Community-based observations were used to model the distribution of Gray Fox (Urocyon cinereoargenteus) in Indiana, United States. While large forest patches greatly influenced overall predicted presence, anthropogenic land cover was influential in the agriculturally dominated landscapes. Gray Fox (Urocyon cinereoargenteus) in Indiana and several other Midwest states have been experiencing a potential population decline and range contraction in recent years. Developing a species distribution model for Gray Fox in Indiana is necessary for identifying target areas for management efforts. For species with cryptic behaviors, such as Gray Fox, advancements in modeling, e.g., maximum entropy modeling (MaxEnt) have allowed for presence-only data to be used effectively to develop species distribution models. Physically surveying a large area for the presence of a cryptic species is difficult, but using community-based observation data (e.g., Archer's Index, harvest data) can allow for creation of a discriminatory species distribution model. Our objective was to use multiple sources of community-based observation data to create a species distribution model of Gray Fox in Indiana using a maximum entropy approach. We developed 12 a priori models containing ecologically relevant covariates (e.g., distance to land-cover type, landscape-patch metrics) and trained (n = 71 observations) and tested (n = 57) each model using community-based observation data that were confirmed by experts. Our best-performing models predicted the highest probabilities of presence of Gray Fox in the northern and southern extents of the state, and relatively low probabilities of presence in the central, agriculture-dominated epicenter of the state. The highest probabilities of presence were associated with greater amounts of forest (mixed and evergreen), urban-forest, and forest-scrub edge. These areas may be the most suitable habitat for Gray Fox due to increased amounts of potential cover and reduced competition from other mesocarnivores. Our results support the importance of maintaining contiguous forest patches or a forest-urban-scrub landscape matrix for Gray Fox populations in Indiana and other midwestern states. Given the dominance of privately owned land in the Midwest, collaboration between managers and landowners is critical for making informed habitat-management decisions for Gray Fox. El zorro gris (Urocyon cinereoargenteus) en Indiana, as & iacute; como en otros estados del Medio Oeste, ha experimentado un potencial declive poblacional y una contracci & oacute;n de su rango de distribuci & oacute;n en los & uacute;ltimos a & ntilde;os. El desarrollo de un modelo de distribuci & oacute;n de especies para el zorro gris en Indiana es necesario para identificar & aacute;reas prioritarias para los esfuerzos de manejo. Para especies con comportamientos cr & iacute;pticos, como el zorro gris, los avances en modelado (por ejemplo, el modelado de m & aacute;xima entrop & iacute;a [MaxEnt]) han permitido utilizar datos de presencia & uacute;nicamente de manera efectiva para generar modelos de distribuci & oacute;n de especies. La prospecci & oacute;n f & iacute;sica de un & aacute;rea extensa para detectar la presencia de una especie cr & iacute;ptica es compleja, pero el uso de datos de observaci & oacute;n comunitaria (por ejemplo, el ndice de Archer, registros de caza) permite la creaci & oacute;n de un modelo de distribuci & oacute;n de especies discriminatorio. Nuestro objetivo fue integrar m & uacute;ltiples fuentes de datos de observaci & oacute;n comunitaria para desarrollar un modelo de distribuci & oacute;n de especies del zorro gris en Indiana utilizando un enfoque de m & aacute;xima entrop & iacute;a. Se desarrollaron 12 modelos a priori que incluyeron covariables ecol & oacute;gicamente relevantes (por ejemplo, distancia a tipos de cobertura del suelo, m & eacute;tricas de parches del paisaje) y se entrenaron (n = 71 observaciones) y evaluaron (n = 57) utilizando datos de observaci & oacute;n comunitaria confirmados por expertos. Los modelos de mejor desempe & ntilde;o predijeron las mayores probabilidades de presencia del zorro gris en los extremos norte y sur del estado, y probabilidades relativamente bajas en el centro del estado, dominado por la agricultura. Las mayores probabilidades de presencia se asociaron con mayores extensiones de bosque (mixto y perenne), bordes bosque-urbano y bosque-matorral. Estas & aacute;reas podr & iacute;an constituir el h & aacute;bitat m & aacute;s adecuado para el zorro gris debido al incremento de refugios potenciales y a la menor competencia con otros mesocarn & iacute;voros. Nuestros resultados respaldan la importancia de mantener parches forestales contiguos o una matriz de paisaje bosque-urbano-matorral para las poblaciones de zorro gris en Indiana y otros estados del Medio Oeste. Dada la predominancia de tierras privadas en la regi & oacute;n, la colaboraci & oacute;n entre gestores y propietarios resulta fundamental para tomar decisiones informadas sobre el manejo del h & aacute;bitat del zorro gris.

Abstract Several indices and studies have indicated declining populations of gray foxes ( Urocyon cinereoargenteus ) in several Midwest states in the United States. Causes of these declines are unknown and may vary by region but could be linked to habitat loss and fragmentation, changing mesocarnivore communities, disease, and other complex factors. During 2020–2023, we collected data (e.g., location, biological samples, reproductive tracts [females only]) from 26 global positioning system (GPS)‐collared gray foxes in central and southern Indiana, and data (e.g., biological samples) from 74 gray fox carcasses statewide. We estimated seasonal space use, cover selection, and resource selection of radiomarked gray foxes based on reproductive (Jan–Jun) and nonreproductive (Jul–Dec) seasons. To assess space use, we used a biased random bridge approach to estimate 95% utilization distributions (UDs), 30% intensity distributions (IDs; an index of the intensity of resource exploitation of areas), and 30% recursive distributions (RDs; rate at which resources are exploited) based on reproductive ( n = 21 foxes) and nonreproductive ( n = 23) seasons. Patterns of seasonal space use consistently included larger areas during the reproductive season (UD = 871.2 ha vs. 822.2 ha), although 95% confidence limits (CLs) overlapped. We used a use‐availability approach to assess second‐ (landscape scale) and third‐order (home‐range scale) cover selection. Calculations of selection ratios (proportional use/proportional availability) by season suggested weak patterns for landscape‐level selection, including no selection for any individual cover type and selection against agriculture‐row crop and open water, regardless of season. Patterns were somewhat stronger for home‐range‐level selection; frequency of visitation and relative time of residence were both positively associated with several cover types (e.g., upland shrubland or forest, developed‐low intensity, developed‐roads) and negatively associated with agriculture‐row crop. To assess resource selection, we used infinitely weighted logistic regression, constructed models using anthropogenic (e.g., distance to nearest developed cover type and building, density of buildings, traffic volume) and environmental (e.g., cover type, landscape connectivity, weather) covariates, and used Bayesian Information Criterion (BIC) to assess model performance. Probability of use was greatest in areas near agricultural cover (strongest relative effect), buildings, and roads, regardless of season, and probabilities substantially decreased >100 m from each, suggesting the potential importance of habitat edge to meet life requisites associated with cover and forage. For assessments of genetics, we extracted DNA from 102 individuals and genotyped each at approximately 1,700 single nucleotide polymorphisms (SNPs) using 2bRADseq. We identified 10 pairs of first‐order relatives (parent‐offspring or full siblings), 7 of which had precise location data, with inter‐individual distances ranging from 0.4 km to 13.2 km (mean = 6.1 km), consistent with the known dispersal distances of gray foxes. We assessed population genetic structure using clustering (STRUCTURE) and principal components analysis (PCA). The STRUCTURE analyses indicated weak genetic structuring, with statistical support for the optimal number of genetic clusters ( K ) = 4; however, individuals largely clustered into 2 groups with substantial admixture, and PCA revealed considerable overlap, suggesting only subtle differentiation rather than clearly distinct populations. To evaluate potential landscape barriers to gene flow, we generated landscape‐resistance surfaces based on the 3 best‐performing species distribution models (forest, refugia, and foraging) constructed using a maximum entropy approach and presence‐only data from community‐based observations analyzed during a different component of our study. We analyzed the relationship between genetic distance and geographic or resistance distances using linear mixed‐effects models with a maximum likelihood population effects structure. Model comparisons indicated that geographic distance best explained variation in genetic distance, and no landscape‐resistance model outperformed isolation by distance. These results suggest minimal barriers to gene flow within Indiana, although our sample distribution was heavily skewed toward south‐central Indiana. We classified mortalities from 13 GPS‐marked foxes as disease (46%), vehicle collision (15%), legal harvest (8%), potential poisoning (e.g., rodenticide, oxalate nephrosis due to ethylene glycol; 15%), and unknown (15%). Based on proportional‐hazards models, survival did not differ by sex, and mean annual survival probability was 0.61 ( n = 26). We used motion‐sensing cameras to monitor natal dens ( n = 6) of radiomarked foxes to confirm presence of pups and date of den abandonment, after which we measured den‐site characteristics. Two dens were closely associated with human‐built structures, and 4 dens were underground burrows. Compared to random locations, gray foxes selected den sites with a greater amount of horizontal cover at heights 1–3 m aboveground. Lastly, our examination of placental scars in reproductive tracts of females resulted in estimated mean litter sizes of 2.00 for females 1 to <2 years old and 3.33 for females ≥2 years old. Our results provide evidence that gray foxes in Indiana are an edge species with relatively large home ranges, relatively low reproductive rates, and good genetic health with no identifiable genetic barriers to dispersal, but they are also subject to relatively high exposure to disease, specifically canine distemper virus. Risk associated with increased movements may be somewhat mitigated through use of habitat edges for cover (e.g., predator avoidance, escape cover), but large movements may also increase exposure to disease vectors (e.g., ticks). Management considerations may include providing small patches designed to serve as buffer zones to increase amount of edge for foraging, and potentially also for use as travel corridors, particularly in areas with extensive agriculture. It may be possible to create edge as an ecological homologue to roads but with a lower potential risk of mortality via vehicle collisions. Conversely, risk could increase if use of such areas increases interactions with certain other wildlife species (e.g., coyotes [ Canis latrans ], northern raccoons [ Procyon lotor ]) that may increase levels of interspecific killing or transmission of diseases.

Concerns about declining gray fox (Urocyon cinereoargenteus) populations in the Midwest, USA, prompted a petition to list the prairie gray fox subspecies (U. c. ocythous) under the U.S. Endangered Species Act. Although previous studies identified a deep phylogenetic break between eastern and western lineages of the gray fox at the Great Plains Suture Zone, population structure within the Midwest remains poorly understood, complicating subspecies classification. To address this, we genotyped 339 individuals from the eastern lineage of the gray fox using SNPs generated from 2bRAD genomic sequencing to assess genetic diversity and structure. Bayesian clustering and PCA supported three genetic clusters (K = 3), revealing a cryptic break within Missouri that subdivides the morphologically defined range of U. c. ocythous and a secondary break coinciding with the Mississippi River and the currently accepted subspecies boundary. However, low pairwise FST values and admixture indicate weak overall genetic differentiation with ongoing gene flow, whereas declining genetic diversity at northern latitudes is reflective of founder effects from post-glacial population expansion. Consistent with prior mtDNA results, nuclear SNP data suggest that U. c. ocythous and U. c. cinereoargenteus are unlikely to represent distinct evolutionary units. However, because 2bRAD detects primarily neutral variation, whole-genome sequencing will be needed to test for adaptive divergence that might persist despite gene flow. Our findings provide an important step toward a comprehensive understanding of population structure and refining subspecies boundaries within the eastern lineage of the gray fox.

Secondary contact zones between deeply divergent, yet interfertile, lineages provide windows into the speciation process. North American grey foxes (Urocyon cinereoargenteus) are divided into western and eastern lineages that diverged approximately 1 million years ago. These ancient lineages currently hybridize in a relatively narrow zone of contact in the southern Great Plains, a pattern more commonly observed in smaller‐bodied taxa, which suggests relatively recent contact after a long period of allopatry. Based on local ancestry inference with whole‐genome sequencing (n = 43), we identified two distinct Holocene pulses of admixture. The older pulse (500–3500 YBP) reflected unidirectional gene flow from east to west, whereas the more recent pulse (70–200 YBP) of admixture was bi‐directional. Augmented with genotyping‐by‐sequencing data from 216 additional foxes, demographic analyses indicated that the eastern lineage declined precipitously after divergence, remaining small throughout most of the late Pleistocene, and expanding only during the Holocene. Genetic diversity in the eastern lineage was highest in the southeast and lowest near the contact zone, consistent with a westward expansion. Concordantly, distribution modelling indicated that during their isolation, the most suitable habitat occurred far east of today's contact zone or west of the Great Plains. Thus, long‐term isolation was likely caused by the small, distant location of the eastern refugium, with recent contact reflecting a large increase in suitable habitat and corresponding demographic expansion from the eastern refugium. Ultimately, long‐term isolation in grey foxes may reflect their specialized bio‐climatic niche. This system presents an opportunity for future investigation of potential pre‐ and post‐zygotic isolating mechanisms.

Predictions obtained from wildlife population models may be prone to influences associated with the quality of the data available for parameterization. We assessed accuracy of furtaker-assigned sex of bobcats (Lynx rufus; n = 123) harvested during 2017-2018 across the western USA by comparing those data to genetically assigned sex, the latter of which we assumed was 100% accurate. We also compared the precision of individual age estimates obtained through cementum annuli analysis (CAA) of the canines and incisors of harvested bobcats (n = 151), where true age was unknown. Because cementum-line deposition may vary across populations and by sex, we hypothesized that environmental factors may affect precision of age estimates obtained via CAA. Sex of bobcats as reported by furtakers was accurate 82% of the time, and the direction of sex-assignment error was approximately equivalent. Canine teeth were more precise than incisors for estimating age, age estimates for male bobcats may be more precise than for females, and precision of age estimates may decrease with age. However, use of incisors corrected with known rates of error may be preferred in some instances, such as studies that require live capture and tooth extraction or where assignment to age class is sufficient. In addition, we found that sex, median age, and mean elevation may influence precision of age estimates, whereas mean precipitation and geographic location (latitude, longitude) were uninformative. Knowledge of different types of errors associated with sex identification and age estimation may be integrated into population modeling efforts based on management objectives.

The gray fox (Urocyon cinereoargenteus) lineage diverged from all other extant canids at their most basal node and is restricted to the Americas. Previous mitochondrial analysis from coastal populations identified deeply divergent (up to 1 Mya) eastern and western lineages that predate most intraspecific splits in carnivores. We conducted genotyping by sequencing and mitochondrial analysis on gray foxes sampled across North America to determine geographic concordance between nuclear and mitochondrial contact zones and divergence times. We also estimated the admixture within the contact zone between eastern and western gray foxes based on nuclear DNA. Both datasets confirmed that eastern and western lineages met in the southern Great Plains (i.e. Texas and Oklahoma), where they maintained high differentiation. Admixture was generally low, with the majority of admixed individuals carrying <10% ancestry from the other lineage. Divergence times confirmed a mid-Pleistocene split, similar to the mitochondrial estimates. Taken together, findings suggest gray fox lineages represent an ancient divergence event, far older than most intraspecific divergences in North American carnivores. Low admixture may reflect a relatively recent time since secondary contact (e.g. post-Pleistocene) or, alternatively, ecological or reproductive barriers between lineages. Though further research is needed to disentangle these factors, our genomic investigation suggests species-level divergence exists between eastern and western gray fox lineages.

We examined phylogeographic structure in gray fox ( Urocyon cinereoargenteus ) across the United States to identify the location of secondary contact zone(s) between eastern and western lineages and investigate the possibility of additional cryptic intraspecific divergences. We generated and analyzed complete mitochondrial genome sequence data from 75 samples and partial control region mitochondrial DNA sequences from 378 samples to investigate levels of genetic diversity and structure through population- and individual-based analyses including estimates of divergence (F ST and SAMOVA), median joining networks, and phylogenies. We used complete mitochondrial genomes to infer phylogenetic relationships and date divergence times of major lineages of Urocyon in the United States. Despite broad-scale sampling, we did not recover additional major lineages of Urocyon within the United States, but identified a deep east-west split (∼0.8 million years) with secondary contact at the Great Plains Suture Zone and confirmed the Channel Island fox ( Urocyon littoralis ) is nested within U. cinereoargenteus . Genetic diversity declined at northern latitudes in the eastern United States, a pattern concordant with post-glacial recolonization and range expansion. Beyond the east-west divergence, morphologically-based subspecies did not form monophyletic groups, though unique haplotypes were often geographically limited. Gray foxes in the United States displayed a deep, cryptic divergence suggesting taxonomic revision is needed. Secondary contact at a common phylogeographic break, the Great Plains Suture Zone, where environmental variables show a sharp cline, suggests ongoing evolutionary processes may reinforce this divergence. Follow-up study with nuclear markers should investigate whether hybridization is occurring along the suture zone and characterize contemporary population structure to help identify conservation units. Comparative work on other wide-ranging carnivores in the region should test whether similar evolutionary patterns and processes are occurring.

An understudied aspect of vertebrate ecoimmunology has been the relative contributions of environmental factors (E), genetic background (G) and their interaction (G × E) in shaping immune development and function. Environmental temperature is known to affect many aspects of immune function and alterations in temperature regimes have been implicated in emergent disease outbreaks, making it a critical environmental factor to study in the context of immune phenotype determinants of wild animals. We assessed the relative influences of environmental temperature, genetic background and their interaction on first-year development of innate and adaptive immune defences of captive-born garter snakes Thamnophis elegans using a reciprocal transplant laboratory experiment. We used a full-factorial design with snakes from two divergent life-history ecotypes, which are known to differ in immune function in their native habitats, raised under conditions mimicking the natural thermal regime-that is, warmer and cooler-of each habitat. Genetic background (ecotype) and thermal regime influenced innate and adaptive immune parameters of snakes, but in an immune-component specific manner. We found some evidence of G × E interactions but no indication of adaptive plasticity with respect to thermal environment. At the individual level, the effects of thermal environment on resource allocation decisions varied between the fast- and the slow-paced life-history ecotypes. Under warmer conditions, which increased food consumption of individuals in both ecotypes, the former invested mostly in growth, whereas the latter invested more evenly between growth and immune development. Overall, immune parameters were highly flexible, but results suggest that other environmental factors are likely more important than temperature per se in driving the ecotype differences in immunity previously documented in the snakes under field conditions. Our results also add to the understanding of investment in immune development and growth during early postnatal life under different thermal environments. Our finding of immune-component specific patterns strongly cautions against oversimplification of the highly complex immune system in ecoimmunological studies. In conjunction, these results deepen our understanding of the degree of immunological flexibility wild animals present, information that is ever more vital in the context of rapid global environmental change.

Immunosenescence is a well-known phenomenon in mammal systems, but its relevance in other long-lived vertebrates is less understood. Further, the influence of age and reproductive effort on immune function in long-lived species can be challenging to assess, as long-term data are scarce and it is often difficult to sample the oldest age classes. We used the painted turtle (Chrysemys picta) to test hypotheses of immunosenescence and a trade-off between reproductive output and immune function in a population of a long-lived vertebrate that has been monitored for over 30 years. These long-term data are utilized to employ a unique approach of aging turtles with mark-recapture data and population-specific growth modeling to obtain more accurate estimates of age. We analyzed natural antibodies, lysis ability, and bactericidal competence in 126 individuals from 1 to 33 years of age captured during May and June in 2011. Older turtles exhibited greater natural antibody levels than young individuals across sexes. Young females with large clutches exhibited greater lysis ability, while older females with large clutches had decreased lysis ability, suggesting a trade-off between reproductive output and immune function conditional upon age. However, bactericidal competence increased later in the nesting season for older females. Our study rejects the hypothesis of immunosenescence in a long-lived turtle, despite evidence of actuarial and reproductive senescence in this population. Additionally, we detected mixed evidence for a trade-off between reproduction and immune health.

ABSTRACTNatural recolonization of bobcat (Lynx rufus) populations in the midwestern United States presents challenges for managers with limited knowledge of the species’ population dynamics in a highly fragmented agricultural landscape. Dispersal is a component of population dynamics of a recolonizing population, which is likely influenced by landscape features. To better understand population expansion, we examined dispersal characteristics of juvenile (<2 yr) bobcats in recently recolonized south‐central Iowa, USA, from 2003–2009. We radio‐collared and tracked dispersal fates of 61 individuals (34 males, 27 females), with 29 (22 males, 7 females) dispersing by approximately 2 years of age and the rest remaining philopatric. Most (65%) juvenile males dispersed, whereas only 26% of females dispersed. Initiation of dispersal varied, but none occurred in July–August. Dispersal duration ranged from 4–240 days. Average age at dispersal was 16.9 ± 1.1 (SE) months. Dispersal was most prevalent in an east‐west direction and straight‐line distances ranged from 6.6–203.2 km ( = 57.9 km). On average, males dispersed 44 km farther than females. Land cover composition was similar in natal and post‐dispersal core ranges and consisted predominantly (70%) of forest and grassland. Lower abundance of forest and grassland in areas north of the study area may ultimately limit the ability of juvenile bobcats to successfully disperse and expand throughout the Corn Belt of Iowa. © 2019 The Wildlife Society.

Early-life experiences can have far-reaching consequences for phenotypes into adulthood. The effect of early-life experiences on fitness, particularly under adverse conditions, is mediated by resource allocation to particular life-history traits. Reptiles exhibit great variation in life histories (e.g. indeterminate growth), thus selective pressures often mitigate the effects of early-life stress, particularly on growth and maturation. We examined the effects of early-life food restriction on growth, adult body size, physiology and reproduction in the checkered garter snake. Animals were placed on one of two early-life diet treatments: normal diet (approximating ad libitum feeding) or low diet (restricted to 20% of body mass in food weekly). At 15 weeks of age, low-diet animals were switched to the normal-diet treatment. Individuals fed a restricted diet showed reduced growth rates, depressed immunocompetence and a heightened glucocorticoid response. Once food restriction was lifted, animals experiencing nutritional stress early in life (low diet) caught up with the normal-diet group by increasing their growth, and were able to recover from the negative effects of nutritional stress on immune function and physiology. Growth restriction and the subsequent allocation of resources into increasing growth rates, however, had a negative effect on fitness. Mating success was reduced in low-diet males, while low-diet females gave birth to smaller offspring. In addition, although not a direct goal of our study, we found a sex-specific effect of early-life nutritional stress on median age of survival. Our study demonstrates both immediate and long-term effects of nutritional stress on physiology and growth, reproduction. and trade-offs among them.

—Despite the intense challenges to wildlife presented by urbanization, many species continue to survive and even to thrive in these highly impacted landscapes. In the urban matrix of Denver, Colorado, USA, two snake species persist in restricted urban habitats near the limit of their geographic ranges: the Western Terrestrial Gartersnake (Thamnophis elegans) and the Plains Gartersnake (Thamnophis radix). We used nuclear microsatellite markers to assess the population genetic structure of three populations of both species living syntopically in this highly developed urban environment and one population of T. elegans in natural habitat. Our findings indicate strong population structure, limited migration between populations of each species, and evidence of inbreeding and a loss of genetic diversity, with these patterns more pronounced in T. radix. Additionally, we do not find evidence of increased hybridization between these species in such confined habitat patches. These results suggest that populations of long-lived vertebrate species may require intervention to escape long-term detrimental effects of habitat fragmentation and subsequent genetic isolation.

The insulin/insulin-like signaling pathway (IIS) has been shown to mediate life history trade-offs in mammalian model organisms, but the function of this pathway in wild and non-mammalian organisms is understudied. Populations of western terrestrial garter snakes (Thamnophis elegans) around Eagle Lake, California, have evolved variation in growth and maturation rates, mortality senescence rates, and annual reproductive output that partition into two ecotypes: "fast-living" and "slow-living". Thus, genes associated with the IIS network are good candidates for investigating the mechanisms underlying ecological divergence in this system. We reared neonates from each ecotype for 1.5years under two thermal treatments. We then used qPCR to compare mRNA expression levels in three tissue types (brain, liver, skeletal muscle) for four genes (igf1, igf2, igf1r, igf2r), and we used radioimmunoassay to measure plasma IGF-1 and IGF-2 protein levels. Our results show that, in contrast to most mammalian model systems, igf2 mRNA and protein levels exceed those of igf1 and suggest an important role for igf2 in postnatal growth in reptiles. Thermal rearing treatment and recent growth had greater impacts on IGF levels than genetic background (i.e., ecotype), and the two ecotypes responded similarly. This suggests that observed ecotypic differences in field measures of IGFs may more strongly reflect plastic responses in different environments than evolutionary divergence. Future analyses of additional components of the IIS pathway and sequence divergence between the ecotypes will further illuminate how environmental and genetic factors influence the endocrine system and its role in mediating life history trade-offs.

Despite a broad distribution, general habitat requirements, and a large dispersal potential, bobcats (Lynx rufus) exhibit a genetic division that longitudinally transects central North America. We investigated (1) whether the climate of the Last Glacial Maximum (LGM; 21kya) isolated bobcats into refugia and also whether the current climate influences gene flow between the segregate populations and (2) whether the geographical patterns in cranial morphology reflect population identity. We created ecological niche models (ENMs) to evaluate climatic suitability and to estimate distributions of the disparate populations under both historical (LGM) and contemporary conditions. We used two-dimensional geometric morphometric methods to evaluate variations in the cranium and mandible. These variations were then regressed across geographical variables to assess morphological differences throughout the range of the bobcat. ENMs projected onto LGM climate provided evidence of refugia during the LGM via increased suitability in the north-west and south-east portions of this species' range. Contemporarily, our models suggest that the Great Plains may be restricting bobcat migration and gene flow, effectively maintaining disparate populations. Morphological analyses identified a significant linear trend in shape variation across latitudinal and longitudinal gradients rather than distinct morphological divergence between lineages. Similar shape variations, however, did converge in approximate locations of assumed refugia. The findings of the present study provide a robust assessment of the biogeographical considerations for the population genetic structure of bobcats.

Climate change may subject animals to increasingly stressful environmental conditions, which could have negative physiological consequences if stress levels are elevated for long periods. We conducted a manipulative experiment to determine the effects of a novel climate on stress levels and immune function in a model reptile species, the painted turtle. We collected turtles from four populations across the species' geographic range and housed them in a common-garden in one population's local climate. We measured levels of the stress hormone corticosterone and tested two aspects of innate immune function, bactericidal capacity and natural antibody agglutination, at the time of capture (baseline) and three additional time points over 1 year. The four populations did not differ in corticosterone levels over the course of 1 year, and corticosterone levels were also similar at each sampling period except that post-hibernation corticosterone levels were significantly lower than the previous three time points. Furthermore, we found no evidence that elevated corticosterone depressed immune function in the painted turtle. Our study suggests that turtles exposed to novel climatic conditions did not display a detectable stress response, nor did the novel climate depress immune function in the transplanted populations. Therefore, in terms of innate immune function, turtles may be relatively resilient to at least small changes in climatic conditions.

Significance Comparative analyses of central molecular networks uncover variation that can be targeted by biomedical research to develop insights and interventions into disease. The insulin/insulin-like signaling and target of rapamycin (IIS/TOR) molecular network regulates metabolism, growth, and aging. With the development of new molecular resources for reptiles, we show that genes in IIS/TOR are rapidly evolving within amniotes (mammals and reptiles, including birds). Additionally, we find evidence of natural selection that diversified the hormone-receptor binding relationships that initiate IIS/TOR signaling. Our results uncover substantial variation in the IIS/TOR network within and among amniotes and provide a critical step to unlocking information on vertebrate patterns of genetic regulation of metabolism, modes of reproduction, and rates of aging.

The insulin/insulin-like signaling and target of rapamycin (IIS/TOR) network regulates lifespan and reproduction, as well as metabolic diseases, cancer, and aging. Despite its vital role in health, comparative analyses of IIS/TOR have been limited to invertebrates and mammals. We conducted an extensive evolutionary analysis of the IIS/TOR network across 66 amniotes with 18 newly generated transcriptomes from nonavian reptiles and additional available genomes/transcriptomes. We uncovered rapid and extensive molecular evolution between reptiles (including birds) and mammals: (i) the IIS/TOR network, including the critical nodes insulin receptor substrate (IRS) and phosphatidylinositol 3-kinase (PI3K), exhibit divergent evolutionary rates between reptiles and mammals; (ii) compared with a proxy for the rest of the genome, genes of the IIS/TOR extracellular network exhibit exceptionally fast evolutionary rates; and (iii) signatures of positive selection and coevolution of the extracellular network suggest reptile- and mammal-specific interactions between members of the network. In reptiles, positively selected sites cluster on the binding surfaces of insulin-like growth factor 1 (IGF1), IGF1 receptor (IGF1R), and insulin receptor (INSR); whereas in mammals, positively selected sites clustered on the IGF2 binding surface, suggesting that these hormone-receptor binding affinities are targets of positive selection. Further, contrary to reports that IGF2R binds IGF2 only in marsupial and placental mammals, we found positively selected sites clustered on the hormone binding surface of reptile IGF2R that suggest that IGF2R binds to IGF hormones in diverse taxa and may have evolved in reptiles. These data suggest that key IIS/TOR paralogs have sub- or neofunctionalized between mammals and reptiles and that this network may underlie fundamental life history and physiological differences between these amniote sister clades.

Highly mobile species that thrive in a wide range of habitats are expected to show little genetic differentiation across their range. A limited but growing number of studies have revealed that patterns of broad-scale genetic differentiation can and do emerge in vagile, continuously distributed species. However, these patterns are complex and often shaped by both historical and ecological factors. Comprehensive surveys of genetic variation at a broad scale and at high resolution are useful for detecting cryptic spatial genetic structure and for investigating the relative roles of historical and ecological processes in structuring widespread, highly mobile species. In this study, we analysed 10 microsatellite loci from over 1900 samples collected across the full range of mule deer (Odocoileus hemionus), one of the most widely distributed and abundant of all large mammal species in North America. Through both individual- and population-based analyses, we found evidence for three main genetic lineages, one corresponding to the mule deer' morphological type and two to the black-tailed deer' type. Historical biogeographic events likely are the primary drivers of genetic divergence in this species; boundaries of the three lineages correspond well with predictions based on Pleistocene glacial cycles, and substructure within each lineage demonstrates island vicariance. However, across large geographic areas, including the entire mule deer lineage, we found that genetic variation fit an isolation-by-distance pattern rather than discrete clusters. A lack of genetic structure across wide geographic areas of the continental west indicates that ecological processes have not resulted in restrictions to gene flow sufficient for spatial genetic structure to emerge. Our results have important implications for our understanding of evolutionary mechanisms of divergence, as well as for taxonomy, conservation and management.

ABSTRACT Sex and age data are fundamental vital statistics used to characterize wildlife populations, often integral to models used to assess population responses to harvest or make other management decisions. Misidentification errors could ultimately result in poor management decisions by misrepresenting harvest or population structure. We compared field examination and genetic identification of sex of bobcats (Lynx rufus; n = 248) collected during the 2009–2010 harvest season in Oregon, USA. Furtaker‐reported sex assignment and genetics analysis mismatched for 51 (20.6%) cases. In 31 (12.5%) cases, bobcats reported as females were classified as males by genetic analysis, and vice versa for the remaining 20 individuals. Quantification of errors in sex assignment allows for acknowledgment of technique and data limitations and may allow for adjustments to be considered during decision‐making processes. State agencies may consider providing formal training in field identification techniques and subsampling harvested bobcats for genetic sex assignment in an effort to more accurately reflect sex ratios in the harvest. © 2014 The Wildlife Society.