Digital Commons Network^™

Estimating Northern Spotted Owl (Strix Occidentalis Caurina) Pair Detection Probabilities Based On Call-Back Surveys Associated With Long-Term Mark-Recapture Studies, 1993–2018, Katie M. Dugger, Alan B. Franklin, Damon B. Lesmeister, Raymond J. Davis, J. David Wiens, Gary C. White, James D. Nichols, James E. Hines, Charles B. Yackulic, Carl J. Schwarz, Steven A. Ackers, L. Steven Andrews, Larissa L. Bailey, Robin Bown, Jesse Burgher, Kenneth P. Burnham, Peter C. Carlson, Tara Chestnut, Mary M. Conner, Krista E. Dilione, Eric D. Forsman, Scott A. Gremel, Keith A. Hamm, Dale R. Herter, J. Mark Higley, Rob B. Horn, Julianna M. Jenkins, William L. Kendall, David W. Lapmphear, Christopher Mccafferty, Trent L. Mcdonald, Janice A. Reid, Jeremy T. Rockweit, David C. Simon, Stan G. Sovern, James K. Swingle, Heather Wise

United States Department of Agriculture Wildlife Services: Staff Publications

The northern spotted owl (Strix occidentalis caurina; hereinafter NSO) was listed as “threatened” under the Endangered Species Act in 1990 and population declines have continued since that listing. Given the species’ protected status, any proposed activities on Federal lands that might impact NSO require consultation with U.S. Fish and Wildlife Service and part of that consultation often includes surveys to determine presence and occupancy status of the species in the proposed activity area. The objective of this report is to present study-area specific estimates of the probability of detection for NSO pairs from twelve 2-week seasonal survey periods …

Light Wavelength And Pulsing Frequency Affect Avoidance Responses Of Canada Geese, Ryan B. Lunn, Patrice E. Baumhardt, Bradley F. Blackwell, Jean Paul Freyssinier, Esteban Fernández-Juricic

United States Department of Agriculture Wildlife Services: Staff Publications

Collisions between birds and aircraft cause bird mortality, economic damage, and aviation safety hazards. One proposed solution to increasing the distance at which birds detect and move away from an approaching aircraft, ultimately mitigating the probability of collision, is through onboard lighting systems. Lights in vehicles have been shown to lead to earlier reactions in some bird species but they could also generate attraction, potentially increasing the probability of collision. Using information on the visual system of the Canada goose (Branta canadensis), we developed light stimuli of high chromatic contrast to their eyes. We then conducted a controlled …

Risk Of African Swine Fever Virus Transmission Among Wild Boar And Domestic Pigs In Poland, Kim M. Pepin, Tomasz Borowik, Maciej Frant, Kamila Plis, Tomasz Podgórski

United States Department of Agriculture Wildlife Services: Staff Publications

Introduction

African swine fever (ASF) is a notifiable disease of swine that impacts global pork trade and food security. In several countries across the globe, the disease persists in wild boar (WB) populations sympatric to domestic pig (DP)operations, with continued detections in both sectors. While there is evidence of spillover and spillback between the sectors, the frequency of occurrence and relative importance of different risk factors for transmission at the wildlife-livestock interface remain unclear.

Methods

To address this gap, we leveraged ASF surveillance data from WB and DP across Eastern Poland from 2014–2019 in an analysis that quantified the relative …

Changes In Fecal Glucocorticoid Metabolites In Captive Coyotes (Canis Latrans): Influence Of Gender, Time, And Reproductive Status, Eric M. Gese, Patricia A. Terletzky, Cole A. Bleke, Erika T. Stevenson, Susannah S. French

United States Department of Agriculture Wildlife Services: Staff Publications

Simple summary

Biologists have long considered producing offspring a demanding time in the life of any animal, with reproducing and raising offspring being physiologically stressful. We examined whether breeding and producing pups was more stressful than other life-history stages among captive coyotes (Canis latrans) using fecal sampling and subsequent assays for glucocorticoid metabolites. Using 12 pairs of coyotes (five pairs produced pups, seven pairs did not), we examined fecal glucocorticoid metabolites (fGCM) covering 11 biological time periods for one year. We found high individual variability among both females and males with no apparent statistical effect of reproduction on …

Differential Canid Predation Of Translocated Juvenile Desert Tortoises (Gopherus Agassizii) Using Chemical Signature Differences, Derek B. Hall, Bruce A. Kimball, Jennifer M. Germano, Eric M. Gese, Jeanette A. Perry

United States Department of Agriculture Wildlife Services: Staff Publications

Differential predation was observed in a population of 59 translocated juvenile desert tortoises (Gopherus agassizii) of known sex during a juvenile translocation survival study between September 2012 and November 2017. The main source of mortality was attributed to coyote (Canis latrans) and kit fox (Vulpes macrotis) predation. Predation was skewed with higher female mortality than male mortality. We tested the hypothesis that juvenile females smell different than males, which leads to increased canid predation. We also explored differences in chemical signatures of resident adult female and male desert tortoises. We collected oral, cloacal, and …

Assessing The Efficacy Of Beaver Dam Analogs In Willow Restoration, Hannah Hill, Dylan Ritter

Undergraduate Theses, Professional Papers, and Capstone Artifacts

Willow establishment is a necessary objective of stream restoration due to their role in bank stabilization, stream shading, and enhancement of biodiversity across the riparian zone. However, anecdotal observation indicated that establishment on beaver dam analogue (BDA) restored streams may be lacking. BDA’s mimic the pooling effects of natural beaver structures and are intended to help recreate historic conditions that existed before beaver extirpation. When working as intended, ecosystem function is restored, and a major aspect of this is willow presence. Because of these observations, as well as limited information on willow recruitment following restoration, we ask the following questions. …

Out Of The Frying Pan And Into The Fire: How Hunting Affects The Diel Activity Patterns Of Ungulates In Lubrecht Experimental Forest, Shawn M. Parsons

Undergraduate Theses, Professional Papers, and Capstone Artifacts

Predator-prey dynamics shape diel activity patterns of large mammals. The avoidance of predation risk by prey in both space and time can affect predator-prey overlap and reduce risk of mortality. Here, I examined if rifle hunting affected the diel activity patterns of ungulates and their primary predator, pumas, in Lubrecht Experimental Forest, Montana. I deployed 30 infrared wildlife remote cameras across 29 sites using a stratified random design over three months before, during, and after the Fall 2022 Montana rifle hunting season. This project was also part of the Snapshot USA 2022 initiative. Using timestamps from these photos, daily activity …

Two Research Perspectives On Sugar Maple Canopy Dieback In The Upper Great Lakes: A Decade Of Herbaceous Community Responses And A Survey Of Michigan Forest Managers, Manuel Eduardo Anderson

Dissertations, Master's Theses and Master's Reports

Sugar maple canopy dieback has been reported in the upper Great Lakes since the mid-2000s. This thesis builds on research conducted to determine some of the underlying causes of canopy dieback, which include invasive earthworm impacts, with a view toward adaptations in management of northern hardwood forests in our region. The first chapter reports a study of understory communities in a subsection of forest health monitoring plots located in four national forests near Lake Superior. Based on plot assessments from 2010 and 2021, responses of plant community composition and traits to earthworm impacts and sugar maple canopy dieback were explored. …

Land Systems, Soils And Vegetation Of The Southern Goldfields And Great Western Woodlands Of Western Australia - Volume 1, Peter-Jon A. Waddell, Paul Galloway

Technical Bulletins

This technical bulletin defines and maps the land resources of the southern Goldfields region of Western Australia (WA). The southern Goldfields region, as featured in this bulletin, covers 151,753 km². The western and eastern borders are variable because they align with various cadastral boundaries. The western survey border, which in part follows the WA State Barrier Fence, demarcates cleared agricultural land from the intact, western extent of the Great Western Woodlands. The eastern border abuts the westernmost Nullarbor pastoral lease boundaries, except for the north-easternmost and south-easternmost edges which continue into Crown land. Major towns are Coolgardie, Kalgoorlie …

Land Systems, Soils And Vegetation Of The Southern Goldfields And Great Western Woodlands Of Western Australia - Volume 2, Peter-Jon A. Waddell, Paul Galloway

Technical Bulletins

This technical bulletin defines and maps the land resources of the southern Goldfields region of Western Australia (WA). The southern Goldfields region, as featured in this bulletin, covers 151,753 km². The western and eastern borders are variable because they align with various cadastral boundaries. The western survey border, which in part follows the WA State Barrier Fence, demarcates cleared agricultural land from the intact, western extent of the Great Western Woodlands. The eastern border abuts the westernmost Nullarbor pastoral lease boundaries, except for the north-easternmost and south-easternmost edges which continue into Crown land. Major towns are Coolgardie, Kalgoorlie …

Placing The Evolutionary History Of Desmognathus Salamanders In Context: A Phylogeographic Approach, Kara Jones

Theses and Dissertations--Biology

Patterns of genetic variation do not arise in a vacuum but are instead shaped by the interplay between evolutionary forces and ecological constraints. Here, I use a phylogeographic approach to examine the role that ecology played in lineage divergence in the Desmognathus quadramaculatus species complex (Family: Plethodontidae), which consists of three nominal species: D. quadramaculatus, D. marmoratus, and D. folkertsi. Previous phylogenetic studies have shown that individuals from these species do not form clades based on phenotype. My approach to reconciling phylogenetic discordance was two-fold, using (1) genome-wide markers to provide insight into the …

Competition And Herbivory Influence The Survival, Growth, And Physiology Of Native Tree Seedlings In The Kentucky Inner Bluegrass Savanna-Woodland, James D. Shaffer

Theses and Dissertations--Biology

Terrestrial plant communities are shaped by competition for resources, herbivory, and abiotic processes. Savanna systems represent a dynamic coexistence of contrasting life forms (grasses and trees) shaped by competition and disturbance. The Kentucky Inner Bluegrass Savanna-Woodland (KIBSW) is described as an open woodland of shade intolerant species; however, climatic, and edaphic conditions can support closed-canopy forest. After European pioneer settlement (c1750-1800), over 99% of “savanna-woodlands” have been lost. KIBSW remnants are experiencing a recruitment failure, leading to a dominance shift in tree communities. I researched how tree-grass competition and mammalian herbivory influence KIBSW regeneration and maintenance. The KIBSW does not …

Context-Dependency And Sex-Specificity Of Dispersal Syndromes, Allyssa Kilanowski

Theses and Dissertations--Biology

For populations in landscapes with increasingly heterogeneous and fragmented habitat patches (e.g., metapopulations), dispersal is an important behavior that leads to gene flow and connectivity among isolated patches. Because dispersal is a complex process, there are many traits involved. When suites of morphological, behavioral, physiological, and life-history traits covary with dispersal (e.g., a dispersal syndrome), the correlated traits can assist dispersing individuals through the complex process. Furthermore, once dispersal is completed, the correlated traits can influence the fitness of those dispersed individuals. Dispersal syndromes will likely interact with the local environment to produce ecological and evolutionary feedbacks on the metapopulation. …

Parental Effects On Offspring Reaction Norms: Consequences For Complex Phenotypes In Variable Environments, Alexandra G. Cones

Theses and Dissertations--Biology

Organismal traits all exhibit some degree of environmental sensitivity, and both the strength and direction of these phenotypically plastic responses to the environment can evolve in adaptive ways. For example, parents can use information about their own environment to precondition the traits of their offspring so that they thrive in their future environment. This transgenerational plasticity can also alter the plasticity of offspring, but explicit investigations of this specific phenomenon are rare. I begin with a review of the literature and provide a quantitative genetic framework to investigate this phenomenon, which I then explore empirically using avian embryos. The metabolic …

Multilevel Phenotypic Integration Of Metabolism And Behavior In House Sparrows And Mice, Tim Salzman

Theses and Dissertations--Biology

Patterns of multilevel variation in behavior, both within and among individuals, raise challenging questions about underlying mechanisms and the selective pressures acting on them. One intriguing hypothesis is that physiology shows parallel multilevel variation, and so might represent a latent trait that integrates multilevel behavioral responses. For example, foraging acquires the fuel needed to maintain metabolism, and in turn, an individual’s metabolism affects expression of foraging, and other, behaviors. Metabolism and behavior thus might coevolve to become integrated traits. Despite the appeal of this hypothesis, numerous investigations into the link between metabolism and behavior have yielded largely equivocal results.

To …

Predicting Mountain Lion Resource Selection And Abundance In North America, William Connor O'Malley

Graduate Student Theses, Dissertations, & Professional Papers

The relationship between habitat quality and density is well documented in lower trophic levels but to what extent it can be extended to higher trophic levels is unknown. I tested the relationship between habitat quality, home-range size and density using a wide-ranging, well-studied, top carnivore, the mountain lion (Puma concolor). First, I created a second-order resource selection function (RSF) for mountain lions in their current North American range using GPS collar data from 476 individuals in 20 study sites and remotely-sensed landscape data. I used the RSF and home range estimates derived from collared animals to quantify mountain …

Helminth And Protozoan Parasites Of Subterranean Rodents (Chordata, Mammalia, Rodentia) Of The World, Altangerel Tsogtsaikhan Dursahinhan, Daniel A. Kenkel, Scott Lyell Gardner

Scott L. Gardner Publications

Published studies and ten new unpublished records included herein reveal that approximately 174 species of endoparasites (helminths and protozoans) are known from 65 of 163 species of rodents that occupy the subterranean ecotope globally. Of those, 94 endoparasite species were originally described from these rodents. A total of 282 host-parasite associations are summarized from four major zoogeographic regions including Ethiopian, Palearctic/Oriental, Nearctic, and Neotropical. Thirty-four parasite records from the literature have been identified to only the level of the genus. In this summary, ten new records have been added, and the most current taxonomic status of each parasite species is …

Intercontinental Comparisons Of Subterranean Host-Parasite Communities Using Bipartite Network Analyses, Altangerel Tsogtsaikhan Dursahinhan, Sebastian Botero-Cañola, Scott L. Gardner

Scott L. Gardner Publications

Rodents living in a subterranean ecotope face a unique combination of evolutionary and ecological pressures and while host species evolution may be driven by the selective pressure from the parasites they harbour, the parasites may be responding to the selective pressures of the host. Here we obtained all available subterranean rodent host-parasite records from the literature and integrated these data by utilizing a bipartite network analysis to determine multiple critical parameters to quantify and measure the structure and interactions of the organisms present in host-parasite communities. A total of 163 species of subterranean rodent hosts, 174 parasite species, and 282 …

“Revisiting The Past”: A Redescription Of Physaloptera Retusa (Nemata, Physalopteridae) From Material Deposited In Museums And New Material From Amazon Lizards = “Revisitando O Passado”: Uma Redescrição De Physaloptera Retusa (Nemata, Physalopteridae) A Partir De Material Depositado Em Museus E Novo Material De Lagartos Amazônicos, Lílian Cristina Macedo, Yuri Willkens, Leandro Maurício Oliveira Da Silva, Scott Lyell Gardner, Francisco Tiago De Vasconcelos Melo, Jeannie Nascimento Dos Santos

Scott L. Gardner Publications

Abstract

Physaloptera Rudolphi, 1819 is a genus of nematodes that includes approximately 100 species parasitic in vertebrates around the world. From these, approximately 30 occur in the Neotropical region, with nine reported from neotropical reptiles. Physaloptera spp. are recognized by their distinct morphology of the apical end and characters of the reproductive system. However, despite the fact that the morphological characters for species diagnosis have been firmly established, we frequently find identification problems regarding poorly detailed descriptions and poorly preserved specimens. These may lead to taxonomic incongruencies. Physaloptera retusa (Rudolphi, 1819) is the most common species of the genus and …

Tapping Into Natural History Collections To Assess Latitudinal Gradients Of Parasite Diversity, Sebastian Botero-Cañola, Scott Lyell Gardner

Scott L. Gardner Publications

Parasites are key components of the biosphere not only due to their huge diversity, but also because they exert important influences on ecological processes. Nevertheless, we lack an understanding of the biogeographical patterns of parasite diversity. Here, we tap into the potential of biodiversity collections for understanding parasite biogeography. We assess species richness of supracommunities of helminth parasites infecting mammal assemblages in the Nearctic, and describe its relation to latitude, climate, host diversity, and land area. We compiled data from parasitology collections and assessed parasite diversity in Nearctic ecoregions for the entire parasite supracommunity of mammals in each ecoregion, as …

Filling The Gap In Distribution Ranges And Conservation Status In Ctenomys (Rodentia: Ctenomyidae), Diego A. Caraballo, Sabrina Laura Lopez, Sebastian Botero-Cañola, Scott Lyell Gardner

Scott L. Gardner Publications

South American subterranean rodents of the genus Ctenomys (Rodentia, Ctenomyidae, tuco-tuco) are one of the most diverse genera among mammals. Recently described species, new taxonomic revisions, and new distribution range delimitation made the revision of distribution areas and conservation status of these mammals mandatory. Implementing the first part of the DAMA protocol (document, assess, monitor, act), here we compile updated sets of species distribution range maps and use these and the number of collection localities to assess the conservation status of ctenomyids. We integrate potential for conservation in protected areas, and levels of habitat transformation to revise previous conservation status …

A New Species Of Mathevotaenia (Cestoda: Anoplocephalidae) From The Andean Tuco-Tuco, Ctenomys Opimus (Rodentia: Ctenomyidae), On The Altiplano Of Bolivia, Scott Lyell Gardner, Bennett A. Grappone, Alex Lai

Scott L. Gardner Publications

A new species of Mathevotaenia Akumyan, 1946 (Cestoda: Anoplocephalidae) is described from the Andean tuco-tuco, Ctenomys opimus Wagner 1848 (Rodentia: Ctenomyidae), collected in 1984 on the Altiplano of Bolivia. This is the second species of anoplocephalid cestode recorded from rodents of the genus Ctenomys, the first being Monoecocestus torresi Olsen 1976 from the Maule tuco-tuco, Ctenomys maulinus Philippi 1872, documented in southwestern Argentina. The new species of Mathevotaenia described here has more testes per segment than any other described species of the same genus from South America. The description of a new species from a decades-old specimen highlights the …

Worldwide Host Associations Of The Tick Genus Ixodes Suggest Relationships Based On Environmental Sharing Rather Than On Co-Phylogenetic Events, Agustín Estrada-Peña, Alberto A. Guglielmone, Santiago Nava

Harold W. Manter Laboratory of Parasitology: Library Materials

Abstract

Background

This study aims to capture how ticks of the genus Ixodes gained their hosts using network constructs. We propose two alternative hypotheses, namely, an ecological background (ticks and hosts sharing environmentally available conditions) and a phylogenetic one, in which both partners co-evolved, adapting to existing environmental conditions after the association took place.

Methods

We used network constructs linking all the known pairs of associations between each species and stage of ticks with families and orders of hosts. Faith’s phylogenetic diversity was used to evaluate the phylogenetic distance of the hosts of each species and changes occurring in the …

Diagnosing Neurocysticercosis In Skeletonized Human Remains Of Forensic Importance, John O. Obafunwa, Karl Reinhard

Karl Reinhard Publications

Neurocysticercosis is endemic in many parts of the underdeveloped and developing countries, with continuous presence in developed countries due to the influx of migrants from regions where the diseases are endemic. Neuroimaging, anatomic pathological techniques, immunodiagnostic tests, clinical examination and epidemiologic considerations will easily provide the diagnosis. However, physicians in developed countries are perhaps progressively missing the diagnosis, and need to re-acquaint themselves with the condition and acquire a high suspicion index. The authors present a medicolegal case where the forensic team made a conclusion of neurocysticercosis (among other diagnoses), following post mortem examination of a largely skeletonized and mummified …

Exploring The Evolution Of Trypanosoma Cruzi And The Emergence Of Chagas Disease In The Context Of Environmental Change: Applying The Stockholm Paradigm To Archaeoparasitology, Part I, Aida Romera Barbera, Daniel R. Brooks, T. Michael Fink, Karl J. Reinhard

Karl Reinhard Publications

The Stockholm Paradigm is an evolutionary synthesis that explains the emergence of novel pathogens in the context of environmental disturbances. Considering the urgent climate change situation, anticipation stands as key to prevent and mitigate the effects that climate change can have in the emergence of pathogens. However, the success of preventive measures is hindered by a limited knowledge of the interplaying dynamics between biology, environment, and culture leading to emerging infectious diseases. For many decades, bioarchaeologists have been gathering data on past human-environment interactions, therefore contributing to the conversation. Archaeoparasitology, at the intersection between pathology, bioarchaeology, and biology, is uniquely …

Documenting The Presence Of Chagas Disease In Prehistoric North America: Applying The Stockholm Paradigm To Archaeoparasitology, Part Ii, Karl J. Reinhard, Daniel R. Brooks, Aida Romera Barbera, T. Michael Fink

Karl Reinhard Publications

The DAMA protocol (Document, Assess, Monitor, Act) is the applied aspect of the Stockholm Paradigm. Evidence from archaeology and history of medicine has a demonstrated value in documenting infection risk for specific study areas. Bioarchaeological remains and historical documents show vivid examples of pathology related to the Chagas disease life cycle. The science of archaeology defines the lifestyles that created risk of triatomine kissing bug infestations and trypanosome protozoa infections. Paleogenetics, in the form of molecular analyses of Trypanosoma cruzi, elucidate the temporal origins of genetic variants and adaptation to human environments. We illustrate how these fields reveal the risk …

Range-Wide Sources Of Variation In Reproductive Rates Of Northern Spotted Owls, Jeremy T. Rockweit, Julianna M. Jenkins, James E. Hines, James D. Nichols, Katie M. Dugger, Alan B. Franklin, Peter C. Carlson, William L. Kendall, Damon B. Lesmeister, Christopher Mccafferty, Steven H. Ackers, L. Steven Andrews, Larissa L. Bailey, Jesse Burgher, Kenneth P. Burnham, Tara Chestnut, Mary M. Conner, Raymond J. Davis, Krista E. Dilione, Eric D. Forsman, Elizabeth M. Glenn, Scott A. Gremel, Keith A. Hamm, Dale R. Herter, J. Mark Higley, Rob B. Horn, David W. Lamphear, Trent L. Mcdonald, Janice A. Reid, Carl J. Schwarz, David C. Simon, Stan G. Sovern, James K. Swingle, J. David Wiens, Heather Wise, Charles B. Yackulic

United States Department of Agriculture Wildlife Services: Staff Publications

We conducted a range-wide investigation of the dynamics of site-level reproductive rate of northern spotted owls using survey data from 11 study areas across the subspecies geographic range collected during 1993–2018. Our analytical approach accounted for imperfect detection of owl pairs and misclassification of successful reproduction (i.e., at least one young fledged) and contributed further insights into northern spotted owl population ecology and dynamics. Both nondetection and state misclassification were important, especially because factors affecting these sources of error also affected focal ecological parameters. Annual probabilities of site occupancy were greatest at sites with successful reproduction in the previous year …

Demographic And Functional Responses Of Kit Foxes To Changes In Prey Abundance, Ashley E. Hodge, Eric M. Gese, Bryan M. Kluever

United States Department of Agriculture Wildlife Services: Staff Publications

Many carnivores exhibit demographic and functional responses to changes in prey abundance. Demographic responses often include changes in population size, litter size, and recruitment of young into the adult population. Functional feeding responses are commonly reported for many carnivore species. We investigated demographic and functional responses of kit foxes (Vulpes macrotis Merriam, 1888) to changes in prey abundance during 2010–2013 in western Utah, USA. Between 2010 and 2013, litter size averaged 3.9 (±1.4) pups/litter. Survival rates of kit fox pups were 0.07, 0.01, 0.46, and 0.16, respectively, and there was a correlation between pup survival rates and rodent abundance; …

Comparison Of An Antioxidant Source And Antioxidant Plus Bcaa On Athletic Performance And Post Exercise Recovery Of Horses, Emily Kent, Stephen J. Coloman, Jason E. Bruemmer, Renan Regatieri Casagrande, Christine Levihn, Grace Romo, Kevin Herkelman, Tanja Hess

United States Department of Agriculture Wildlife Services: Staff Publications

Antioxidant supplementation decreases postexercise oxidative stress but could also decrease muscle pro- tein synthesis. This study compared the effects of three diets: low antioxidant (control, CON), high an- tioxidant (AO), and branched-chain amino acid high antioxidant (BCAO) supplementation on postexercise protein synthesis and oxidative stress. We hypothesized that supplementing antioxidants with branched- chain amino acids(BCAA) would reduce oxidative stress without hindering muscle protein synthesis. Eigh- teen mixed-breed polo horses (11 mares and 7 geldings, with age range between 5 and 18 years, were on CON diet for 30 days (from day -45 until day 0) and then were assigned to …

High Winds And Melting Sea Ice Trigger Landward Movement In A Polar Bear Population Of Concern, Annie Kellner, Todd C. Atwood, David C. Douglas, Stewart W. Breck, Colorado State University - Fort Collins

United States Department of Agriculture Wildlife Services: Staff Publications

Some animal species are responding to climate change by altering the timing of events like mating and migration. Such behavioral plasticity can be adaptive, but it is not always. Polar bears (Ursus maritimus) from the southern Beaufort Sea subpopulation have mostly remained on ice year-round, but as the climate warms and summer sea ice declines, a growing proportion of the subpopulation is summering ashore. The triggers of this novel behavior are not well understood. Our study uses a parametric time-to-event model to test whether biological and/or time-varying environmental variables thought to influence polar bear movement and habitat selection …