number={3}, journal={JOURNAL OF WILDLIFE MANAGEMENT}, author={Conomy, JT and Collazo, JA and Dubovsky, JA and Fleming, WJ}, year={1998}, month={Jul}, pages={1127–1134} }
 @article{conomy_dubovsky_collazo_fleming_1998, title={Do black ducks and wood ducks habituate to aircraft disturbance?}, volume={62}, ISSN={["0022-541X"]}, DOI={10.2307/3802568}, abstractNote={Requests to increase military aircraft activity in some training facilities in the United States have raised the need to determine if waterfowl and other wildlife are adversely affected by aircraft disturbance. We hypothesized that habituation was a possible proximate factor influencing the low proportion of free-ranging ducks reacting to military aircraft activities in a training range in coastal North Carolina during winters 1991 and 1992. To test this hypothesis, we subjected captive, wild-strain American black ducks (Anas rubripes) and wood ducks (Aix sponsa) to actual and simulated activities of jet aircraft. In the first experiment, we placed black ducks in an enclosure near the center of aircraft activities on Piney Island, a military aircraft target range in coastal North Carolina. The proportion of times black ducks reacted (e.g., alert posture, fleeing response) to visual and auditory aircraft activity decreased from 38 to 6% during the first 17 days of confinement. Response rates remained stable at 5.8% thereafter. In the second experiment, black ducks and wood ducks were exposed to 6 different recordings of jet noise. The proportion of times black ducks reacted to noise decreased (P 0.05) in time-activity budgets of black ducks between pre-exposure to noise and 24 hr after first exposure. Unlike black ducks, wood duck responses to jet noise did not decrease uniformly among experimental groups following initial exposure to noise (P = 0.01). We conclude that initial exposure to aircraft noise elicits behavioral responses from black ducks and wood ducks. With continued exposure of aircraft noise, black ducks may become habituated. However, wood ducks did not exhibit the same pattern of response, suggesting that the ability of waterfowl to habituate to aircraft noise maybe species specific.}, number={3}, journal={JOURNAL OF WILDLIFE MANAGEMENT}, author={Conomy, JT and Dubovsky, JA and Collazo, JA and Fleming, WJ}, year={1998}, month={Jul}, pages={1135–1142} }
 @article{dinsmore_collazo_walters_1998, title={Seasonal numbers and distribution of shorebirds on North Carolina's Outer Banks}, volume={110}, number={2}, journal={Wilson Bulletin}, author={Dinsmore, S. J. and Collazo, J. A. and Walters, J. R.}, year={1998}, pages={171–181} }
 @article{miranda_collazo_1997, title={A modified throw-trap to sample prey for wading bird studies}, volume={68}, number={4}, journal={Journal of Field Ornithology}, author={Miranda, L. and Collazo, J. A.}, year={1997}, pages={602–606} }
 @article{braun_epperly_collazo_1997, title={Evaluation of a sonic telemetry system in three habitats of an estuarine environment}, volume={212}, ISSN={["0022-0981"]}, DOI={10.1016/S0022-0981(96)02737-2}, abstractNote={A directional sonic telemetry system in small embayment, seagrass, and channel habitats in Core Sound, North Carolina was evaluated. We compared point location estimates calculated after correcting for system bias in three different ways: using test station (i.e. known location transmitting–receiving stations) angle errors, and using a within test site and an among test site mean angle error estimate. Estimates are necessary because, when tracking an animal, system bias cannot be corrected for using test station angle errors. In addition, telemetered animals may move beyond test areas or into different habitats. We found no significant difference (P>0.05) among point location estimates, suggesting that a within or an among mean angle error was an acceptable estimate. Choosing the appropriate angle error estimate must be done carefully because both presented limitations. A within test site mean angle error was the more conservative approach, avoiding biases caused by significant (P<0.05) interhabitat angle error variability. An estimate containing interhabitat variability (i.e. among test site angle error) might be more robust for correcting system bias when the instrumented animal moves outside test areas or into a heterogeneous area. Seagrass habitat polygons in southern Core Sound range in size from 0.1 to 3189 ha. Attained levels of accuracy and precision from this study suggest that work could be conducted in areas where polygons are ≥6.9 ha, which represents >97% of the seagrass habitat in Core Sound. Although the majority (80%) of the polygons are small (<10.0 ha), they represent <5% of the total seagrass area. In addition, classifying use of habitat in areas where polygons are ≤6.9 ha is possible because small polygons have a contagious distribution; hence, their areas may be additive. Risks of misclassifying use of habitat can be reduced also by controlling the size of confidence areas (Ae) by adjusting the distance between observers and the tracked animal. The confidence area as a function of distance can be predicted because location error varied linearly and significantly with geometric mean distance (Dg). On the basis of this relationship, Dg must be <326 m for Ae95 to be <10.0 ha.}, number={1}, journal={JOURNAL OF EXPERIMENTAL MARINE BIOLOGY AND ECOLOGY}, author={Braun, J and Epperly, SP and Collazo, JA}, year={1997}, month={May}, pages={111–121} }
 @article{miranda_collazo_1997, title={Food habits of 4 species of wading birds (Ardeidae) in a tropical mangrove swamp}, volume={20}, ISSN={["0738-6028"]}, DOI={10.2307/1521591}, number={3}, journal={COLONIAL WATERBIRDS}, author={Miranda, L and Collazo, JA}, year={1997}, pages={413–418} }
 @article{tripp_collazo_1997, title={Non-breeding territoriality of semipalmated sandpipers}, volume={109}, number={4}, journal={Wilson Library Bulletin}, author={Tripp, K. J. and Collazo, J. A.}, year={1997}, pages={630–642} }