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Abstract Mapped representations of species−habitat relationships often underlie approaches to prioritize area‐based conservation strategies to meet conservation goals for biodiversity. Generally a single surrogate species is used to inform conservation design, with the assumption that conservation actions for an appropriately selected species will confer benefits to a broader community of organisms. Emerging conservation frameworks across western North America are now relying on derived measures of intactness from remotely sensed vegetation data, wholly independent from species data. Understanding the efficacy of species‐agnostic planning approaches is a critical step to ensuring the robustness of emerging conservation designs. We developed an approach to quantify ‘strength of surrogacy’, by applying prioritization algorithms to previously developed species models, and measuring their coverage provided to a broader wildlife community. We used this inference to test the relative surrogacy among a suite of species models used for conservation targeting in the endangered grasslands of the Northern Sagebrush Steppe, where careful planning can help stem the loss of private grazing lands to cultivation. In this test, we also derived a simpler surrogate of intact rangelands without species data for conservation targeting, along with a measure of combined migration representative of key areas for connectivity. Our measure of intactness vastly outperformed any species model as a surrogate for conservation, followed by that of combined migration, highlighting the efficacy of strategies that target large and intact rangeland cores for wildlife conservation and restoration efforts.

The reintroduction of extirpated species is a frequent tactic in rewilding projects because of the functional role species play in maintaining ecosystem health. Despite their potential to benefit both ecosystems and society, however, most well-known species reintroductions have adopted an eco-centric, “nature-in-people-out” approach. Rewilding theory and practitioners acknowledge that ignoring the role Indigenous people did and might once again play in shaping the distribution, abundance, movements, behavior, and health of wild species and ecosystems, is limiting. In this case study, we describe the technical steps we took and how Indigenous knowledge, ceremony, and cultural monitoring were woven into the recent reintroduction of plains bison to Canada’s Banff National Park. Six years later, the reintroduced bison herd has grown from 16 to >100 animals, ranges mostly within 30 km of the release site, and, if current growth continues, will likely be managed with Indigenous harvesting. Transboundary bison policy differences are shifting and may lead to bison being more sustainable. The ecocultural approach, therefore, has increased the resilience of our rewilding project.

Arctic vegetation communities are rapidly changing with climate warming, which impacts wildlife, carbon cycling, and climate feedbacks. Accurately monitoring vegetation change is thus crucial, but scale mismatches between field and satellite-based monitoring cause challenges. Remote sensing from unmanned aerial vehicles (UAVs) has emerged as a bridge between field data and satellite-based mapping. We assessed the viability of using high-resolution UAV imagery and UAV-derived Structure from Motion to predict cover, height, and aboveground biomass (henceforth biomass) of Arctic plant functional types (PFTs) across a range of vegetation community types. We classified imagery by PFT, estimated cover and height, and modeled biomass from UAV-derived volume estimates. Predicted values were compared to field estimates to assess results. Cover was estimated with a root-mean-square error (RMSE) of 6.29%–14.2%, and height was estimated with an RMSE of 3.29–10.5 cm depending on the PFT. Total aboveground biomass was predicted with an RMSE of 220.5 g m−2, and per-PFT RMSE ranged from 17.14 to 164.3 g m−2. Deciduous and evergreen shrub biomass was predicted most accurately, followed by lichen, graminoid, and forb biomass. Our results demonstrate the effectiveness of using UAVs to map PFT biomass, which provides a link towards improved mapping of PFTs across large areas using earth observation satellite imagery.

Abstract Linear features are pervasive across the boreal forest of Canada, negatively impacting several wildlife species. Understanding how wildlife responds to different types and characteristics of linear features is necessary for coordinated landscape restoration. Currently, linear feature restoration is focused on recovering threatened woodland caribou (Rangifer tarandus) which may have unintended impacts on other boreal species like moose (Alces alces). Understanding how moose respond to different linear features can help ensure restoration is targeted and effective. We used GPS data from seven moose collected between 2008 and 2010 to investigate response to linear features and to determine how moose response was influenced by characteristics of linear features like the surrounding habitat and regeneration. At the landscape scale, moose selected areas closer to seismic lines when they were in areas with lower densities of seismic lines and higher densities of harvest blocks and wildfires. This response was stronger during winter. Moose selected areas closer to pipelines when they were in areas with lower densities of other linear features, harvest blocks, and wildfires and were indifferent to roads at the population‐level. At the fine scale, during winter, moose selected areas closer to seismic lines regardless of vegetation height or the surrounding habitat, but were indifferent to seismic lines during summer, and were indifferent to roads and pipelines during summer and winter. Combined, our results suggest that there are characteristics of seismic lines which make them attractive to moose regardless of the regeneration height on the seismic lines, providing further evidence that effective linear feature restoration will need to address the fact that linear features increase landscape permeability and provide forage for multiple boreal wildlife species. Our results also further illustrate the importance of considering how linear feature restoration efforts focused on caribou may shift the distribution of other boreal wildlife species. Ultimately, conservation efforts for threatened species should recognize that conservation efforts focused on one species may have unintended consequences for interacting species.

Abstract Although global change can reshape ecosystems by triggering cascading effects on food webs, indirect interactions remain largely overlooked. Climate‐ and land‐use‐induced changes in landscape cause shifts in vegetation composition, which affect entire food webs. We used simulations of forest dynamics and movements of interacting species, parameterized by empirical observations, to predict the outcomes of global change on a large‐mammal food web in the boreal forest. We demonstrate that climate‐ and land‐use‐induced changes in forest landscapes exacerbate asymmetrical apparent competition between moose and threatened caribou populations through wolf predation. Although increased prey mortalities came from both behavioral and numerical responses, indirect effects from numerical responses had an overwhelming effect. The increase in caribou mortalities was exacerbated by the cumulating effects of land use over the short term and climate change impacts over the long term, with higher impact of land use. Indirect trophic interactions will be key to understanding community dynamics under global change.

Abstract Background Global increases in human activity threaten connectivity of animal habitat and populations. Protection and restoration of wildlife habitat and movement corridors require robust models to forecast the effects of human activity on movement behaviour, resource selection, and connectivity. Recent research suggests that animal resource selection and responses to human activity depend on their behavioural movement state, with increased tolerance for human activity in fast states of movement. Yet, few studies have incorporated state-dependent movement behaviour into analyses of Merriam connectivity, that is individual-based metrics of connectivity that incorporate landscape structure and movement behaviour. Methods We assessed the cumulative effects of anthropogenic development on multiple movement processes including movement behaviour, resource selection, and Merriam connectivity. We simulated movement paths using hidden Markov movement models and step selection functions to estimate habitat use and connectivity for three landscape scenarios: reference conditions with no anthropogenic development, current conditions, and future conditions with a simulated expansion of towns and recreational trails. Our analysis used 20 years of grizzly bear (Ursus arctos) and gray wolf (Canis lupus) movement data collected in and around Banff National Park, Canada. Results Carnivores increased their speed of travel near towns and areas of high trail and road density, presumably to avoid encounters with people. They exhibited stronger avoidance of anthropogenic development when foraging and resting compared to travelling and during the day compared to night. Wolves exhibited stronger avoidance of anthropogenic development than grizzly bears. Current development reduced the amount of high-quality habitat between two mountain towns by more than 35%. Habitat degradation constrained movement routes around towns and was most pronounced for foraging and resting behaviour. Current anthropogenic development reduced connectivity from reference conditions an average of 85%. Habitat quality and connectivity further declined under a future development scenario. Conclusions Our results highlight the cumulative effects of anthropogenic development on carnivore movement behaviour, habitat use, and connectivity. Our strong behaviour-specific responses to human activity suggest that conservation initiatives should consider how proposed developments and restoration actions would affect where animals travel and how they use the landscape.

Abstract Summer diets are crucial for large herbivores in the subarctic and are affected by weather, harassment from insects and a variety of environmental changes linked to climate. Yet, understanding foraging behavior and diet of large herbivores is challenging in the subarctic because of their remote ranges. We used GPS video‐camera collars to observe behaviors and summer diets of the migratory Fortymile Caribou Herd (Rangifer tarandus granti) across Alaska, USA and the Yukon, Canada. First, we characterized caribou behavior. Second, we tested if videos could be used to quantify changes in the probability of eating events. Third, we estimated summer diets at the finest taxonomic resolution possible through videos. Finally, we compared summer diet estimates from video collars to microhistological analysis of fecal pellets. We classified 18,134 videos from 30 female caribou over two summers (2018 and 2019). Caribou behaviors included eating (mean = 43.5%), ruminating (25.6%), travelling (14.0%), stationary awake (11.3%) and napping (5.1%). Eating was restricted by insect harassment. We classified forage(s) consumed in 5,549 videos where diet composition (monthly) highlighted a strong tradeoff between lichens and shrubs; shrubs dominated diets in June and July when lichen use declined. We identified 63 species, 70 genus and 33 family groups of summer forages from videos. After adjusting for digestibility, monthly estimates of diet composition were strongly correlated at the scale of the forage functional type (i.e., forage groups composed of forbs, graminoids, mosses, shrubs and lichens; r = 0.79, p

Abstract The recovery of carnivore populations in North American has consequences for trophic interactions and population dynamics of prey. In addition to direct effects on prey populations through killing, predators can influence prey behavior by imposing the risk of predation. The mechanisms through which patterns of space use by predators are linked to behavioral response by prey and nonconsumptive effects on prey population dynamics are poorly understood. Our goal was to characterize population‐ and individual‐level patterns of resource selection by elk (Cervus canadensis) in response to risk of wolves (Canis lupus) and mountain lions (Puma concolor) and evaluate potential nonconsumptive effects of these behavioral patterns. We tested the hypothesis that individual elk risk‐avoidance behavior during summer would result in exposure to lower‐quality forage and reduced body fat and pregnancy rates. First, we evaluated individuals' second‐order and third‐order resource selection with a used‐available sampling design. At the population level, we found evidence for a positive relationship between second‐ and third‐order selection and forage, and an interaction between forage quality and mountain lion risk such that the relative probability of use at low mountain lion risk increased with forage quality but decreased at high risk at both orders of selection. We found no evidence of a population‐level trade‐off between forage quality and wolf risk. However, we found substantial among‐individual heterogeneity in resource selection patterns such that population‐level patterns were potentially misleading. We found no evidence that the diversity of individual resource selection patterns varied predictably with available resources, or that patterns of individual risk‐related resource selection translated into biologically meaningful changes in body fat or pregnancy rates. Our work highlights the importance of evaluating individual responses to predation risk and predator hunting technique when assessing responses to predators and suggests nonconsumptive effects are not operating at a population scale in this system.

Abstract The presence of many pathogens varies in a predictable manner with latitude, with infections decreasing from the equator towards the poles. We investigated the geographic trends of pathogens infecting a widely distributed carnivore: the gray wolf (Canis lupus). Specifically, we investigated which variables best explain and predict geographic trends in seroprevalence across North American wolf populations and the implications of the underlying mechanisms. We compiled a large serological dataset of nearly 2000 wolves from 17 study areas, spanning 80° longitude and 50° latitude. Generalized linear mixed models were constructed to predict the probability of seropositivity of four important pathogens: canine adenovirus, herpesvirus, parvovirus, and distemper virus—and two parasites: Neospora caninum and Toxoplasma gondii. Canine adenovirus and herpesvirus were the most widely distributed pathogens, whereas N. caninum was relatively uncommon. Canine parvovirus and distemper had high annual variation, with western populations experiencing more frequent outbreaks than eastern populations. Seroprevalence of all infections increased as wolves aged, and denser wolf populations had a greater risk of exposure. Probability of exposure was positively correlated with human density, suggesting that dogs and synanthropic animals may be important pathogen reservoirs. Pathogen exposure did not appear to follow a latitudinal gradient, with the exception of N. caninum. Instead, clustered study areas were more similar: wolves from the Great Lakes region had lower odds of exposure to the viruses, but higher odds of exposure to N. caninum and T. gondii; the opposite was true for wolves from the central Rocky Mountains. Overall, mechanistic predictors were more informative of seroprevalence trends than latitude and longitude. Individual host characteristics as well as inherent features of ecosystems determined pathogen exposure risk on a large scale. This work emphasizes the importance of biogeographic wildlife surveillance, and we expound upon avenues of future research of cross-species transmission, spillover, and spatial variation in pathogen infection.

Abstract Background Temperatures in arctic-boreal regions are increasing rapidly and pose significant challenges to moose (Alces alces), a heat-sensitive large-bodied mammal. Moose act as ecosystem engineers, by regulating forest carbon and structure, below ground nitrogen cycling processes, and predator-prey dynamics. Previous studies showed that during hotter periods, moose displayed stronger selection for wetland habitats, taller and denser forest canopies, and minimized exposure to solar radiation. However, previous studies regarding moose behavioral thermoregulation occurred in Europe or southern moose range in North America. Understanding whether ambient temperature elicits a behavioral response in high-northern latitude moose populations in North America may be increasingly important as these arctic-boreal systems have been warming at a rate two to three times the global mean. Methods We assessed how Alaska moose habitat selection changed as a function of ambient temperature using a step-selection function approach to identify habitat features important for behavioral thermoregulation in summer (June–August). We used Global Positioning System telemetry locations from four populations of Alaska moose (n = 169) from 2008 to 2016. We assessed model fit using the quasi-likelihood under independence criterion and conduction a leave-one-out cross validation. Results Both male and female moose in all populations increasingly, and nonlinearly, selected for denser canopy cover as ambient temperature increased during summer, where initial increases in the conditional probability of selection were initially sharper then leveled out as canopy density increased above ~ 50%. However, the magnitude of selection response varied by population and sex. In two of the three populations containing both sexes, females demonstrated a stronger selection response for denser canopy at higher temperatures than males. We also observed a stronger selection response in the most southerly and northerly populations compared to populations in the west and central Alaska. Conclusions The impacts of climate change in arctic-boreal regions increase landscape heterogeneity through processes such as increased wildfire intensity and annual area burned, which may significantly alter the thermal environment available to an animal. Understanding habitat selection related to behavioral thermoregulation is a first step toward identifying areas capable of providing thermal relief for moose and other species impacted by climate change in arctic-boreal regions.

Migration is typically thought to be an evolved trait driven by responses to forage or predation, but recent studies have demonstrated avoidance of parasitism can also affect success of migratory tactics within a population. We evaluated hypotheses of how migration alters parasite exposure in a partially migratory elk (Cervus canadensis) population in and adjacent to Banff National Park, Alberta, Canada. Equal numbers of elk remain year-round on the winter range or migrate to summer range. We quantified diversity and abundance of parasites in faecal elk pellets, and prevalence (number of infected individuals) and intensity (egg counts) of giant liver fluke eggs (Fascioloides magna) in faeces across migratory tactics. We tested whether giant liver fluke intensity in faeces was affected by elk use of wetlands, elevation, forage biomass, and elk concentration in the previous summer. We rejected the “migratory escape” hypothesis that suggests migration allowed elk to escape parasite exposure because migrant elk had the highest richness and evenness of parasite groups. We also rejected the hypothesis that prevalence was highest at highest summer densities because higher-density resident elk had the lowest diversity and giant liver fluke egg presence and intensity. Instead, the high prevalence and intensity of giant liver flukes in migrants was consistent with both the hypothesis of “environmental tracking”, because elk that migrated earlier may expose themselves to favourable parasite conditions, and with the “environmental sampling” hypothesis, because giant liver fluke intensity increased with increased exposure to secondary host habitat (i.e., wetland). Our results indicate that differential exposure of different migratory tactics that leave the winter range has a greater influence on parasites than the concentration of elk that reside on the winter range year-round.

Abstract Density‐dependent competition for food reduces vital rates, with juvenile survival often the first to decline. A clear prediction of food‐based, density‐dependent competition for large herbivores is decreasing juvenile survival with increasing density. However, competition for enemy‐free space could also be a significant mechanism for density dependence in territorial species. How juvenile survival is predicted to change across density depends critically on the nature of predator–prey dynamics and spatial overlap among predator and prey, especially in multiple‐predator systems. Here, we used a management experiment that reduced densities of a generalist predator, coyotes, and specialist predator, mountain lions, over a 5‐year period to test for spatial density dependence mediated by predation on juvenile mule deer in Idaho, USA. We tested the spatial density‐dependence hypothesis by tracking the fate of 251 juvenile mule deer, estimating cause‐specific mortality, and testing responses to changes in deer density and predator abundance. Overall juvenile mortality did not increase with deer density, but generalist coyote‐caused mortality did, but not when coyote density was reduced experimentally. Mountain lion‐caused mortality did not change with deer density in the reference area in contradiction of the food‐based competition hypothesis, but declined in the treatment area, opposite to the pattern of coyotes. These observations clearly reject the food‐based density‐dependence hypothesis for juvenile mule deer. Instead, our results provide support for the spatial density‐dependence hypothesis that competition for enemy‐free space increases predation by generalist predators on juvenile large herbivores.

Abstract There is growing evidence that prey perceive the risk of predation and alter their behavior in response, resulting in changes in spatial distribution and potential fitness consequences. Previous approaches to mapping predation risk across a landscape quantify predator space use to estimate potential predator‐prey encounters, yet this approach does not account for successful predator attack resulting in prey mortality. An exception is a prey kill site that reflects an encounter resulting in mortality, but obtaining information on kill sites is expensive and requires time to accumulate adequate sample sizes. We illustrate an alternative approach using predator scat locations and their contents to quantify spatial predation risk for elk (Cervus canadensis) from multiple predators in the Rocky Mountains of Alberta, Canada. We surveyed over 1300 km to detect scats of bears (Ursus arctos/U. americanus), cougars (Puma concolor), coyotes (Canis latrans), and wolves (C. lupus). To derive spatial predation risk, we combined predictions of scat‐based resource selection functions (RSFs) weighted by predator abundance with predictions that a predator‐specific scat in a location contained elk. We evaluated the scat‐based predictions of predation risk by correlating them to predictions based on elk kill sites. We also compared scat‐based predation risk on summer ranges of elk following three migratory tactics for consistency with telemetry‐based metrics of predation risk and cause‐specific mortality of elk. We found a strong correlation between the scat‐based approach presented here and predation risk predicted by kill sites and (r = .98, p

Wide-ranging animals, including migratory species, are significantly threatened by the effects of habitat fragmentation and habitat loss. In the case of terrestrial mammals, this results in nearly a quarter of species being at risk of extinction. Caribou are one such example of a wide-ranging, migratory, terrestrial, and endangered mammal. In populations of caribou, the proportion of individuals considered as "migrants" can vary dramatically. There is therefore a possibility that, under the condition that migratory behavior is genetically determined, those individuals or populations that are migratory will be further impacted by humans, and this impact could result in the permanent loss of the migratory trait in some populations. However, genetic determination of migration has not previously been studied in an endangered terrestrial mammal. We examined migratory behavior of 139 GPS-collared endangered caribou in western North America and carried out genomic scans for the same individuals. Here we determine a genetic subdivision of caribou into a Northern and a Southern genetic cluster. We also detect >50 SNPs associated with migratory behavior, which are in genes with hypothesized roles in determining migration in other organisms. Furthermore, we determine that propensity to migrate depends upon the proportion of ancestry in individual caribou, and thus on the evolutionary history of its migratory and sedentary subspecies. If, as we report, migratory behavior is influenced by genes, caribou could be further impacted by the loss of the migratory trait in some isolated populations already at low numbers. Our results indicating an ancestral genetic component also suggest that the migratory trait and their associated genetic mutations could not be easily re-established when lost in a population.

Abstract Founded in 1993, the Yellowstone to Yukon (Y2Y) vision was one of the earliest large‐landscape conservation visions. Despite growing recognition of large‐landscape conservation strategies, there have been few tests to date of conservation gains achieved through such approaches. We tested for conservation gains in the Y2Y region of North America following initiation of the Y2Y conservation vision in 1993 using a counterfactual spatiotemporal comparison and tracking change in five different conservation metrics. First, we enumerated the area of land within Y2Y in designated protected areas. We then compared the rate of change of protected area growth before‐ and after‐initiation of Y2Y in 1993 and to two adjacent counterfactual regions. Protected areas in the Y2Y grew by 7.8%, increasing by 107,289 km2, exceeding the Aichi target of 17% of the area under protection by 2018. More importantly, the rate of protected area growth increased 90% following initiation of the Y2Y large‐landscape conservation vision in 1993, whereas protected area growth declined in adjacent regions, or remained constant throughout North America. Sustained growth in protected areas and private land conservation was complemented by expansion of endangered grizzly bears in the U.S. portion of Y2Y, the greatest global expansion from zero to at least 117 wildlife road‐crossing structures and growing mainstreaming coverage of the Y2Y vision. Our counterfactual comparison provides valuable evidence that large‐landscape conservation strategies such as Y2Y can enhance protected area growth and other conservation metrics. We conclude that large‐landscape conservation strategies may be a useful model for achieving global large‐landscape conservation and biodiversity conservation targets.

Recent events related to the measures taken to control the spread of the Coronavirus (SARS-CoV-2) reduced human mobility (i.e. anthropause), potentially opening connectivity opportunities for wildlife populations. In the Italian Alps, brown bears have recovered after reintroduction within a complex anthropogenic matrix, but failed to establish a metapopulation due to reduced connectivity and human disturbance (i.e. infrastructure, land use, and human mobility). Previous work from Peters et al. (2015, Biol. Cons. 186, 123–133) predicted the main corridors and suitable hot spots for road network crossing for this population across all major roads and settlement zones, to link most suitable habitats. Bears used the identified hot spots for road network crossing over the years, but major barriers such as main motor roads were not overcome, possibly due to functional anthropogenic disturbance, specifically human mobility. By analyzing 404 bear occurrences reported to local authorities (as bear-related complaints) collected between 2016 and 2020 (March 9th - May 18th), hence including the COVID-19 related lockdown, we tested the effect of human presence on brown bears' use of space and hot spots for road network crossing. Animals occupied human-dominated spaces and approached hot spots for crossing at a higher rate during the lockdown than in previous years, suggesting that connectivity temporarily increased with reduced human mobility for this population. As a result of their increased use of hot spots, bears expanded their use of suitable areas beyond the population core area. Movement of animals across structural barriers such as roads and human settlements may therefore occur in absence of active disturbance. We also showed the value of predictive models to identify hot spots for animal barrier crossing, the knowledge of which is critical when implementing management solutions to enhance connectivity. Understanding the factors that influence immigration and emigration across metapopulations of large mammals, particularly carnivores that may compete indirectly with humans for space or directly as super-predators, is critical to ensure the long-term viability of conservation efforts for their persistence. We argue that dynamic factors such as human mobility may play a larger role than previously recognized.

Abstract Habitat loss is often the ultimate cause of species endangerment and is also a leading factor inhibiting species recovery. For this reason, species‐at‐risk legislation, policies and plans typically focus on habitat conservation and restoration as mechanisms for recovery. To assess the effectiveness of these instruments in decelerating habitat loss, we evaluated spatiotemporal habitat changes for an iconic endangered species, woodland caribou (Rangifer tarandus caribou). We quantified changes in forest cover, a key proxy of caribou habitat, for all caribou subpopulations in Alberta and British Columbia, Canada. Despite efforts under federal and provincial recovery plans, and requirements listed under Canada's Species at Risk Act, caribou subpopulations lost twice as much habitat as they gained during a 12‐year period (2000–2012). Drivers of habitat loss varied by ecotype, with Boreal and Northern Mountain caribou affected most by forest fire and Southern Mountain caribou affected more by forest harvest. Our case study emphasizes critical gaps between recovery planning and habitat management actions, which are a core expectation under most species‐at‐risk legislation. Loss of caribou habitat from 2000 to 2018 has accelerated. Linear features within caribou ranges have also increased over time, particularly seismic lines within Boreal caribou ranges, and we estimated that only 5% of seismic lines have functionally regenerated. Our findings support the idea that short‐term recovery actions such as predator reductions and translocations will likely just delay caribou extinction in the absence of well‐considered habitat management. Given the magnitude of ongoing habitat change, it is clear that unless the cumulative impacts of land‐uses are effectively addressed through planning and management actions that consider anthropogenic and natural disturbances, we will fail to achieve self‐sustaining woodland caribou populations across much of North America.

Abstract Aim The influence of humans on large carnivores, including wolves, is a worldwide conservation concern. In addition, human‐caused changes in carnivore density and distribution might have impacts on prey and, indirectly, on vegetation. We therefore tested wolf responses to infrastructure related to natural resource development (i.e., human footprint). Location Our study provides one of the most extensive assessments of how predators like wolves select habitat in response to various degrees of footprint across boreal ecosystems encompassing over a million square kilometers of Canada. Methods We deployed GPS‐collars on 172 wolves, monitored movements and used a generalized functional response (GFR) model of resource selection. A functional response in habitat selection occurs when selection varies as a function of the availability of that habitat. GFRs can clarify how human‐induced habitat changes are influencing wildlife across large, diverse landscapes. Results Wolves displayed a functional response to footprint. Wolves were more likely to select forest harvest cutblocks in regions with higher cutblock density (i.e., a positive functional response to high‐quality habitats for ungulate prey) and to select for higher road density in regions where road density was high (i.e., a positive functional response to human‐created travel routes). Wolves were more likely to use cutblocks in habitats with low road densities, and more likely to use roads in habitats with low cutblock densities, except in winter when wolves were more likely to use roads regardless of cutblock density. Main conclusions These interactions suggest that wolves trade‐off among human‐impacted habitats, and adaptively switch from using roads to facilitate movement (while also risking encounters with humans), to using cutblocks that may have higher ungulate densities. We recommend that conservation managers consider the contextual and interacting effects of footprints when assessing impacts on carnivores. These effects likely have indirect impacts on ecosystems too, including on prey species.

The historical turn in the social sciences has been neglected by historians. This has caused social scientists to use much data which has not been curated by experts focused on the relevant time periods and geographic locations. A recent article by Oka et al. investigating the important question of historical trends in violence is a good example. A detailed survey of Oka et al.’s Persian, Greek and Roman population, army size and casualty data reveals several problems. The uncertainty in ancient data, especially casualty figures, has been underappreciated by Oka et al. In population and army size data, some speculative and dependent data points have been treated as independent. There are also inconsistencies in the data and some inflated figures. The situation is worse for the ancient army size and casualty figures for individual battles used by Oka et al., which suffer from systematic biases designed to magnify the achievements of the historian's own culture. This is clearly illustrated by the main battles of Alexander the Great against the Persians, in which Alexander's forces, although greatly outnumbered, are supposed to have inflicted hundreds or thousands of times more casualties that they sustained. These issues demonstrate the importance of curation of such data by scholars focused on the relevant time periods and cultures, and we recommend that historians become actively involved in such research.

Abstract Population monitoring can take many different forms, and monitoring elusive and endangered species frequently involves a variety of sparse data from different sources. Small populations are often hard to sample precisely and without bias, so when estimates of vital rates like survival or recruitment point to conflicting population trends, it can be hard to determine which is more correct. Furthermore, data can be extremely hard to collect on small populations and it can be helpful to find a way to use all available hard‐won data. To address these issues, we developed an integrated population model (IPM) using all available data to estimate vital rates and abundance for a case study of an endangered woodland caribou (Rangifer tarandus caribou) population. This IPM allowed us to incorporate data from juvenile recruitment surveys, telemetry‐based survival, aerial population counts and mark–resight data, and non‐invasive capture–recapture DNA data to better understand population status and trend. We estimated survival, abundance, and recruitment of four age classes of male and female caribou: young, juveniles, subadults, and adults. The four‐age class structure of the IPM allowed us to estimate recruitment from reproductive‐aged female caribou alone, even though it can be difficult to distinguish age classes—and even sexes—in the field. As part of our IPM, we developed a novel mixture model to break apart data from different age classes when age is unobservable, as it typically is from non‐invasive DNA samples. This helped us decrease bias in juvenile and adult survival estimates from scat data, which was important to our understanding of the population dynamics. Overall, our integrated model provided more precise estimates of population trends than any one method (e.g., telemetry or non‐invasive DNA) alone. This IPM provides a useful, flexible tool for biologists to monitor populations and provides a valuable example of the benefits of integrated population modeling approaches for endangered species management and recovery.

Abstract 1. Endangered species policies and their associated recovery documents and management actions do not always sufficiently address the importance of migratory behaviour and seasonal ranges for imperilled populations. 2. Using a telemetry location dataset spanning 1981–2018, we tested for changes in prevalence of migratory tactics (resident, migrant) over time, switching between tactics, shifts in seasonal space use including migration corridors, and survival consequences of migrant and resident tactics for 237 adult female endangered woodland mountain caribou in one population in western Canada. 3. Over more than three decades, the proportion of individuals displaying annual migration to the low elevation forested winter range declined from nearly 100%–38%. Correspondingly, there was a strong switch away from being migrant to being year‐round residents at high elevation. 4. These behavioural changes corresponded to abandonment of low elevation winter ranges in association with increasing levels of anthropogenic land uses, including forestry and oil and gas developments. Furthermore, there were no identifiable migration corridors to target for migratory route protection. 5. These shifts translated to lower survival rates, particularly for caribou demonstrating resident tactics, consistent with recent declines of the caribou population. That migrants switched to residency in their largely undisturbed summer range, despite lower survival, indicates maladaptive habitat selection consistent with recent patterns of mountain caribou extirpations. 6. Globally, endangered species policies and their associated recovery plans and management actions often do not explicitly consider the challenge of protecting migratory species. Effective conservation of migratory species requires protecting critical habitats needed for the entire life history of the species, including all seasonal ranges and migratory habitat.

Large carnivores are important ecological drivers of ecosystem dynamics when they occur at ecologically effective densities. They are also challenging to conserve, especially in transboundary settings such as along borders of parks and protected areas. Here, we tested for effects of transboundary movements on survival of 72 radiocollared gray wolves from 1987 to 2018 in and adjacent to Banff National Park, Canada. We fit Bayesian counting-process survival models to known-fate radiotelemetry data and tested for the influence of intrinsic covariates such as sex and age, time, and movements outside of protected areas on survival of wolves. We also estimated cause-specific mortality. Non-parametric survival was 0.733 (95% CI 0.622–0.816), and the top Bayesian survival model indicated that wolves outside the park had much lower annual survival rates (0.44, 95% BCI = 0.24–0.65) compared to wolves inside the park (0.84, 95% BCI = 0.73–0.91). The cumulative risk of mortality was on average 6.7 times higher (odds ratio 95% BCI = 2.2–21.4) for wolves outside the park, peaking during the winter hunting and trapping seasons. We found weak evidence for declining survival over time, opposite to patterns predicted by density-dependence. Bayesian cause-specific mortality indicated that the top three sources of mortality were trapping (rate = 0.080, 36% of mortality), followed by hunting (0.053, 18%), and highway (0.046, 18%) mortality. Surprisingly, we found no intraspecific mortality, and low dispersal from Banff National Park. This demographic profile is akin to other exploited populations across North America. While we were unable to combine survival rates with reproduction to estimate population trends, the overall mortality rates within our study area are consistent with a stable wolf population. Nonetheless, the long-term stability and ecological effectiveness of wolves likely differed inside and outside of protected areas, which highlights a challenge with managing transboundary carnivores exposed to different management regimes.

Many large herbivore populations are partially migratory, in which the population is comprised of both non-migratory (resident) and migratory individuals. Density-dependence contributes to regulating the dynamics of partially migratory populations by altering habitat selection, vital rates, or rates of behavioral switching between migratory tactics. Studies of mechanisms leading to these shifts have focused mainly on their behavior on summer range, overlooking the potential for density-dependent effects during winter that may influence decisions to migrate. We hypothesized that competition for food and safety from wolf predation risk on winter ranges would differentially affect habitat selection, movements, and grouping behavior of migrant and resident female North American elk (Cervus canadensis) on their sympatric winter range. We used GPS locations from 92 adult female elk in 155 elk-winters at Ya Ha Tinda, Alberta, Canada, over a 14-year period when the elk population declined by ∼70% to test our hypotheses. Elk showed consistently strong selection for areas of high forage biomass that corresponded to longer residence times and shorter return times to areas of high forage biomass. The strength of the selection diminished at high elk population size as did the extent to which elk traded off forage for safety from wolf predation risk. Elk increased movement rates and extended return times only to the riskiest areas. Median group size and mean sociality among elk increased at low population size, with resident elk groups being larger and more cohesive than migrant groups. Similar density-dependent responses by migrant and resident female elk on sympatric winter range indicate resident elk do not alter foraging behaviors to compensate for exposure to low nutritional resources in summer, implicating seasonal differences in nutrition are not mediated by winter densities in this system. We discuss the implications of competition on winter ranges for the maintenance of partial migration in ungulates in montane systems.

Abstract Identifying habitat that is essential to the recovery of species at risk, known as critical habitat, is a major focus of species at risk legislation, yet there has been little research on the degree to which these areas are protected. Here, we first review the provisions for protecting critical habitat on non‐federal lands within Canada's Species at Risk Act (SARA). Next, we use the declining southern mountain population of woodland caribou (Rangifer tarandus caribou) in British Columbia, Canada as a case study to show that identification of critical habitat does not guarantee its protection on non‐federal lands. Our analyses show that 909 km2 of critical habitat identified on provincial lands were logged in 5 years after it was legally identified under SARA. Existing provincial legislation and policies have provided incomplete protection of caribou critical habitat, and Canada's federal government has yet to exercise authority under SARA that could protect these areas. In the absence of nondiscretionary protection under provincial legislation, a combination of alternative mechanisms, involving all levels of government, Indigenous people, and industry, will be essential to protect critical habitat and help recover species at risk.

Abstract Imperfect detection is ubiquitous among wildlife research and is therefore commonly included in abundance estimation. Yet, the factors that affect observation success are largely unknown for rare and elusive species, such as large carnivores. Here, we took advantage of intensive ground‐based monitoring effort and an extensive GPS data set (2000–2018) and developed a winter sightability model for gray wolves (Canis lupus) in northern Yellowstone National Park, Wyoming, USA. Our resulting sightability model indicated that observation success was positively affected by the topographic nature of where wolves were in relation to observer locations (viewshed), areas being less forested (openness), and wolf group size, and negatively affected by distance from observer locations. Of these, viewshed had the strongest effect on the probability of observing a wolf, with the odds of observing a wolf being four times more likely when wolves were in the predicted viewshed. Openness was the next most influential covariate, and group size was the least influential. We also tested whether a wolf being harvested from a pack when they were outside of Yellowstone National Park had an effect on wolf sightability. We did not, however, find support for human‐induced mortality affecting wolf sightability inside of Yellowstone National Park. Our results indicate that the ability to observe wolves was greatly affected by ecological and landscape‐level factors, a finding that is likely to generally extend to other large carnivores. As such, our sightability model highlights the importance of considering landscape structure and variation in large carnivore use of the landscape when conducting observational‐based studies.

A significant challenge of conservation biology is to preserve species in places where their critical habitat also attracts significant economic interest. The problem is compounded when species distributions occur across large spatial extents. Threatened boreal caribou (Rangifer tarandus caribou) epitomize this problem: their critical habitat encompasses a vast expanse of forest that also supplies much of Canada's merchantable timber. Boreal caribou were protected under the Canada Species at Risk Act in 2003. We investigated putative drivers of reduced disturbance for caribou habitat since then. Where the cumulative logging footprint slowed within caribou habitat, this has resulted neither from decreases in annual allowable cut of timber nor the creation or expansion of protected areas. Rather, it has fluctuated with the American economy relative to that of Canada. For each $0.05 US lost over the $CAD, 129 km2 of caribou habitat was not disturbed by logging in a given year. Recent population declines have been occurring even though logging typically remained at

We studied the habitat selection of pronghorn (Antilocapra americana) during seasonal migration; an important period in an animal's annual cycle associated with broad-scale movements. We further decompose our understanding of migration habitat itself as the product of both broad- and fine-scale behavioral decisions and take a multi-scale approach to assess pronghorn spring and fall migration across the transboundary Northern Sagebrush Steppe region. We used a hierarchical habitat selection framework to assess a suite of natural and anthropogenic features that have been shown to influence selection patterns of pronghorn at both broad (migratory neighborhood) and fine (migratory pathway) scales. We then combined single-scale predictions into a scale-integrated step selection function (ISSF) map to assess its effectiveness in predicting migration route habitat. During spring, pronghorn selected for native grasslands, areas of high forage productivity (NDVI), and avoided human activity (i.e., roads and oil and natural gas wells). During fall, pronghorn selected for native grasslands, larger streams and rivers, and avoided roads. We detected avoidance of paved roads, unpaved roads, and wells at broad spatial scales, but no response to these features at fine scales. In other words, migratory pronghorn responded more strongly to anthropogenic features when selecting a broad neighborhood through which to migrate than when selecting individual steps along their migratory pathway. Our results demonstrate that scales of migratory route selection are hierarchically nested within each other from broader (second-order) to finer scales (third-order). In addition, we found other variables during particular migratory periods (i.e., native grasslands in spring) were selected for across scales indicating their importance for pronghorn. The mapping of ungulate migration habitat is a topic of high conservation relevance. In some applications, corridors are mapped according to telemetry location data from a sample of animals, with the assumption that the sample adequately represents habitat for the entire population. Our use of multi-scale modelling to predict resource selection during migration shows promise and may offer another relevant alternative for use in future conservation planning and land management decisions where telemetry-based sampling is unavailable or incomplete.

Wildlife-vehicle collisions imperil humans, wildlife, and property. Collisions with moose (Alces alces ) are especially consequential and there are indications they may increase during severe winters. We tested hypotheses regarding the influence of moose movements and vehicular traffic patterns on collision risk. We first modeled daily snow depth and accumulation across 5.6 million km ^2 of the North American Arctic-Boreal region. Next, we analyzed the movements and road use of 113 GPS-collared moose in response to snow depth. Finally, we examined the influence of these snow properties on vehicular traffic and 7680 moose-vehicle collisions. As winter progressed and the snowpack deepened in each study area, GPS-collared moose migrated to lower elevations, leading them into areas with shallower snow but higher road densities. This elevational migration corresponded with a higher probability of road-use by moose (by up to ten-fold) in winter than in summer. Corresponding to these patterns, moose-vehicle collisions were 2.4–5.7 times more frequent from December through February (compared to early summer). Collision risk was highest when and where snow depth was less than 120 cm, indicating that migration into areas with shallower snow increased collision risk in those areas. Most (82%) moose-vehicle collisions occurred after dark. This pattern was strongest during winter, when nighttime traffic volumes were eight times higher than summer due to longer nights. Overall, our findings suggest that concurrent seasonal changes in human and wildlife behavior increase the frequency of moose-vehicle collisions during winter. Snow depth influences collisions primarily through its impacts on moose movement, while strong seasonal changes in daylight hours cause an increase in nighttime traffic that further contributes to risk. This information may help predict times and places where risk of moose-vehicle collisions are highest and to develop seasonally dynamic mitigation strategies.

Abstract The Arctic has been warming rapidly, affecting ecological processes across the region. Caribou and reindeer (Rangifer tarandus) is a keystone Arctic species undergoing declines in many parts of its range, but definitive links between climate and populations remain elusive. The conspicuous and dramatic mass migration of many caribou populations, during which nearly all pregnant females move from wintering ranges to calving grounds shortly before giving birth, may be an important link between climate and caribou populations. The drivers of migration, however, are similarly mysterious. It is unknown, for example, whether caribou respond to immediate phenological cues, anticipate conditions on calving grounds, or are driven by lagged effects related to physical condition. To investigate the drivers of migration, we analyzed movement data from over 1000 individual caribou from seven major herds, spanning 3000 km across Alaska, Yukon, Northwest Territories (NWT), and Nunavut in Canada, from 1995 to 2017. We developed a hierarchical model to estimate migration departure and arrival times, and analyzed these variables against global climate indices and local weather conditions, exploring immediate and lagged effects, as well as snowmelt timing and vegetation indices. We discovered a continent‐wide synchrony in spring migration departure times, driven mainly by large‐scale, ocean‐driven climate indices (Pacific Decadal Oscillation, Arctic Oscillation, and North Atlantic Oscillation). However, we also found that the speed of migration was highly plastic with later migration departure times followed by shorter migration durations. This plasticity made arrival timing independent of departure timing and its respective drivers. Rather, arrival timing depended strongly on weather conditions from the previous summer: cooler and windier summers generally led to earlier arrival at calving grounds the following year. We suggest that maternal body condition, mainly influenced by conditions that limit insect harassment, is a major factor for earlier spring migration arrival timing, and therefore earlier calving and higher survival rates. We place these results in the context of mechanistic links between climate and caribou population dynamics. Long‐term and large‐scale observations of migratory animals can provide insights into the mechanisms by which long‐distance, collective migrants may adapt to dynamic and unpredictable environments.

Abstract Winter recreation is a widely popular activity and is expected to increase due to changes in recreation technology and human population growth. Wildlife are frequently negatively impacted by winter recreation, however, through displacement from habitat, alteration of activity patterns, or changes in movement behavior. We studied impacts of dispersed and developed winter recreation on Canada lynx (Lynx canadensis) at their southwestern range periphery in Colorado, USA. We used GPS collars to track movements of 18 adult lynx over 4 years, coupled with GPS devices that logged 2,839 unique recreation tracks to provide a detailed spatial estimate of recreation intensity. We assessed changes in lynx spatial and temporal patterns in response to motorized and nonmotorized recreation, as well as differences in movement rate and path tortuosity. We found that lynx decreased their movement rate in areas with high‐intensity back‐country skiing and snowmobiling, and adjusted their temporal patterns so that they were more active at night in areas with high‐intensity recreation. We did not find consistent evidence of spatial avoidance of recreation: lynx exhibited some avoidance of areas with motorized recreation, but selected areas in close proximity to nonmotorized recreation trails. Lynx appeared to avoid high‐intensity developed ski resorts, however, especially when recreation was most intense. We conclude that lynx in our study areas did not exhibit strong negative responses to dispersed recreation, but instead altered their behavior and temporal patterns in a nuanced response to recreation, perhaps to decrease direct interactions with recreationists. However, based on observed avoidance of developed recreation, there may be a threshold of human disturbance above which lynx cannot coexist with winter recreation.

Abstract Outdoor recreationists are important advocates for wildlife on public lands. However, balancing potential impacts associated with increased human disturbance with the conservation of sensitive species is a central issue facing ecologists and land managers alike, especially for dispersed winter recreation due to its disproportionate impact to wildlife. We studied how dispersed winter recreation (outside developed ski areas) impacted a reintroduced meso‐carnivore, Canada lynx (Lynx canadensis), at the southern periphery of the species’ range in the southern Rocky Mountains. On a voluntary basis, we distributed global positioning system (GPS) units to winter recreationists and documented 2143 spatial movement tracks of recreationists engaged in motorized and nonmotorized winter sports for a total cumulative distance of 56,000 km from 2010 to 2013. We also deployed GPS radio collars on adult Canada lynx that were resident in the mountainous topography that attracted high levels of dispersed winter recreation. We documented that resource‐selection models (RSFs) for Canada lynx were significantly improved when selection patterns of winter recreationists were included in best‐performing models. Canada lynx and winter recreationists partitioned environmental gradients in ways that reduced the potential for recreation‐related disturbance. Although the inclusion of recreation improved the RSF model for Canada lynx, environmental covariates explained most variation in resource use. The environmental gradients that most separated areas selected by Canada lynx from those used by recreationists were forest canopy closure, road density, and slope. Canada lynx also exhibited a functional response of increased avoidance of areas selected by motorized winter recreationists (snowmobiling off‐trail, hybrid snowmobile) compared with either no functional response (hybrid ski) or selection for (backcountry skiing) areas suitable for nonmotorized winter recreation. We conclude with a discussion of implications associated with providing winter recreation balanced with the conservation of Canada lynx.

Partial migration, a phenomenon wherein only some individuals within a population migrate, is taxonomically widespread. While well-studied in birds and fish, partial migration in large herbivores has come into the spotlight only recently due to the decline of migratory behavior in ungulate species around the world. We explored whether partial migration in ungulates is maintained at the population level through frequency-dependence, an environmental-genetic threshold, or a conditional strategy. Through a review of studies describing individual variation in migratory behavior, we then addressed how density-dependent and -independent factors such as social constraints, competition for forage, and escape from predators or pathogens, alone or together, could lead to occurrence of both migrants and residents within a population. We searched for evidence that intrinsic and extrinsic factors could combine with genetic predispositions and individual differences in temperament or life experience to promote migratory tendencies of individuals. Despite the long-held assumption for ungulates that migration is a fixed behavior of individuals, evidence suggested that flexibility in migratory behavior is more common than previously thought. Partial migration maintained by a conditional strategy results in changes in movement tactics as state-dependent responses of individuals. Data are needed to empirically demonstrate which factors determine the relative costs and benefits to using migratory vs. resident tactics. We outline what types of long-term data could address this need and urge those studying migration to meet these challenges in the interest of conserving partially migratory populations.

Abstract Few studies have examined differential responses of partially migratory ungulates to human development or activity, where some individuals in a population migrate and others do not. Yet understanding how animals with different movement tactics respond to anthropogenic disturbance is key to sustaining global ungulate migrations. We examined seasonal resource selection of a partially migratory population of pronghorn (Antilocapra americana) in the Northern Sagebrush Steppe of Alberta, Saskatchewan, and Montana from 2003 to 2011. We developed step‐selection functions (SSF) for migrant and resident pronghorn during the summer and winter at two spatial scales (second order and third order) and then integrated SSFs across scales to estimate pronghorn responses to fences and subsequent habitat loss from these features while accounting for responses to other resource use. Both migrant and resident pronghorn showed the strongest responses to natural and anthropogenic features at the second order and weaker responses at the third order. Selection responses of migrant and residents differed the most in response to normalized difference vegetation index, topography, and anthropogenic features. Seasonally, selection for intermediate greenness was strongest in summer, whereas avoidance of roads strongly influenced winter resource selection of both tactics. Both migrant and resident pronghorn showed strong avoidance of fencing at both spatial scales during summer and winter. Model predictions with complete removal of fences from the landscape (i.e., natural conditions) predicted an increase in the area of high‐quality habitat of 16–38%. In contrast, doubling fence density on the landscape decreased the amount of high‐quality habitat by 1–11% and increased low‐quality habitat by 13–21%. Our results suggest that pronghorn winter and summer ranges can be improved by reducing the density of fences on the landscape, or mitigation measures to enhance fence crossings, to alleviate the indirect loss of habitat for this important endemic prairie species.

Arctic and boreal ecosystems are experiencing rapid changes in temperature and precipitation regimes. Subsequent shifts in seasonality can lead to a mismatch between the timing of resource availability and species’ life-history events, known as phenological or trophic mismatch. Although mismatch has been shown to negatively affect some northern animal populations, longer-term impacts across large regions remain unknown. In addition, animals may rely on climate cues during preceding seasons to time key life history events such as reproduction, but the reliability of these cues as indicators of subsequent resource availability has not been examined. We used remote sensing and gridded spatial data to evaluate the effect of climate factors on the reproductive phenology and success of a wide-ranging carnivore, the gray wolf ( Canis lupus ). We used global positioning system (GPS) location data from 388 wolves to estimate den initiation dates ( n = 227 dens within 106 packs) and reproductive success in eight populations across northwestern North America from 2000 to 2017. Spring onset shifted 14.2 d earlier, on average, during the 18-year period, but the regional mean date of denning did not change. Preceding winter temperature was the strongest climatic predictor of denning phenology, with higher temperatures advancing the timing of denning. Winter temperature was also one the strongest and most reliable indicators of the timing of spring onset. Reproductive success was not affected by timing of denning or synchrony with spring onset, but improved during cooler summers and following relatively dry autumns. Our findings highlight a disconnect between climate factors that affect phenology and those that affect demography, suggesting that carnivores may be resilient to shifts in seasonality and yet sensitive to weather conditions affecting their prey at both local and regional scales. These insights regarding the relationship between climate and carnivore demography should improve predictions of climate warming effects on the highest trophic levels.

Previous research indicates that the effects of climate warming, including shrub expansion and increased fire frequency may lead to declining lichen abundance in arctic tundra and northern alpine areas. Lichens are important forage for caribou ( Rangifer tarandus ), whose populations are declining throughout most of North America. To clarify how lichen cover might affect caribou resource selection, ecologists require better data on the spatial distribution and abundance of lichen. Here, we use a combination of field data and satellite imagery to model lichen cover for a 583 200 km ^2 area that fully encompasses nine caribou ranges in interior Alaska and Yukon. We aggregated data from in situ vegetation plots, aerial survey polygons and unmanned aerial vehicle (UAV) imagery to align with 30 m resolution Landsat pixels. We used these data to train a random forest model with a suite of environmental and spectral predictors to estimate lichen cover. We validated our lichen cover model using reserved training data and existing external datasets, and found that reserved data from aerial survey polygons ( R ^2 = 0.77) and UAV imagery ( R ^2 = 0.71) provided the best fit. We used our lichen cover map to evaluate the influence of estimated lichen cover on caribou resource selection in the Fortymile Herd from 2012 to 2018 during summer and winter. In both seasons, caribou avoided lichen-poor areas (0%–5% lichen cover) and showed stronger selection as lichen cover increased to ∼30%, above which selection leveled off. Our results suggest that terrestrial lichen cover is an important factor influencing caribou resource selection in northern boreal forests across seasons. Our lichen cover map goes beyond existing maps of lichen abundance and distribution because it incorporates extensive field data for model training and validation and estimates lichen cover over a much larger spatial extent. We expect our landscape-scale map will be useful for understanding trends in lichen abundance and distribution, as well as for caribou research, management and conservation.

Migratory birds have the capacity to shift their migration phenology in response to climatic change. Yet the mechanistic underpinning of changes in migratory timing remain poorly understood. We employed newly developed global positioning system (GPS) tracking devices and long-term dataset of migration passage timing to investigate how behavioral responses to environmental conditions relate to phenological shifts in American robins ( Turdus migratorius ) during spring migration to Arctic-boreal breeding grounds. We found that over the past quarter-century (1994–2018), robins have migrated ca. 5 d/decade earlier. Based on GPS data collected for 55 robins over three springs (2016–2018), we found the arrival timing and likelihood of stopovers, and timing of arrival to breeding grounds, were strongly influenced by dynamics in snow conditions along migratory paths. These findings suggest plasticity in migratory behavior may be an important mechanism for how long-distance migrants adjust their breeding phenology to keep pace with advancement of spring on breeding grounds.

Across the boreal forest of Canada, habitat disturbance is the ultimate cause of caribou (Rangifer tarandus caribou) declines. Habitat restoration is a focus of caribou recovery efforts, with a goal to finding ways to reduce predator use of disturbances, and caribou-predator encounters. One of the most pervasive disturbances within caribou ranges in Alberta, Canada are seismic lines cleared for energy exploration. Seismic lines facilitate predator movement, and although vegetation on some seismic lines is regenerating, it remains unknown whether vegetation regrowth is sufficient to alter predator response. We used Light Detection and Ranging (LiDAR) data, and GPS locations, to understand how vegetation and other attributes of seismic lines influence movements of two predators, wolves (Canis lupus) and grizzly bears (Ursus arctos). During winter, wolves moved towards seismic lines regardless of vegetation height, while during spring wolves moved towards seismic lines with higher vegetation. During summer, wolves moved towards seismic lines with lower vegetation and also moved faster near seismic lines with vegetation

Snow covers Arctic and boreal regions (ABRs) for approximately 9 months of the year, thus snowscapes dominate the form and function of tundra and boreal ecosystems. In recent decades, Arctic warming has changed the snowcover’s spatial extent and distribution, as well as its seasonal timing and duration, while also altering the physical characteristics of the snowpack. Understanding the little studied effects of changing snowscapes on its wildlife communities is critical. The goal of this paper is to demonstrate the urgent need for, and suggest an approach for developing, an improved suite of temporally evolving, spatially distributed snow products to help understand how dynamics in snowscape properties impact wildlife, with a specific focus on Alaska and northwestern Canada. Via consideration of existing knowledge of wildlife-snow interactions, currently available snow products for focus region, and results of three case studies, we conclude that improving snow science in the ABR will be best achieved by focusing efforts on developing data-model fusion approaches to produce fit-for-purpose snow products that include, but are not limited to, wildlife ecology. The relative wealth of coordinated in situ measurements, airborne and satellite remote sensing data, and modeling tools being collected and developed as part of NASA’s Arctic Boreal Vulnerability Experiment and SnowEx campaigns, for example, provide a data rich environment for developing and testing new remote sensing algorithms and retrievals of snowscape properties.

Interest in bison (Bison bison, B. bonasus) conservation and restoration continues to grow globally. In Canada, plains bison (B. b. bison) are threatened, occupying less than 0.5% of their former range. The largest threat to their recovery is the lack of habitat in which they are considered compatible with current land uses. Fences and direct management make range expansion by most bison impossible. Reintroduction of bison into previously occupied areas that remain suitable, therefore, is critical for bison recovery in North America. Banff National Park is recognized as historical range of plains bison and has been identified as a potential site for reintroduction of a wild population. To evaluate habitat quality and assess if there is sufficient habitat for a breeding population, we developed a Habitat Suitability Index (HSI) model for the proposed reintroduction and surrounding areas in Banff National Park (Banff). We then synthesize previous studies on habitat relationships, forage availability, bison energetics and snowfall scenarios to estimate nutritional carrying capacity. Considering constraints on nutritional carrying capacity, the most realistic scenario that we evaluated resulted in an estimated maximum bison density of 0.48 bison/km2. This corresponds to sufficient habitat to support at least 600 to 1000 plains bison, which could be one of the largest 10 plains bison populations in North America. Within Banff, there is spatial variation in predicted bison habitat suitability and population size that suggests one potential reintroduction site as the most likely to be successful from a habitat perspective. The successful reintroduction of bison into Banff would represent a significant global step towards conserving this iconic species, and our approach provides a useful template for evaluating potential habitat for other endangered species reintroductions into their former range.

Digital cameras can provide a consistent view of vegetation phenology at fine spatial and temporal scales that are impractical to collect manually and are currently unobtainable by satellite and most aerial based sensors. This study links greenness indices derived from digital images in a network of rangeland and forested sites in Montana and Idaho to 16-day normalized difference vegetation index (NDVI) from NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS). Multiple digital cameras were placed along a transect at each site to increase the observational footprint and correlation with the coarser MODIS NDVI. Digital camera phenology indices were averaged across cameras on a site to derive phenological curves. The phenology curves, as well as green-up dates, and maximum growth dates, were highly correlated to the satellite derived MODIS composite NDVI 16-day data at homogeneous rangeland vegetation sites. Forested and mixed canopy sites had lower correlation and variable significance. This result suggests the use of MODIS NDVI in forested sites to evaluate understory phenology may not be suitable. This study demonstrates that data from digital camera networks with multiple cameras per site can be used to reliably estimate measures of vegetation phenology in rangelands and that those data are highly correlated to MODIS 16-day NDVI.

Many large carnivores occupy a wide geographic distribution, and face threats from habitat loss and fragmentation, poaching, prey depletion, and human wildlife-conflicts. Conservation requires robust techniques for estimating population densities and trends, but the elusive nature and low densities of many large carnivores make them difficult to detect. Spatial capture-recapture (SCR) models provide a means for handling imperfect detectability, while linking population estimates to individual movement patterns to provide more accurate estimates than standard approaches. Within this framework, we investigate the effect of different sample interval lengths on density estimates, using simulations and a common leopard (Panthera pardus) model system. We apply Bayesian SCR methods to 89 simulated datasets and camera-trapping data from 22 leopards captured 82 times during winter 2010-2011 in Royal Manas National Park, Bhutan. We show that sample interval length from daily, weekly, monthly or quarterly periods did not appreciably affect median abundance or density, but did influence precision. We observed the largest gains in precision when moving from quarterly to shorter intervals. We therefore recommend daily sampling intervals for monitoring rare or elusive species where practicable, but note that monthly or quarterly sample periods can have similar informative value. We further develop a novel application of Bayes factors to select models where multiple ecological factors are integrated into density estimation. Our simulations demonstrate that these methods can help identify the "true" explanatory mechanisms underlying the data. Using this method, we found strong evidence for sex-specific movement distributions in leopards, suggesting that sexual patterns of space-use influence density. This model estimated a density of 10.0 leopards/100 km2 (95% credibility interval: 6.25-15.93), comparable to contemporary estimates in Asia. These SCR methods provide a guide to monitor and observe the effect of management interventions on leopards and other species of conservation interest.

Refugia can affect predator-prey dynamics via movements between refuge and non-refuge areas. We examine the influence of a refuge on population dynamics in a large mammal predator-prey system. Wolves (Canis lupus) have recolonized much of their former range in North America, and as a result, ungulate prey have exploited refugia to reduce predation risk with unknown impacts on wolf-prey dynamics. We examined the influence of a refuge on elk (Cervus elaphus) and wolf population dynamics in Banff National Park. Elk occupy the Banff townsite with little predation, whereas elk in the adjoining Bow Valley experience higher wolf predation. The Banff refuge may influence Bow Valley predator-prey dynamics through source-sink movements. To test this hypothesis, we used 26 years of wolf and elk population counts and the Delayed Rejection Adaptive Metropolis Markov chain Monte Carlo method to fit five predator-prey models: 1) with no source-sink movements, 2) with elk density-dependent dispersal from the refuge to the non-refuge, 3) with elk predation risk avoidance movements from the non-refuge to the refuge, 4) with differential movement rates between refuge and non-refuge, and 5) with short-term, source-sink wolf movements. Model 1 provided the best fit of the data, as measured by Akaike Information Criterion (AIC). In the top model, Banff and Bow Valley elk had median growth rates of 0.08 and 0.03 (95% credibility intervals [CIs]: 0.027-0.186 and 0.001-0.143), respectively, Banff had a median carrying capacity of 630 elk (95% CI: 471.9-2676.9), Bow Valley elk had a median wolf encounter rate of 0.02 (95% CI: 0.013-0.030), and wolves had a median death rate of 0.23 (95% CI: 0.146-0.335) and a median conversion efficiency of 0.07 (95% CI: 0.031-0.124). We found little evidence for potential source-sink movements influencing the predator-prey dynamics of this system. This result suggests that the refuge was isolated from the non-refuge.

Ongoing debate about whether food webs are primarily regulated by predators or by primary plant productivity, cast as top-down and bottom-up effects, respectively, may becoming superfluous. Given that most of the world's ecosystems are human dominated we broadened this dichotomy by considering human effects in a terrestrial food-web. We studied a multiple human-use landscape in southwest Alberta, Canada, as opposed to protected areas where previous terrestrial food-web studies have been conducted. We used structural equation models (SEMs) to assess the strength and direction of relationships between the density and distribution of: (1) humans, measured using a density index; (2) wolves (Canis lupus), elk (Cervus elapahus) and domestic cattle (Bos taurus), measured using resource selection functions, and; (3) forage quality, quantity and utilization (measured at vegetation sampling plots). Relationships were evaluated by taking advantage of temporal and spatial variation in human density, including day versus night, and two landscapes with the highest and lowest human density in the study area. Here we show that forage-mediated effects of humans had primacy over predator-mediated effects in the food web. In our parsimonious SEM, occurrence of humans was most correlated with occurrence of forage (β = 0.637, p

Fire management is an important conservation tool in Canada’s national parks. Fires can benefit some species, while others may be negatively impacted. We used GPS and VHF collar data for 47 wolves from 12 separate packs and 153 caribou from 5 separate herds, and resource selection analysis to model the effects of fire on these species’ habitat and potential interactions. Resource selection modeling showed that wolves select for burned areas and areas close to burns, presumably due to the presence of primary prey (i.e., elk and moose), while caribou avoid burns. Fire reduced the amount of high quality caribou habitat (a direct effect), but also increased the probability of wolf-caribou overlap (an indirect effect). We delineated a spatial index of caribou “safe zones” (areas of low overlap with wolves), and found a positive relationship between the proportion of a herd’s home range represented by “safe zone” in winter and population size (P = 0.10, n=4). While currently-planned prescribed fires in Banff and Jasper reduced the amount of quality caribou habitat by up to 4%, they reduced the area of “safe zones” by up to 7%, varying by herd, location, and season. We suggest that conservation managers should account for the indirect, predator-mediated impacts of fire on caribou in addition to direct effects of habitat loss.

Woodland caribou populations are considered threatened in Alberta and have declined in the Canadian Rocky Mountain National Parks of Banff and Jasper despite protection from factors causing caribou populations to decline outside of parks. Recent research emphasizes the importance of the numeric response of wolves to moose in moose-caribou-wolf systems to caribou persistence. Moose are rare in the Canadian Rockies, where the dominant ungulate prey for wolves is elk. Few studies have explored wolf-elk dynamics and none have examined implications for caribou. We used data collected in Banff to estimate the numeric response of wolves to elk from 1985 to 2005. Because no caribou kill-rate data exist for the Rockies, we explore the consequences of a range of hypothetical kill-rates based on kill-rates of alternate prey collected from 1985 to 2000 in Banff. We then multiplied the numeric response of wolves by the estimated caribou kill-rates to estimate the wolf predation response on caribou as a function of elk density. Caribou predation rates were inversely density dependent because wolf numbers depend on prey species besides caribou in multiple prey species systems. We then combined this simple wolf-elk-caribou model with observed demographic and population estimates for Banff and Jasper caribou from 2003-2004 and solved for the critical kill-rate thresholds above which caribou populations would decline. Using these critical kill-rate thresholds, Jasper caribou are likely to persist when wolf densities are below 2.1 - 4.3 wolves/1000km2 and/or when elk densities are below 0.015- 0.033 elk/km2. Thresholds for Banff caribou persistence are much lower because of inverse density dependence. Future research is needed on some of the necessary assumptions underlying our modeling including multi-prey wolf numeric responses, wolf kill-rates of caribou, caribou mortality by other predators, and spatial aspects of wolf-elk-caribou dynamics.

National parks are important for conservation of species such as wolves (Canis lupus) and elk (Cervus canadensis). However, topography, vegetation conditions, and anthropogenic infrastructure within parks may limit available habitat. Human activity on trails and roads may lead to indirect habitat loss, further limiting available habitat. Predators and prey may respond differentially to human activity, potentially disrupting ecological processes. However, research on such impacts to wildlife is incomplete, especially at fine spatial and temporal scales. Our research investigated the relationship between wolf and elk distribution and human activity using fine-scale Global Positioning System (GPS) wildlife telemetry locations and hourly human activity measures on trails and roads in Banff, Kootenay, and Yoho National Parks, Canada. We observed a complex interaction between the distance animals were located from trails and human activity level resulting in species adopting both mutual avoidance and differential response behaviors. In areas < 50 m from trails human activity led to a mutual avoidance response by both wolves and elk. In areas 50 - 400 m from trails low levels of human activity led to differential responses; wolves avoided these areas, whereas elk appeared to use these areas as a predation refugia. These differential impacts on elk and wolves may have important implications for trophic dynamics. As human activity increased above two people/hour, areas 50 - 400 m from trails were mutually avoided by both species, resulting in the indirect loss of important montane habitat. If park managers are concerned with human impacts on wolves and elk, or on these species' trophic interactions with other species, they can monitor locations near trails and roads and consider hourly changes of human activity levels in areas important to wildlife.