Search

Abstract Wolverine distribution contracted along the southern periphery of its range in North America during the 19th and 20th centuries due primarily to human influences. This history, along with low densities, sensitivity to climate change, and concerns about connectivity among fragmented habitats spurred the recent US federal listing of threatened status and special concern status in Canada. To help inform large scale landscape connectivity, we collected 882 genetic samples genotyped at 19 microsatellite loci. We employed multiple statistical models to assess the landscape factors (terrain complexity, human disturbance, forest configuration, and climate) associated with wolverine genetic connectivity across 2.2 million km2 of southwestern Canada and the northwestern contiguous United States. Genetic similarity (positive spatial autocorrelation) of wolverines was detected up to 555 km and a high-to-low gradient of genetic diversity occurred from north-to-south. Landscape genetics analyses confirmed that wolverine genetic connectivity has been negatively influenced by human disturbance at broad scales and positively influenced by forest cover and snow persistence at fine- and broad–scales, respectively. This information applied across large landscapes can be used to guide management actions with the goal of maintaining or restoring population connectivity.

Abstract Genetic rescue—an increase in population fitness following the introduction of new alleles—has been proven to ameliorate inbreeding depression in small, isolated populations, yet is rarely applied as a conservation tool. A lingering question regarding genetic rescue in wildlife conservation is how long beneficial effects persist in admixed populations. Using data collected over 40 years from 1192 endangered Florida panthers (Puma concolor coryi) across nine generations, we show that the experimental genetic rescue implemented in 1995—via the release of eight female pumas from Texas—alleviated morphological, genetic, and demographic correlates of inbreeding depression, subsequently preventing extirpation of the population. We present unequivocal evidence, for the first time in any terrestrial vertebrate, that genetic and phenotypic benefits of genetic rescue remain in this population after five generations of admixture, which helped increase panther abundance (> fivefold) and genetic effective population size (> 20-fold). Additionally, even with extensive admixture, microsatellite allele frequencies in the population continue to support the distinctness of Florida panthers from other North American puma populations, including Texas. Although threats including habitat loss, human-wildlife conflict, and infectious diseases are challenges to many imperiled populations, our results suggest genetic rescue can serve as an effective, multi-generational tool for conservation of small, isolated populations facing extinction from inbreeding.

Abstract Background Studies of animal habitat selection are important to identify and preserve the resources species depend on, yet often little attention is paid to how habitat needs vary depending on behavioral state. Fishers (Pekania pennanti) are known to be dependent on large, mature trees for resting and denning, but less is known about their habitat use when foraging or moving within a home range. Methods We used GPS locations collected during the energetically costly pre-denning season from 12 female fishers to determine fisher habitat selection during two critical behavioral activities: foraging (moving) or resting, with a focus on response to forest structure related to past forest management actions since this is a primary driver of fisher habitat configuration. We characterized behavior based on high-resolution GPS and collar accelerometer data and modeled fisher selection for these two behaviors within a home range (third-order selection). Additionally, we investigated whether fisher use of elements of forest structure or other important environmental characteristics changed as their availability changed, i.e., a functional response, for each behavior type. Results We found that fishers exhibited specialist selection when resting and generalist selection when moving, with resting habitat characterized by riparian drainages with dense canopy cover and moving habitat primarily influenced by the presence of mesic montane mixed conifer forest. Fishers were more tolerant of forest openings and other early succession elements when moving than resting. Conclusions Our results emphasize the importance of considering the differing habitat needs of animals based on their movement behavior when performing habitat selection analyses. We found that resting fishers are more specialist in their habitat needs, while foraging fishers are more generalist and will tolerate greater forest heterogeneity from past disturbance.

Natural resource agencies are frequently tasked with monitoring populations of at-risk species to ensure management activities do not negatively affect the viability of wildlife populations. Typically, these monitoring efforts evaluate trends in a population’s abundance, occupancy, or geographic distribution. Often, surveys provide local information, but results are generally not incorporated into broad-scale monitoring efforts that focus on range-wide population changes due to their variable nature in both spatial extent and effort. We investigated whether aggregating these local (hereafter “variable”) surveys can generate enough statistical power to estimate broad-scale population trends using simulations of declining populations of fishers (Pekania pennati) over a 10-year time horizon. Our simulations included three population sizes which we refer to as abundant, common, and rare (N0 = 700, 350, and 100 individuals, respectively) with each declining at a rapid and moderate pace (λ = 0.933, and 0.977, respectively). For each population, we simulated variable surveys using an occupancy framework to subsample the population with parameters that mimic combining multiple independent monitoring efforts which vary annually in location, and effort. Regardless of spatial consistency of annual sampling, there was minimal variation in statistical power under both high and low detection probability simulations. However, when sampling effort varied each year, statistical power was lower for most populations and sampling scenarios when compared to consistent sampling effort unless some baseline level of sampling effort was reliably achieved in all years. In many cases, adding low-level consistent baseline sampling to variable surveys resulted in statistical power close to that of consistent sampling efforts. Our results suggest statistical power is driven by annual consistency in the proportion of landscape sampled rather than spatial consistency in sampling locations. This result indicates that current variable surveys could be leveraged and combined to detect population declines for at-risk species at broad-scales if a baseline proportion of landscape is robustly sampled. The level of baseline sampling is highly dependent on population size and magnitudes of population change. In simulations with a common or abundant population experiencing a rapid decline, a baseline survey effort of at least 5% of the landscape in combination with variable surveys resulted in statistical power consistently above the standard threshold of 0.80 for occupancy monitoring. Leveraging existing local efforts to achieve high detection probability and baseline sampling would reduce financial and logistical burdens of broad-scale wildlife monitoring efforts.

Abstract Species' ranges are shifting rapidly with climate change, altering the composition of biological communities and interactions within and among species. Hybridization is among the species interactions that may change markedly with climate change, yet it is understudied relative to others. We used non‐invasive genetic detections to build a maximum entropy species distribution model and investigate the factors that delimit the present and future ranges of American marten (Martes americana) and Pacific marten (Martes caurina) in a contact zone in the Northern Rockies. We found that climate change will decrease the suitable habitat predicted for both species, as well as the amount of overlap in predicted suitable habitat between the species. Interestingly, predicted suitable habitat for Pacific marten extended further north in the study region than our genetic detections for the species, suggesting that biotic factors, such as interactions with American marten, may affect the realized range of this species. Our results suggest that future work investigating the interactions among biotic and abiotic factors that influence hybrid zone dynamics is important for predicting the futures of these two species in this area under climate change.

Physical and genetic isolation are recognized as significant threats to wildlife, especially in large carnivores inhabiting fragmented landscapes. We conducted an initial genetic assessment of pumas (Puma concolor) using 19 microsatellite loci for the emblematic puma population in the Torres del Paine UNESCO Biosphere Reserve in southernmost Chile, which exhibits some distinctive phenology that some local people speculate may be due to isolation and inbreeding depression. We extracted DNA from 385 scats collected in the field, of which 96 were identified as puma, representing 20 unique individuals. Torres del Paine pumas exhibited an Ho (0.51) only slightly lower than He (0.53), with 2 of the 19 loci significantly out of Hardy–Weinberg Equilibrium. Tests for a recent bottleneck of the population were not significant. The small sample size of individuals notwithstanding, these results seemingly do not support high levels of inbreeding. We also identified individual pumas in the field and assessed them for observable cowlicks (twirls of fur on their backs), a trait some have associated with genetic inbreeding depression in other puma populations. A total of 7 of 39 pumas exhibited cowlicks, consistent with geographic patterns of cowlicks within the species. Our tests exploring population structure among local pumas provided the most support for a single-population cluster, but we explored secondary structures as well, given its conservation implications. We encourage additional sampling in the region to further explore population structure and connectivity and determine the conservation status of the region’s pumas to guide the development of best strategies to ensure their persistence.

Abstract The need for widespread occurrence data to inform species conservation has prompted interest in large, national‐scale environmental DNA (eDNA) monitoring strategies. However, targeted eDNA assays are seldom validated for use across broad geographic areas. Here, we validated 46 new and previously published probe‐based qPCR assays targeting invasive species throughout the continental United States. We drew upon current taxonomies, range maps, publicly available sequences, and tissue archives to evaluate all potentially sympatric confamilial species and genetically similar extrafamilial taxa. Out of 5276 unique assay‐nontarget taxon combinations, we were able to test 4206 (80%). We characterized levels of validation and specificity for each of eight federal geographic regions and provided an online tool with state‐level information, as well as detailed assay descriptions in an appendix. Specificity testing benefited from extensive use of eDNAssay—a machine learning classifier trained to predict qPCR cross‐amplification—which we found to be 96% accurate in 649 unique tests that underwent paired in silico and in vitro testing. Predictions of assay specificity (the true negative rate) were 98–100% accurate, depending on the classification threshold used. This work provides both an immediate resource for invasive species surveillance and demonstrates an enhanced in silico, geographically subdivided validation framework to aid in future large‐scale validation efforts.

Abstract Environmental DNA (eDNA) sampling is a powerful tool for rapidly characterizing biodiversity patterns for specious, cryptic taxa with incomplete taxonomies. One such group that are also of high conservation concern are North American freshwater gastropods. In particular, springsnails of the genus Pyrgulopsis (Family: Hydrobiidae) are prevalent throughout the western United States where >140 species have been described. Many of the described species are narrow endemics known from a single spring or locality, and it is believed that there are likely many additional species which have yet to be described. The distribution of these species across the landscape is of interest because habitat loss and degradation, climate change, groundwater mining, and pollution have resulted in springsnail imperilment rates as high as 92%. Determining distributions with conventional sampling methods is limited by the fact that these snails are often

Abstract Wildlife conservation necessitates understanding spatiotemporal drivers that facilitate disease outbreaks. Wildlife diseases are influenced by population and landscape level factors which affects host species’ persistence through time. Recurrent pneumonia outbreaks in bighorn sheep have impeded population recovery throughout the western US. Recovery efforts have included translocating animals, limiting contact with known reservoirs, removing infected individuals, and depopulating herds, but pneumonia outbreaks continue to negatively impact recovery. Here, our objective was to systematically review the current literature focused on population and landscape level drivers that can contribute to pneumonia outbreaks in bighorn sheep. We reviewed 115 studies and discovered consistent themes important to address for future conservation. One of the primary themes to advance management includes understanding how population demographics, such as age and sex cohorts, can help elucidate drivers and maintenance of pathogens associated with respiratory disease. Second, broadening knowledge of landscape level processes including population connectivity and metapopulation dynamics can inform management and recovery efforts. We identified a need for comprehensive assessments that incorporate population dynamics, landscape genomics, and population connectivity across multiple spatiotemporal scales to advance landscape management. Finally, we provide directions for future research to help managers mitigate pneumonia outbreaks and aid bighorn sheep recovery.

Conserving genetic connectivity is fundamental to species persistence, yet rarely is made actionable into spatial planning for imperilled species. Climate change and habitat degradation have added urgency to embrace connectivity into networks of protected areas. Our two-step process integrates a network model with a functional connectivity model, to identify population centres important to maintaining genetic connectivity then to delineate those pathways most likely to facilitate connectivity thereamong for the greater sage-grouse (Centrocercus urophasianus), a species of conservation concern ranging across eleven western US states and into two Canadian provinces. This replicable process yielded spatial action maps, able to be prioritized by importance to maintaining range-wide genetic connectivity. We used these maps to investigate the efficacy of 3.2 million ha designated as priority areas for conservation (PACs) to encompass functional connectivity. We discovered that PACs encompassed 41.1% of cumulative functional connectivity—twice the amount of connectivity as random—and disproportionately encompassed the highest-connectivity landscapes. Comparing spatial action maps to impedances to connectivity such as cultivation and woodland expansion allows both planning for future management and tracking outcomes from past efforts.

Abstract Resource managers have rarely accounted for evolutionary dynamics in the design or implementation of climate change adaptation strategies. We brought the research and management communities together to identify challenges and opportunities for applying evidence from evolutionary science to support on‐the‐ground actions intended to enhance species' evolutionary potential. We amalgamated input from natural‐resource practitioners and interdisciplinary scientists to identify information needs, current knowledge that can fill those needs, and future avenues for research. Three focal areas that can guide engagement include: (1) recognizing when to act, (2) understanding the feasibility of assessing evolutionary potential, and (3) identifying best management practices. Although researchers commonly propose using molecular methods to estimate genetic diversity and gene flow as key indicators of evolutionary potential, we offer guidance on several additional attributes (and their proxies) that may also guide decision‐making, particularly in the absence of genetic data. Finally, we outline existing decision‐making frameworks that can help managers compare alternative strategies for supporting evolutionary potential, with the goal of increasing the effective use of evolutionary information, particularly for species of conservation concern. We caution, however, that arguing over nuance can generate confusion; instead, dedicating increased focus on a decision‐relevant evidence base may better lend itself to climate adaptation actions.

Abstract Being able to associate an organism with a scientific name is fundamental to our understanding of its conservation status, ecology, and evolutionary history. Gastropods in the subfamily Physinae have been especially troublesome to identify because morphological variation can be unrelated to interspecific differences and there have been widespread introductions of an unknown number of species, which has led to a speculative taxonomy. To resolve uncertainty about species diversity in North America, we targeted an array of single-locus species delimitation methods at publically available specimens and new specimens collected from the Snake River basin, USA to generate species hypotheses, corroborated using nuclear analyses of the newly collected specimens. A total-evidence approach delineated 18 candidate species, revealing cryptic diversity within recognized taxa and a lack of support for other named taxa. Hypotheses regarding certain local endemics were confirmed, as were widespread introductions, including of an undescribed taxon likely belonging to a separate genus in southeastern Idaho for which the closest relatives are in southeast Asia. Overall, single-locus species delimitation was an effective first step toward understanding the diversity and distribution of species in Physinae and to guiding future investigation sampling and analyses of species hypotheses.

Abstract Environmental DNA (eDNA) metabarcoding, where specific DNA markers (barcodes) are purified from the environment, sequenced, and used to identify organisms, is revolutionizing biodiversity science. Researchers, industry, and governments are increasingly incorporating eDNA surveys into their toolkits for biomonitoring because of their high accuracy, taxonomically holistic lens, and ease of deployment. Yet, the full value of this rich and revolutionary technique is not being realized because eDNA data are rarely maintained in consistent formats or on open platforms that facilitate easy re‐use or integration with other data layers. Here, we discuss opportunities to improve the accessibility and “FAIRness” of eDNA records with the aim to maximize the value of this remarkable source of information on environmental state and change.

Abstract Environmental DNA (eDNA) concentration exhibits a positive correlation with organism abundance in nature, but modeling this relationship could be substantially improved by incorporating the biology of eDNA production. A recent model (Molecular Ecology, 10.1111/mec.15543) extended models of physiological allometric scaling to eDNA production, hypothesizing that brook trout eDNA production scales nonlinearly with mass as a power function with scaling coefficients

Abstract A lineage of the Mountain Sucker species complex (Pantosteus jordani) exists as a genetically and morphologically distinct taxon restricted to the Missouri River basin. This species is thought to be declining throughout its range and is assumed to be extirpated from the southern portion of its distribution. We developed a quantitative PCR‐based environmental DNA assay for P. jordani to help define and monitor its current range. The assay is both specific to P. jordani and sensitive to low amounts of DNA, with a detection limit of 10 DNA copies per reaction. In vitro experiments involved testing DNA from twenty tissue samples, collected from the Missouri River basin in Montana and Wyoming. The assay efficiently detected DNA of all P. jordani samples and did not amplify DNA of any closely related nontarget species. Additionally, 29 environmental DNA samples were taken in 19 waterbodies within P. jordani range and its presence or absence was determined prior to sampling at six of 29 sites. All sites where P. jordani was known absent produced negative results, and all sites where it was known present were confirmed with environmental DNA detections. The new assay was able to detect P. jordani at ten sites which were not previously known to contain individuals, demonstrating that this tool has the potential to rapidly expand the current understanding of this taxon's distribution.

Abstract Background We evaluated whether occupancy modeling, an approach developed for detecting rare wildlife species, could overcome inherent accuracy limitations associated with rapid disease tests to generate fast, accurate, and affordable SARS-CoV-2 prevalence estimates. Occupancy modeling uses repeated sampling to estimate probability of false negative results, like those linked to rapid tests, for generating unbiased prevalence estimates. Methods We developed a simulation study to estimate SARS-CoV-2 prevalence using rapid, low-sensitivity, low-cost tests and slower, high-sensitivity, higher cost tests across a range of disease prevalence and sampling strategies. Results Occupancy modeling overcame the low sensitivity of rapid tests to generate prevalence estimates comparable to more accurate, slower tests. Moreover, minimal repeated sampling was required to offset low test sensitivity at low disease prevalence (0.1%), when rapid testing is most critical for informing disease management. Conclusions Occupancy modeling enables the use of rapid tests to provide accurate, affordable, real-time estimates of the prevalence of emerging infectious diseases like SARS-CoV-2.

Abstract When analyzing environmental samples for DNA from multiple taxa, researchers must usually decide between iterative analyses with single‐taxon assays—which are reliable and sensitive, but also laborious to apply—and approaches such as metabarcoding that can simultaneously target multiple species, but which are less sensitive for detection across taxa. Here, we test an intermediate approach that allows efficient, parallel assessment of taxon‐specific qPCR assays via high‐throughput quantitative PCR (HT‐qPCR). Based on an assessment of over 500 environmental samples, we found that sensitivity and specificity of our HT‐qPCR approach were similar (concordance 0.900–1.000) to values achieved through single‐species qPCR in six out of seven assays tested. Thus, HT‐qPCR may provide analyses of similar quality as single‐species qPCR analyses for environmental DNA, but at a lower cost per taxon. We see this approach as being a valuable addition to the eDNA sampling toolbox, particularly for situations where reliable inferences are needed for a defined suite of rare invasive or imperiled taxa.

Abstract Effects of historical fire suppression in forested ecosystems, combined with increasingly frequent and prolonged periods of drought due to a changing climate, are predicted to drive increases in the extent and intensity of wildfires in western North America and elsewhere. Understanding the effects of wildfires on forest‐dependent species and interactions among species is important for conservation and management decisions. We used data collected from a long‐term carnivore monitoring program in northern California and southern Oregon, USA to investigate the effects of three mixed‐severity wildfires and salvage logging on a population of fishers (Pekania pennanti), forest‐dependent carnivoran of conservation concern, and a co‐occurring population of gray foxes (Urocyon cinereoargenteus), a competitor of similar body size. We developed a spatial capture‐recapture population model to estimate the short‐term effects of the wildfires and salvage logging on fisher and gray fox abundances, distributions, apparent survival and recruitment, and species interactions using non‐invasive genetic data collected three years prior to and three years following wildfires. Fisher abundance decreased significantly in areas of low‐, medium‐, and high‐severity wildfire. Gray fox abundance decreased in the years before the wildfires, but rebounded in subsequent years. Medium‐severity wildfire had a negative effect on gray fox density, but high‐severity wildfire and fisher density had positive effects on gray fox density. Salvage logging had negative effects on both fisher and gray fox density. Our results suggest that increased severity, extent, and frequency of wildfires in the western USA will affect fisher populations negatively and alter the composition of mesocarnivoran communities.

Abstract Molecular tools are commonly directed at refining taxonomies and the species that constitute their fundamental units. This has been especially insightful for groups for which species hypotheses are ambiguous and have largely been based on morphological differences between certain life stages or sexes, and has added importance when taxa are a focus of conservation efforts. Here, we examine the taxonomic status of Arsapnia arapahoe, a winter stonefly in the family Capniidae that is a species of conservation concern because of its limited abundance and restricted range in northern Colorado, USA. Phylogenetic analyses of sequences of mitochondrial and nuclear genes of this and other capniid stoneflies from this region and elsewhere in western North America indicated extensive haplotype sharing, limited genetic differences, and a lack of reciprocal monophyly between A. arapahoe and the sympatric A. decepta, despite distinctive and consistent morphological differences in the sexual apparatus of males of both species. Analyses of autosomal and sex‐linked single nucleotide polymorphisms detected using genotyping by sequencing indicated that all individuals of A. arapahoe consisted of F1 hybrids between female A. decepta and males of another sympatric stonefly, Capnia gracilaria. Rather than constitute a self‐sustaining evolutionary lineage, A. arapahoe appears to represent the product of nonintrogressive hybridization in the limited area of syntopy between two widely distributed taxa. This offers a cautionary tale for taxonomists and conservation biologists working on the less‐studied components of the global fauna.

Jaguar (Panthera onca) are of conservation concern and occur at very low densities in the northern portion of their range in northern Mexico and the southwestern United States. Environmental DNA sampling to detect genetic material from drinking water may be an effective approach for jaguar detection in these arid landscapes. Here we develop a qPCR assay for the detection of jaguar mitochondrial DNA, show that large quantities of DNA (mean 66,820 copies/L) can be found in the drinking water of captive animals, and observe detectable levels of DNA (80 copies/L) in a wild habitat with known jaguar populations. We suggest that environmental DNA sampling may represent a useful, complementary sampling tool for detection of rare jaguars, although effective application would require careful consideration of DNA persistence time in the environment.

Wildlife dispersal directly influences population expansion patterns, and may have indirect effects on the spread of wildlife diseases. Despite its importance to conservation, little is known about dispersal for several species. Dispersal processes in expanding wolf (Canis lupus) populations in Europe is not well documented. Documenting the natural dispersal pattern of the expanding wolf population in the Alps might help understanding the overall population dynamics and identifying diseases that might be connected with the process. We documented 55 natural dispersal events of the expanding Italian wolf alpine population over a 20-year period through the use of non-invasive genetic sampling. We examined a 16-locus microsatellite DNA dataset of 2857 wolf samples mainly collected in the Western Alps. From this, we identified 915 individuals, recaptured 387 (42.3%) of individuals, documenting 55 dispersal events. On average, the minimum straight dispersal distance was 65.8 km (±67.7 km), from 7.7 km to 517.2 km. We discussed the potential implications for maintaining genetic diversity of the population and for wildlife diseases spreading.

Canine distemper virus (CDV) is a multi-host pathogen with variable clinical outcomes of infection across and within species. We used whole-genome sequencing (WGS) to search for viral markers correlated with clinical distemper in African lions. To identify candidate markers, we first documented single-nucleotide polymorphisms (SNPs) differentiating CDV strains associated with different clinical outcomes in lions in East Africa. We then conducted evolutionary analyses on WGS from all global CDV lineages to identify loci subject to selection. SNPs that both differentiated East African strains and were under selection were mapped to a phylogenetic tree representing global CDV diversity to assess if candidate markers correlated with documented outbreaks of clinical distemper in lions (n = 3). Of 54 SNPs differentiating East African strains, ten were under positive or episodic diversifying selection and 20 occurred in the clinical strain despite strong purifying selection at those loci. Candidate markers were in functional domains of the RNP complex (n = 19), the matrix protein (n = 4), on CDV glycoproteins (n = 5), and on the V protein (n = 1). We found mutations at two loci in common between sequences from three CDV outbreaks of clinical distemper in African lions; one in the signaling lymphocytic activation molecule receptor (SLAM)-binding region of the hemagglutinin protein and another in the catalytic center of phosphodiester bond formation on the large polymerase protein. These results suggest convergent evolution at these sites may have a functional role in clinical distemper outbreaks in African lions and uncover potential novel barriers to pathogenicity in this species.

Western toads (species complex comprised of Anaxyrus boreas, A. canorus, A. exsul, and A. nelsoni) are widely distributed in the western United States but are declining, particularly in the southeastern extent of their range. The subspecies A. b. boreas is listed as a Species of Greatest Conservation Need in New Mexico, Colorado, Utah, and Wyoming. Reliable and sensitive methods for delineating distributions of western toads are critical for monitoring the status of the species and prioritizing conservation efforts. We developed two qPCR assays for detecting western toad DNA in environmental DNA samples. Both markers efficiently and reliably detect low concentrations of western toad DNA across their range in the conterminous U. S. without detecting non-target, sympatric species. To determine the optimal annual sampling period, we then tested these markers using repeated sampling in ponds where western toads were known to be present. Quantities of collected eDNA varied widely across samples, but sample-level detections across sites exceeded 80% for June sampling. In the later summer, detection dropped off sharply with only a single detection in the ten samples collected throughout August. Keywords: eDNA, qPCR, Freshwater, Monitoring, Wetland, Amphibian

Abstract Genetic connectivity results from the dispersal and reproduction of individuals across landscapes. Mammalian populations frequently exhibit sex‐biased dispersal, but this factor has rarely been addressed in individual‐based landscape genetics research. In this study, we evaluate the effects of sex‐biased dispersal and landscape heterogeneity on genetic connectivity in a small and isolated population of fisher (Pekania pennanti). We genotyped 247 fisher samples collected across the southern Sierra Nevada Mountains of California. We tested for genetic evidence of sex‐biased dispersal using sex‐specific population structure and spatial autocorrelation analyses, and sex‐biased dispersal tests of the assignment index, FST, and FIS. We developed resistance surfaces for eight landscape features hypothesized to affect gene flow and optimized each resistance surface independently by sex. Using multiple regression of distance matrices and an information‐theoretic model selection approach, we fit models of genetic distance to landscape resistance distance separately by sex and geographic region. We found genetic evidence of sex‐biased dispersal with significant differences in FST, FIS, and spatial autocorrelation between sexes. Optimal resistance values differed by sex, and model variables, fit, and parameter estimates varied substantially both between sexes and between geographic regions. We found a stronger relationship between landscape features and genetic distance for females, the philopatric sex, than the more widely dispersing males. Our results show that landscape features influencing gene flow differed by both sex and regional heterogeneity. Conducting analyses by sex and by region allowed for the identification of landscape genetics relationships not discernible when analyzed together. Our results show that failing to account for these factors can confound results and obscure relationships between landscape features and gene flow.