@article{kuefler_hudgens_haddad_morris_thurgate_2010, title={The conflicting role of matrix habitats as conduits and barriers for dispersal}, volume={91}, DOI={10.1890/09-0614.1}, abstractNote={Determining connectivity within complex landscapes is difficult if habitats that facilitate dispersal differ from habitats where animals normally are found or enter. We addressed the question of how landscape features affect dispersal by quantifying two critical aspects of animal movement behavior that determine dispersal rates across complex landscapes: conductivity of major habitat types and behavior at boundaries between habitat types. Our tests consisted of behavioral experiments and observational surveys of a wetland butterfly,Satyrodes appalachia. Displacement rates varied among habitats, with the longest moves and straightest paths leading to greater displacement rate in open habitat and shortest moves and most sinuous paths causing the slowest displacement rate in riparian forest habitat. We found a strong negative relationship between the probability of entering a habitat and the speed of moving through it. Recognizing this central conflict between entering and moving through habitat is important for assessing the connectivity of complex landscapes.}, number={4}, journal={Ecology (Brooklyn, New York, N.Y.)}, author={Kuefler, D. and Hudgens, B. and Haddad, N. M. and Morris, W. F. and Thurgate, N.}, year={2010}, pages={944–950} }
 @article{haddad_hudgens_damiani_gross_kuefler_pollock_2008, title={Determining optimal population monitoring for rare butterflies}, volume={22}, ISSN={["1523-1739"]}, DOI={10.1111/j.1523-1739.2008.00932.x}, abstractNote={Abstract: Determining population viability of rare insects depends on precise, unbiased estimates of population size and other demographic parameters. We used data on the endangered St. Francis' satyr butterfly (Neonympha mitchellii francisci) to evaluate 2 approaches (mark–recapture and transect counts) for population analysis of rare butterflies. Mark–recapture analysis provided by far the greatest amount of demographic information, including estimates (and standard errors) of population size, detection, survival, and recruitment probabilities. Mark–recapture analysis can also be used to estimate dispersal and temporal variation in rates, although we did not do this here. Models of seasonal flight phenologies derived from transect counts (Insect Count Analyzer) provided an index of population size and estimates of survival and statistical uncertainty. Pollard–Yates population indices derived from transect counts did not provide estimates of demographic parameters. This index may be highly biased if detection and survival probabilities vary spatially and temporally. In terms of statistical performance, mark–recapture and Pollard–Yates indices were least variable. Mark–recapture estimates were less likely to fail than Insect Count Analyzer, but mark–recapture estimates became less precise as sampling intensity decreased. In general, count‐based approaches are less costly and less likely to cause harm to rare insects than mark–recapture. The optimal monitoring approach must reconcile these trade‐offs. Thus, mark–recapture should be favored when demographic estimates are needed, when financial resources enable frequent sampling, and when marking does not harm the insect populations. The optimal sampling strategy may use 2 sampling methods together in 1 overall sampling plan: limited mark–recapture sampling to estimate survival and detection probabilities and frequent but less expensive transect counts.}, number={4}, journal={CONSERVATION BIOLOGY}, author={Haddad, Nick M. and Hudgens, Brian and Damiani, Chris and Gross, Kevin and Kuefler, Daniel and Pollock, Ken}, year={2008}, month={Aug}, pages={929–940} }
 @article{kuefler_haddad_hall_hudgens_bartel_hoffman_2008, title={Distribution, population structure and habitat use of the endangered Saint Francis Satyr butterfly, Neonympha mitchellii francisci}, volume={159}, ISSN={["1938-4238"]}, DOI={10.1674/0003-0031(2008)159[298:DPSAHU]2.0.CO;2}, abstractNote={ABSTRACT The endangered St. Francis Satyr (Neonympha mitchellii francisci) is a small sedentary butterfly and one of the rarest in North America. Our study examined various quantitative aspects of this butterfly's biology, including the distributional range, habitat associations, population size and trends, demographic parameters and spatial aspects of population structure. The range of N.m. francisci distribution is restricted to DoD lands at Ft. Bragg, North Carolina, where the butterfly utilizes wetland habitats, predominantly those that have previously been impounded by beaver. In situ habitat associations and captive rearing experiments indicate that multiple sedges in the genus Carex, particularly C. mitchelliana, may be important larval food plants. Subpopulation estimates range between 49–739 individuals at any one site, while cumulative population estimates range between 700–1400 individuals for all accessible areas on Ft. Bragg. Habitats occupied by N.m. francisci are frequently subject to burning or flooding and thus butterfly subpopulations are extremely dynamic, fluctuating in response to these disturbances. This regular disturbance regime dictates that dispersal is necessary for population persistence. Several inter-colony movements were measured during capture-recapture studies and we observed both subpopulation extinctions and colonization of new habitat through the period of our studies. Conservation of N.m. francisci depends on accommodating unique aspects of its populations, including its dependence on beaver and its multi-tiered metapopulation structure.}, number={2}, journal={AMERICAN MIDLAND NATURALIST}, author={Kuefler, Daniel and Haddad, Nick M. and Hall, Stephen and Hudgens, Brian and Bartel, Becky and Hoffman, Erich}, year={2008}, month={Apr}, pages={298–320} }
 @article{kuefler_haddad_2006, title={Local versus landscape determinants of butterfly movement behaviors}, volume={29}, ISSN={["1600-0587"]}, DOI={10.1111/j.0906-7590.2006.04574.x}, abstractNote={Large‐scale patterns of animal distributions and abundances may be determined by mechanisms that act at local or landscape scales. We studied the movement behaviors of four species of bottomland butterflies in a natural setting to examine the determinants of movement behavior across different scales. We tested the relative importance of three landscape attributes: drainage slope, boundary type, and stream proximity, and local habitat attributes related to food plants and plants that influence habitat structure. Across species, we tested the relative importance of organism size and habitat specificity to explain response variation. In general, butterfly responses to landscape features were more universal than responses to local features. Specifically, results from this study showed that drainage slope did not influence movement behaviors but boundary type, stream proximity, and host plant abundance all influenced movement patterns. Responses to local features varied by species and often complemented landscape effects on movement. Responses to all features were not related to butterfly size, but did vary in accordance with butterfly host plant specificity. These behaviors help to explain landscape‐level variation in population distribution among species.}, number={4}, journal={ECOGRAPHY}, author={Kuefler, Daniel and Haddad, Nick M.}, year={2006}, month={Aug}, pages={549–560} }
 @article{bradley_damschen_young_kuefler_went_wray_haddad_knops_louda_2003, title={Spatial heterogeneity, not visitation bias, dominates variation in herbivory}, volume={84}, ISSN={["0012-9658"]}, DOI={10.1890/02-3082}, abstractNote={Experiments in ecology can have unintended side effects. Recently, it has been suggested that the act of visiting a plant, inherent to studying herbivory, may alter plant performance and interactions. To evaluate the generality of this inference, we examined plant performance and herbivory on 14 plant species in three geographic regions. Visitation did not significantly affect any of the variables that we measured, including leaf damage, height, biomass, or survivorship, for any species. However, rates of herbivory varied significantly among sites and regions. Thus, our data do not support the generality of visitation impacting estimates of herbivory. We propose that future studies of herbivory will gain more by evaluating spatial heterogeneity in interaction outcomes than by quantifying possible experimenter-caused variation.}, number={8}, journal={ECOLOGY}, author={Bradley, KL and Damschen, EI and Young, LM and Kuefler, D and Went, S and Wray, G and Haddad, NM and Knops, JMH and Louda, SM}, year={2003}, month={Aug}, pages={2214–2221} }