Genetic structuring in wildlife populations is driven by barriers that restrict gene flow as well as the history of population demography. Mechanisms driving genetic structuring can be nuanced in group-living species, such as gray wolves (Canis lupus). Behavioral factors, such as social affiliation and resistance, natal habitat imprinting, and trade-offs between dispersal from natal packs and territorial biding, affect habitat selection of wolves despite landscape barriers providing little resistance to their extensive dispersal capabilities. Wolves were previously extirpated from Idaho, USA, and current populations are the result of both reintroductions in 1995 and 1996 and natural dispersal from Canada. In this context we examined genetic structure of wolves in Idaho using 101 individuals genotyped at 18 nuclear DNA microsatellite loci and a subset of 38 individuals genotyped at 1019 single nucleotide polymorphism markers. We hypothesized panmictic (i.e., random mating) genetic structure in Idaho due to the long-distance dispersal abilities of gray wolves. Contrary to our hypothesis, we found three genetic clusters of gray wolves in Idaho, primarily supported by SNP markers. Microsatellite data suggested similar patterns, but permutation tests indicated these differences were not statistically significant. The extent of differentiation and evidence of gene flow, however, suggests that the three genetic clusters are not wholly isolated from one another. The distinctions between clusters spatially align with areas of reintroduction into central Idaho and Yellowstone National Park, as well ongoing natural recolonization from adjacent populations in Canada and Montana. Wolves at the periphery of analysis areas showed more admixture than those in the core, consistent with territoriality and mating behaviors contributing to genetic structuring. We demonstrate how management history, including reintroduction efforts, and animal behavior may interact and contribute to patterns of genetic structure in wild populations.
Biologists use long-term monitoring of wildlife populations to investigate how populations change over time or in relation to extrinsic pressures. Recently, amplicon-based sequencing approaches with high-quality samples have been used to study or monitor wildlife populations in lieu of traditional microsatellite methodologies. However, the application of these techniques with lower-quality DNA sources has had mixed results and risks the loss of interoperability between microsatellites and genomic data in long-term datasets. We sought to optimize a microhaplotype panel for use with non-invasively collected wolf fecal samples, maintaining the ability to identify and match individuals across two datasets and draw familial inferences. We conducted 16 experiments to investigate pre-treatment of sample extracts, PCR1 cleaning methods, combining PCR2 with normalization using "Nate's Plates", and incubating normalization plates overnight. Additionally, we developed a quantitative PCR (qPCR) assay to quantify wolf nuclear DNA in fecal samples. We quantified 2283 fecal sample extractions on qPCR assays and ultimately genotyped 790 unique fecal samples. We retained 472 unique samples within our final dataset with an average capture rate per individual of 1.63. Finally, we successfully reconnected the two datasets by matching 66 individuals identified through scat sampling with harvest tissue genotypes. We found that noninvasive samples should have a minimum concentration of 0.2 ng/uL accompanied by efforts to reduce primer artifacts. As next generation sequencing technologies become increasingly applied in wildlife populations including using low-quality samples as we have demonstrated, special care will be required to maintain interoperability across datasets.
Reproductive output can vary widely among mammalian species. There are many drivers that affect reproductive output including evolutionary, environmental, population, social, and individual traits. Although several factors, including human-caused mortality, can affect reproductive output, we generally have a poor understanding of how such factors interact to affect reproduction, particularly in cooperative breeders. Gray wolves (Canis lupus) in Idaho, USA, are exposed to annual hunting and trapping. Thus, they are an ideal species to answer questions about how turnover within groups affects reproduction in cooperative breeders. I hypothesized that the reproductive output of wolves would be affected by individual, social, and environmental factors. Contrary to my prediction, mid-summer litter size was positively associated with wolf harvest density, suggesting a compensatory response to harvest in cooperatively breeding gray wolves. Such compensation is only partial, however, and does not fully account for all the individuals lost from harvest. At the very highest harvest densities observed, mean litter size increased nearly 28%. In contrast, mid-summer litter size was negatively associated with multiple breeding in groups, suggesting resource limitation and competition within groups. I show that characteristics associated with harvest and breeding strategies predict variations in litter size in a cooperative breeder.
Ringtails (Bassariscus astutus) are widely distributed in the western United States and across much of Mexico, yet due to their relatively low densities and cryptic nature, little is known about their basic ecology even where they are common. Recent public sightings suggest ringtails may have expanded their distribution north into southern Idaho, USA. Currently, ringtails remain unclassified in Idaho thus limiting resources and time available for population monitoring. We attempted to detect these small carnivores in southern Idaho during winter 2023. We deployed 49 camera traps with a combination of lures (i.e., trapping lure, fruit, and orange drink mix) in canyon habitats in southern Idaho near recent ringtail sightings. We detected ringtails nine times on six different camera traps. Although incidental ringtail observations increased in southern Idaho since the early 2000s, our detections were the first to result from a targeted survey effort. Given more than 20 years of incidental sightings and multiple detections during our survey, it appears that ringtails have expanded their range northward into southern Idaho and could be considered a resident species in the state. Further efforts to document reproduction, annual persistence, and an assessment of threats could be next steps if the state wildlife management agency deems it a priority and an appropriate use of resources.
Dispersal is a critical ecological and evolutionary process, yet the drivers of individual variation in emigration, particularly under human-modified conditions, remain relatively understudied. We investigate the determinants and patterns of emigration in a managed population of cooperative breeders using genetic samples from harvested individuals. We used a novel genetic approach to identify natal emigration through sibship analyses of DNA from harvested grey wolves (Canis lupus), a cooperative-breeding species, and evaluated how prey biomass, wolf density, human-caused mortality and sex influenced natal emigration across Idaho, USA, from 2017 to 2023. From our analysis of 182 sibling groups (representing packs), we evaluated natal emigration status for 224 individuals. Of these, 86 were classified as emigrants and 138 as non-dispersers. We assessed how covariates influenced the probability of emigration and evaluated sex differences in apparent dispersal distance. We found no sex differences in emigration propensity or apparent dispersal distance. Emigrants dispersed an average of 81.8 km (range: 30.0-338.9 km) from their inferred natal territories. Emigration was more likely from territories with higher prey biomass and lower wolf density, while human-caused mortality had no detectable effect. We found that ecological drivers, such as prey availability and population density, have a stronger effect on the propensity to emigrate than harvest intensity. These results highlight the importance of resource availability and population dynamics in shaping dispersal patterns in a cooperative breeder. Our study used a novel genetic method to assess natal emigration in a group-living carnivore and developed a framework broadly applicable to social systems where kin structures can be traced to dispersers. Our findings identify landscape-scale conditions that influence dispersal and can inform the management of wild populations.
Dispersal is a fundamental process that shapes social groups by affecting genetic diversity, group composition, and social dynamics through immigration and subsequent settlement. In group-living animals, dispersal involves more than just leaving 1 group and arriving at another because dispersers also need to be accepted at an established group for successful dispersal to occur. Understanding how and why new individuals integrate into established social groups remains a key question, particularly when the benefits to existing members are unclear. This question persists in part because the ecological and social conditions that shape disperser settlement remain poorly understood. We leveraged an existing harvest regime and examined 18 years of life-history data from a wild population of cooperatively breeding gray wolves (Canis lupus) to understand immigration dynamics of group-living. Specifically, we tested how social and environmental conditions within groups predicted the likelihood that a disperser successfully immigrated into a group, analyzing how breeder turnover, annual harvest, group size, and genetic relatedness influenced that decision. Turnover of breeding males had the strongest effect on the probability of disperser settlement, suggesting that the loss of key social roles may create opportunities for new individuals to join groups. We also found an interaction between group size and harvest. By quantifying conditions that shape immigrant settlement, we highlight a mechanism influencing the stability and structure of cooperatively breeding groups. Unlike studies focused on individual dispersal decisions, our research highlights how variation in ecological and social conditions shape settlement into groups by dispersers.
The behavior and abundance of sympatric predators can be affected by a complex dominance hierarchy. The strength of antagonistic interactions in predator communities is difficult to study and remains poorly understood for many predator assemblages. Predators directly and indirectly influence the broader ecosystem, so identifying the relative importance of competition, prey, and habitat in shaping predator interactions has broad conservation and management implications. We investigated space use among five predator species (black bear [Ursus americanus], bobcat [Lynx rufus], coyote [Canis latrans], mountain lion [Puma concolor], and gray wolf [Canis lupus]) across three temporal scales in northern Idaho, USA. We used camera trap data to test whether potentially subordinate predators spatially avoided dominant predators and how prey availability influenced those relationships. We found few instances of subordinate predators spatially avoiding dominant predators and only at the finest temporal scale of our analyses. Instead, habitat features generally influenced predator space use patterns at coarser scales whereas prey and competitor presence influenced space use patterns at finer scales. Co-occurrence was positively associated between coyotes and bobcats at coarser timescales and between mesopredators and apex predators at finer timescales. Bobcats and mountain lions temporarily delayed the use of sites recently visited by coyotes and black bears, respectively. And all predator species used sites sooner following the detection of a competitor in areas with higher relative abundances of prey (primarily white-tailed deer [Odocoileus virginianus]). Our results suggest attraction to shared habitats and prey resources influenced space use in the predator community more than avoidance of competitors. We propose that the effects of interspecific interactions on predator distributions were most evident for mesopredators because their trophic position requires balancing risks and rewards associated with prey, apex predators, and other mesopredators. In addition, relatively high densities of a common prey source likely facilitated the spatial coexistence in this predator community. Our study demonstrates the value of simultaneously assessing multiple interspecific interactions across different spatiotemporal scales to discern relationships within the predator guild.
Population monitoring is essential to document recovery efforts for threatened and endangered species. Mexican wolves ( Canis lupus baileyi ) are an endangered subspecies of gray wolves that historically occupied large portions of the American Southwest and Mexico. Recently, the Mexican wolf population in the United States has been growing rapidly and traditional approaches for population monitoring (e.g., capture and radio collaring) are becoming difficult and expensive as wolves expand into new areas. We developed predictive models of pup‐rearing habitat (i.e., den and rendezvous sites) that could help guide future population monitoring efforts. We located 255 den sites and 129 rendezvous sites in Arizona and New Mexico, USA (1998–2023) using tracking collars and site visits. We sampled habitat conditions in wolf‐occupied regions of Arizona and New Mexico and fit logistic regressions to these data following a use–available study design to estimate resource selection functions (RSF) for den and rendezvous sites. We hypothesized wolves would select areas that offered greater physical protection, lower human‐disturbance, and access to reliable water sources for pup‐rearing but that the relative importance of these features would differ between the denning and rendezvous site seasons. Mexican wolves selected den sites at higher elevations in steeper and rougher terrain that were closer to permanent waterbodies but farther from rural roads. Selection of rendezvous sites was also associated with higher elevations and proximity to waterbodies but varied with availability of green leaf biomass on the landscape. While still highly predictive, our rendezvous site model was less predictive than our den model (Spearman's correlation averaged 0.81 [SE = 0.05] vs. 0.90 [SE = 0.03], respectively), possibly because water and green leaf biomass are more spatially diffuse and variable because of monsoonal rains during the rendezvous site season. Our results suggest that terrain features associated with physical protection and access to reliable water were most important in characterizing suitable pup‐rearing habitat for Mexican wolves. By predicting suitable den and rendezvous site habitat across portions of the Mexican Wolf Experimental Population Area, our models can help guide future population monitoring by reducing the total search area when surveying for wolves and increase the probability of detecting all members of a pack.
In the rain-snow transition zone of the Pacific Northwest, climate change is expected to alter the incidence of rain-on-snow and freeze-thaw events, which will change snow density and hardness dynamics. In winter, the ability of economically and ecologically important wildlife species, such as deer (Odocoileus spp.), to efficiently move through the landscape and access forage is mediated by snow conditions. Therefore, snow properties such as density and hardness can directly affect how energetically costly it is for these animals to survive. However, little is known about whether and how ungulates use habitats based on snow density and hardness. We deployed a stratified network of remote camera stations in complex forested terrain in Latah County, Idaho, USA, to remotely measure snow depth and detect deer. We also collected snow density and hardness measurements throughout the winter. We used these data to determine the degree to which the probability of deer presence at cameras could be explained by snow conditions and air temperature. Snow depth and density had negative relationships with the probability of deer presence, while ram resistance (a proxy for snow hardness) had a marginal positive effect. We were able to estimate snow conditions important to deer in winter 2020-2021 primarily using data obtained from cameras. This provides an important proof-of-concept that can be applied at different sites and climate conditions to gain a deeper understanding of how deer are affected by snowpack properties. These methods can be used by managers to determine how ungulates are affected by snow depth, density, and hardness collectively and subsequently inform ungulate management in a changing climate.
Wildlife populations are increasingly threatened by human activities. Most studies, however, are often short in duration or do not encompass the large spatial extent necessary to measure the potential effects of human activities on population vital rates. Furthermore, the life history features of species with high fecundity and excellent dispersal capabilities can act as buffers against the potential negative effects of human activities on their populations. We used a 30-year dataset of genetic samples from gray wolves (Canis lupus) in Alaska, USA, to examine genetic connectivity and diversity between National Park units separated by a region with recurrent human-caused mortality. We found that the two protected populations were genetically similar and that dispersal events occurred between them even though they are > 450 km apart. We posit that intact ecosystems and a history of continuous distribution of wolves surrounding the affected regions likely maintained the genetic connectivity of wolves in the two protected areas.
Individual behaviors are influenced by environmental, genetic, and demographic factors. Some animals choose to live in groups and cooperatively breed, and their behaviors can change depending on dynamic factors such as group size and composition that affect group persistence. In Idaho, USA, gray wolves ( Canis lupus ) are harvested annually, providing an opportunity to investigate the effects of harvest and seasonal behaviors on a population of cooperative breeders. These annual hunting and trapping seasons overlap with the dispersal and breeding periods for wolves and we do not know how harvest affects the vulnerability of different sex and age classes during these important biological periods. We applied 9 years (2009–2018) of genetic, age, and harvest data from harvested wolves to investigate how behaviors (dispersal and breeding) and biological drivers might influence the vulnerability of wolves to harvest. We created pedigrees from genotypes of non‐invasively collected scats to estimate the expected proportion of the wolf population composed of 3 different age classes (pup, yearling, and sexually mature or ≥2 years old) and compared them to the observed number of each age class harvested during biologically significant periods (i.e., dispersal and breeding). We found that pups were more vulnerable to harvest in December when wolf harvest transitioned largely to trapping (accounts for 66% of harvest), and found evidence that adults were more vulnerable to harvest during their breeding season in January and February. In contrast, we found no difference in the expected versus observed number of wolves ≥2 years old in the harvest during peak dispersal season (December), or in the expected versus observed number of yearlings in the harvest during September and October when pups are mobile and groups of wolves abandon the use of pup‐rearing sites. Some age classes were disproportionally harvested during certain periods for specific years, but this was not consistent across all years, suggesting there is more to learn about the vulnerability of different age classes to harvest. We found harvest can disproportionally affect some demographic classes of individuals depending on year, biological period, and harvest type. With wolves continuing to recolonize historical ranges, our approach can benefit managers and future studies with the goal of identifying how interannual harvest affects groups of wolves.
Genetic diversity is an important driver affecting the health of wildlife populations. In cooperatively breeding species, human impacts and breeder turnover can affect genetic diversity in groups. We generally do not have strong inferences about how the genetic composition of a group changes through time as individuals are lost (e.g., die, emigrate) or adopted (e.g., immigrate). I wanted to know how breeder turnover, group size, and harvest affected the fluctuation of unique alleles in groups of gray wolves (Canis lupus) in Idaho, USA, during 2008–2020. Turnover of breeding males was strongly associated with allelic change in groups. Turnover of breeding females also had a strong association with allelic change in groups, but was not the most supported model. Harvest was strongly correlated with breeding female turnover but not breeding male turnover. Outside of breeding female turnover, harvest generally had little effect on allelic change in groups. Groups rarely adopted new individuals unless there was a breeding vacancy. I show that over time groups gain and lose alleles in roughly equal proportions, but there are episodic changes to alleles in groups as a function of breeding male turnover. These findings have implications for how we define and evaluate group persistence and breeder lineages in cooperative breeders. Such definitions have important implications for studying the evolution and maintenance of cooperative breeding. It may be beneficial to define characteristics and vital rates of groups based, at least in part, on their underlying genetics when such information can be obtained.
Female and male cooperative breeders can use different strategies to maximize reproduction and fitness over their lifetimes. Answering questions about fitness in cooperative breeders requires long-term studies as well as complete data on group composition and size which can be exceedingly difficult to obtain. Using a long-term genetic data set of complete group pedigrees, I asked how lifetime reproductive characteristics of female and male gray wolves (Canis lupus) differed. I predicted that genetic relatedness to helpers would be higher for females than males due to philopatric behavior of female wolves, group size would be similar between the sexes, females would inherit breeding positions from within groups more often than males due to differences in dispersal strategies between the sexes, males would have more lifetime mates and produce more young than females because of polygamy, and females would breed for more years than males due to the likelihood that females would still breed (with a new partner) after a mate died or was expelled from the group. I documented complete lifetime breeding histories for 11 male and 18 female wolves in Idaho, United States, 2008 to 2018. Genetic relatedness to helpers, group size, number of mates, pups, and years breeding did not differ between the sexes. Females, however, inherited breeding positions within groups far more often than males. Individuals who secured breeding positions generally reproduced for 2 seasons and commonly had more than 1 partner during their lifetimes if they were able to maintain their breeding position longer. Direct fitness varied greatly within female and male breeding wolves. Las hembras y los machos que presentan crianza cooperativa pueden utilizar diferentes estrategias para maximizar la reproducci & oacute;n y la aptitud biol & oacute;gica a lo largo de sus vidas. Responder preguntas sobre la aptitud biol & oacute;gica de la crianza cooperativa requiere estudios a largo plazo, as & iacute; como datos completos sobre la composici & oacute;n y el tama & ntilde;o del grupo, que pueden ser extremadamente dif & iacute;ciles de obtener. Utilizando un conjunto de datos gen & eacute;ticos de largo plazo de genealog & iacute;as grupales completas, investigu & eacute; en qu & eacute; se diferenciaban las caracter & iacute;sticas reproductivas a lo largo de la vida de las hembras y los machos de los lobos grises (Canis lupus). Predije que la relaci & oacute;n gen & eacute;tica con los ayudantes ser & iacute;a mayor para las hembras que para los machos; el tama & ntilde;o del grupo ser & iacute;a similar entre los sexos; las hembras heredar & iacute;an posiciones reproductivas dentro de los grupos con m & aacute;s frecuencia que los machos; los machos tendr & iacute;an m & aacute;s parejas a lo largo desu vida y producir & iacute;an m & aacute;s cr & iacute;as que las hembras debido a la poligamia; y que las hembras se reproducir & iacute;an durante m & aacute;s a & ntilde;os que los machos. Document & eacute; la historia reproductiva a lo largo de la vida de 11 lobos machos y 18 hembras en Idaho, EE. UU., 2008-2018. La relaci & oacute;n gen & eacute;tica con los ayudantes, el tama & ntilde;o del grupo, el n & uacute;mero de parejas, las cr & iacute;as y los a & ntilde;os de reproducci & oacute;n no difirieron entre los sexos. Sin embargo, las hembras heredaron posiciones reproductivas dentro de los grupos con mucha m & aacute;s frecuencia que los machos. Los individuos que aseguraron posiciones reproductivas generalmente se reprodujeron durante dos temporadas y com & uacute;nmente tuvieron m & aacute;s de una pareja durante su vida si pudieron mantener su posici & oacute;n reproductiva por m & aacute;s tiempo. La aptitud biol & oacute;gica directa vari & oacute; mucho entre las hembras y los machos de los lobos reproductores.
Nonbreeding helpers can greatly improve the survival of young and the reproductive fitness of breeders in many cooperatively breeding species. Breeder turnover, in turn, can have profound effects on dispersal decisions made by helpers. Despite its importance in explaining group size and predicting the population demography of cooperative breeders, our current understanding of how individual traits influence animal behavior after disruptions to social structure is incomplete particularly for terrestrial mammals. We used 12 yr of genetic sampling and group pedigrees of gray wolves (Canis lupus) in Idaho, USA, to ask questions about how breeder turnover affected the apparent decisions by mature helpers (>= 2-yr-old) to stay or leave a group over a 1-yr time interval. We found that helpers showed plasticity in their responses to breeder turnover. Most notably, helpers varied by sex and appeared to base dispersal decisions on the sex of the breeder that was lost as well. Male and female helpers stayed in a group slightly more often when there was breeder turnover of the same sex, although males that stayed were often recent adoptees in the group. Males, however, appeared to remain in a group less often when there was breeding female turnover likely because such vacancies were typically filled by related females from the males' natal group (i.e. inbreeding avoidance). We show that helpers exploit instability in the breeding pair to secure future breeding opportunities for themselves. The confluence of breeder turnover, helper sex, and dispersal and breeding strategies merge to influence group composition in gray wolves. For animals that live and breed in groups, losing a breeder can have profound effects on the remaining group members. We show that nonbreeding helpers decide to leave or remain in a group based on the sex of the breeder who is lost. Furthermore, male and female nonbreeding helpers use different strategies when deciding to stay or go.
Mange is a skin disease caused by mites that parasitize an animal's skin, often yielding inflamed immune responses and hair loss. At a population level, mange may reduce survival and cause population declines. Many forms of mange can be treated quite effectively when an animal is in hand; however, this is not often feasible for many free-ranging wildlife populations. Some animals, particularly territorial carnivores, will rub or roll to scent mark and transmit information about their presence to other individuals. We posited that rub stations comprised, in part, of anthelmintic medication and foreign scents that induce rubbing could be used to remotely treat mange in the wild. We deployed 39 rub stations containing lure and dye in Santa Monica Mountains National Recreation Area, Southern California, USA, October-November 2022. Carnivores rubbed or rolled at >97% of rub stations, with coyotes (Canis latrans), gray foxes (Urocyon cinereoargenteus), and bobcats (Lynx rufus) being the most abundant species. Time to first rub or roll was generally <1 wk. Several sympatric species (e.g., mule deer, Odocoileus hemionus) were detected at rub stations but did not rub. Our pilot test provides strong evidence that treating mange in wild carnivores may be possible using the remote medicinal rub stations we describe. Future efforts to add medicine to rub stations and monitor for a change in mange prevalence are a logical next step.
Abstract In cooperatively breeding carnivores, breeders are vital to perpetuating the group; the death or removal of an individual breeder can greatly affect group composition, genetic content, and short‐term population growth. Understanding the number of breeders harvested and timing of harvest can increase our knowledge of how mortality affects groups of cooperative breeders. Gray wolves (Canis lupus) in Idaho, USA, are exposed to annual harvest and are an ideal species for studying the effects of harvest on breeder turnover. We combined genotypes from tissue samples of harvested wolves with parentage analyses and cementum annuli ages and estimated when and how many breeding wolves were harvested. We genotyped and aged 229 adults and 203 pups using tissue and tooth samples from wolves harvested between 2014 and 2016. We identified a minimum count of 33 breeders in the harvest and found that they were disproportionately harvested more during the breeding season. We estimated that a minimum of ~14.5% of adult wolves harvested annually, or approximately 1 in 7, were breeders. We posit their behavior during breeding season may increase their vulnerability to harvest. By linking animal life history with vulnerability to human‐caused mortality we show that managers could structure harvest seasons so there is less overlap with wolves’ breeding season if there is concern about the demographic consequences of harvesting breeders.
Human-caused mortality can be pervasive and even highly selective for individuals in groups of cooperative breeders. Many studies of cooperative breeders, however, do not address human-caused mortality. Similarly, studies focused on the effects of human-caused mortality on wildlife populations often do not consider the ecology of cooperative breeders. We searched the literature and identified 58 studies where human-caused mortality affected a group characteristic, vital rate, or population state of a cooperative breeder. Of studies reporting population growth or decline, 80% reported a link between human-caused mortality and population declines in cooperative breeders. Such studies often did not identify the mechanism behind population declines, but 28% identified concurrent declines in adult survival and another 21% reported concurrent declines in recruitment or reproduction. There was little overlap between the cooperative breeding and human-caused mortality literatures, limiting our ability to accrue knowledge. Future work would be beneficial if it (i) identified the vital rate(s) causing population declines, (ii) leveraged management actions such as lethal removal to ask questions about the ecology of group-living in cooperative breeders, and (iii) used insights from cooperative breeding theory to inform management actions and conservation of group-living species.
Knowledge of snow cover distribution and disappearance dates over a wide range of scales is imperative for understanding hydrological dynamics and for habitat management of wildlife species that rely on snow cover. Identification of snow refugia, or places with relatively late snow disappearance dates (SDDs) compared to surrounding areas, is especially important as climate change alters snow cover timing and duration. The purpose of this study was to increase understanding of snow refugia in complex terrain spanning the rain-snow transition zone at fine spatial and temporal scales. To accomplish this objective, we used remote cameras to provide relatively high temporal and spatial resolution measurements on snowpack conditions. We built linear models to relate SDDs at the monitoring sites to topoclimatic and canopy cover metrics. One model to quantify SDDs included elevation, aspect, and an interaction between canopy cover and cold-air pooling potential. High-elevation, north-facing sites in cold-air pools (CAPs) had the latest SDDs, but isolated lower-elevation points also exhibited relatively late potential SDDs. Importantly, canopy cover had a much stronger effect on SDDs in CAPs than in non-CAPs, indicating that best practices in forest management for snow refugia could vary across microtopography. A second model that included in situ hydroclimate observations (December – February (DJF) temperature and March 1 snow depth) indicated that March 1 snow depth had little impact on SDD at the coldest winter temperatures, and that DJF temperatures had a stronger effect on SDD at lower snow depths, implying that the relative importance of snowfall and temperature could vary across hydroclimatic contexts in their impact on snow refugia. This new understanding of factors influencing snow refugia can guide forest management actions to increase snow retention and inform management of snow-dependent wildlife species in complex terrain.
Gray wolf (Canis lupus) recovery and conservation has been a remarkable success over the last 30 years in the United States. Remarkable success yields remarkable challenges, however. As populations expand, wolves will colonize more human-dominated landscapes and face numerous challenges, such as fragmented habitats, barriers to dispersal, and increased encounters with humans, pets, and livestock. In such areas, conflicts between humans and wolves will increase. We summarize several major scientific and social challenges that wolf conservation, recovery, and management will face in the coming years. In addition, we suggest actions to help address each challenge. Future wolf conservation in the United States will be affected by the ability of managers to predict colonization and dispersal dynamics, to reduce hybridization and disease transmission, to mitigate and deter wolf-livestock conflicts, to harvest wolves sustainably while satisfying diverse stakeholders, to avert a reduction in tolerance for wolves due to a disinterest in nature, and to engage diverse stakeholders in wolf conservation to avoid management by ballot initiative or legislative and judicial decrees.