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Globally, ungulate–vehicle collisions (UVCs) are a major human safety concern and may also represent a significant source of mortality for some ungulate populations. However, records of UVC based on counts of roadside carcasses or reports by drivers involved in these incidents are assuredly underestimated because not all ungulates struck die immediately or at the roadside or are reported by drivers or authorities. Here, we provide an observation and analysis of the movements of a GPS‐collared bison (Bison bison) that was involved in a UVC on the Alaska Highway and died in a thick boreal forest 29 days later. During that time, she moved 49.7 km from where she was hit. Her daily movement rate (in kilometers per hour) and daily net displacement (in kilometers per day) were significantly greater in the 29‐day period before she was struck compared with 29 days afterward. This vivid example illustrates that individuals injured in a UVC can die several weeks later and at a considerable distance from where they were initially struck. Moreover, when they eventually die, it may be where their carcass would not be found or associated with a UVC. Bison are the largest land mammal in North America and perhaps more robust to some lower impact UVC than smaller bodied species. Even so, if not for the GPS collar on this bison, we would have never known the fate of this individual, and the carcass likely never found. Taken together, the movements and final resting place of this bison illuminate how estimates of mortality as a result of UVC can be underestimated when the animal does not die immediately and in a location where it can be found. Given our data, we further urge managers to consider roadside counts of animals killed in UVC as a minimum estimate when considering options for mitigation. [ABSTRACT FROM AUTHOR]

Motion‐sensitive cameras are commonly used to monitor wildlife occupancy rates; however, few studies have assessed whether data from cameras are correlated with density estimates obtained from more traditional labor‐intensive methods such as those based on capture‐mark‐recapture. We used data from a boreal forest community to test whether camera data were correlated with densities estimated from independent monitoring methods. We placed 72 covert cameras in the forest around Lhù'ààn Mân' (Kluane Lake), Yukon, Canada, for 7 years and tracked changes in population densities by camera hit rates. We independently estimated population densities of snowshoe hares (Lepus americanus) and red squirrels (Tamiasciurus hudsonicus) using capture‐mark‐recapture via live trapping, and Canada lynx (Lynx canadensis), coyotes (Canis latrans), and moose (Alces americanus) by snow track transects. Density estimates obtained from conventional aerial surveys were also periodically available for moose. Except for red squirrels, camera hit rates were highly correlated with population density estimates obtained by traditional methods, including across a large range of estimated densities corresponding to cyclic population dynamics in several species. Accordingly, we infer that motion‐sensitive cameras could supplement or replace traditional methods for monitoring key species in boreal forest food webs. Using cameras to monitor population change has several advantages; they require less effort in the field, are non‐invasive compared to live‐trapping, include multiple species at the same time, and rely less on weather than either aerial surveys or snow track transects. Tracking changes across the vast boreal forest is becoming increasingly necessary because of climate and landscape change and our data validate the use of motion‐sensitive cameras to provide a useful quantitative method for state‐of‐the‐environment reporting. [ABSTRACT FROM AUTHOR]

Intraspecific interactions between mesocarnivores are not commonly observed and consequentially not well understood, particularly for species inhabiting wilderness regions. Using a remote camera, we captured interactions between a Canada lynx (Lynx canadensis) and wolverine (Gulo gulo) scavenging on the remains of a bison (Bison bison). Over a 23‐min period representing nine photographic sequences (1–3 photographs per sequence), we observed (1) a wolverine approach the remains that were being fed on by a lynx, (2) the two animals feeding on the remains at the same time for about 19 min, (3) the wolverine chasing the lynx off of the carcass and, thereafter, (4) the wolverine excluding the lynx from the carcass. Our observation is of potential scientific value because it sheds light on behavioral interactions between these two species, particularly at a rich food source. Intraguild interactions between these species appear to include tolerance toward one another, as well as interference competition, with the wolverine being the dominant species. Our observation highlights the new information on interactions between mesocarnivores that are becoming illuminated with the use of remote cameras, revealing that these interactions may be more complex than once thought. [ABSTRACT FROM AUTHOR]

The epidermis of wild mammals is occasionally lacerated or punctured and wound care behaviours evolved to keep animals healthy in nature. Communal wound licking may promote healing of affected sites, relieve stress after a traumatic experience, and reinforce social bonds among individuals. Yet, there are few reported cases of communal wound licking in free‐ranging mammals. We report observations of communal wound licking in a social ungulate—free‐ranging bison (Bison bison). Two adult female bison presented with minor open puncture wounds after we chemically immobilized each of them with a dart fired from a rifle. The day after being darted, we observed three different adult bison lick the wounds of the two wounded bison. Both bison were <3 m of each other during this time and all of the observed wound licking occurred in <10 min. Our observation provides an additional example of communal wound licking in free‐ranging mammals and extends it to a social ungulate. Benefits to bison of communal wound licking are perhaps largely social. However, targeted research is needed to better understand both the frequency and cost and benefits of communal wound licking. [ABSTRACT FROM AUTHOR]

Climate warming is causing asynchronies between animal phenology and environments. Mismatched traits, such as coat color change mismatched with snow, can decrease survival. However, coat change does not serve a singular adaptive benefit of camouflage, and alternate coat change functions may confer advantages that supersede mismatch costs. We found that mismatch reduced, rather than increased, autumn mortality risk of snowshoe hares in Yukon by 86.5% when mismatch occurred. We suggest that the increased coat insulation and lower metabolic rates of winter‐acclimatized hares confer energetic advantages to white mismatched hares that reduce their mortality risk. We found that white mismatched hares forage 17–77 min less per day than matched brown hares between 0°C and −10°C, thus lowering their predation risk and increasing survival. We found no effect of mismatch on spring mortality risk, during which mismatch occurred at warmer temperatures, suggesting a potential temperature limit at which the costs of conspicuousness outweigh energetic benefits. [ABSTRACT FROM AUTHOR]

Reduced food availability is implicated in declines in avian aerial insectivores, but the effect of nutritional stress on mammalian aerial insectivores is unclear. Unlike birds, insectivorous bats provision their young through lactation, which might protect nursing juveniles when prey availability is low but could increase the energetic burden on lactating females. We analyzed a 15‐year capture–mark–recapture data set from 5312 individual little brown myotis (Myotis lucifugus) captured at 11 maternity colonies in northwestern Canada, to test the hypothesis that nutritional stress is impacting these mammalian aerial insectivores. We used long‐bone (forearm [FA]) length as a proxy for relative access to nutrition during development, and body mass as a proxy for access to nutrition prior to capture. Average FA length and body mass both decreased significantly over the study period in adult females and juveniles, suggesting decreased access to nutrition. Effect sizes were very small, similar to those reported for declining body size in avian aerial insectivores. Declines in juvenile body mass were only observed in individuals captured in late summer when they were foraging independently, supporting our hypothesis that lactation provides some protection to nursing young during periods of nutritional stress. Potential drivers of the decline in bat size include one or both of (1) declining insect (prey) abundance, and (2) declining prey availability. Echolocating insectivorous bats cannot forage effectively during rainfall, which is increasing in our study area. The body mass of captured adult females and juveniles in our study was lower, on average, after periods of high rainfall, and higher after warmer‐than‐average periods. Finally, survival models revealed a positive association between FA length and survival, suggesting a fitness consequence to declines in body size. Our study area has not yet been impacted by bat white‐nose syndrome (WNS), but research elsewhere has suggested that fatter bats are more likely to survive infection. We found evidence for WNS‐independent shifts in the body size of little brown myotis, which can inform studies investigating population responses to WNS. More broadly, the cumulative effects of multiple stressors (e.g., disease, nutritional stress, climate change, and other pressures) on mammalian aerial insectivores require urgent attention. [ABSTRACT FROM AUTHOR]

Snowshoe hare cycles are one of the most prominent phenomena in ecology. Experimental studies point to predation as the dominant driving factor, but previous experiments combining food supplementation and predator removal produced unexplained multiplicative effects on density. We examined the potential interactive effects of food limitation and predation in causing hare cycles using an individual‐based food‐supplementation experiment over‐winter across three cycle phases that naturally varied in predation risk. Supplementation doubled over‐winter survival with the largest effects occurring in the late increase phase. Although the proximate cause of mortality was predation, supplemented hares significantly decreased foraging time and selected for conifer habitat, potentially reducing their predation risk. Supplemented hares also lost less body mass which resulted in the production of larger leverets. Our results establish a mechanistic link between how foraging time, mass loss and predation risk affect survival and reproduction, potentially driving demographic changes associated with hare cycles. [ABSTRACT FROM AUTHOR]

The boreal forest is the largest intact forest in the world, and a refuge for species experiencing range retractions as a consequence of climate and landscape change. Yet, large tracts of the boreal forest are threatened by the cumulative impacts of climate change, natural resource extraction, agriculture, and urbanization, perhaps warranting a shift in focus from biodiversity conservation in intact wilderness to that in anthropologically modified landscapes. We investigated landscape features that influence the distribution of the endangered little brown bat (Myotis lucifugus) in an urbanizing boreal landscape at two spatial scales. We hypothesized that little brown bat activity would be influenced by proximity to available building roosts, because roosts are a potential limiting factor for boreal bats. Secondarily, we predicted that bats would use potential foraging habitat, such as waterbodies, and would avoid young, cluttered forests at the landscape scale. We conducted acoustic surveys of bat activity at 210 sites distributed across the study area in Yukon, Canada, within 1‐km grid cells. We tested a priori hypotheses with a set of candidate regression models, accounting for spatial autocorrelation. Our hypothesis about the relative importance of anthropogenic roosts was not supported. Little brown bats were equally active in urban areas (high building density) and rural areas (low building density), perhaps because roosts were adequately available throughout the region. Instead, habitat use was driven by the distribution of potential foraging habitat, particularly waterbodies, which are important sources of aerial insect prey. Little brown bats also avoided young (≤100‐yr‐old) forest at the landscape scale (including areas regenerating after fire), which may have been poor foraging or roosting habitat, and used areas with a smaller agricultural and industrial footprint. Our results suggest that waterbodies and mature forest are important little brown bat habitats that should be protected from urban encroachment. Proactive conservation of important habitat for species at risk is still possible throughout much of the boreal forest, where human densities are comparatively low and the urban footprint is currently small. [ABSTRACT FROM AUTHOR]

We welcome Treves and Santiago-Ávila (2020) attention to important questions about human-wildlife conflicts (HWCs) and coexistence (Frank et al., 2019; König et al., 2020; Pooley et al., 2020) and their probing of scientific objectivity in conservation (Artelle et al., 2014; Clark, 2019; Shrader-Frechette, 1996; Wallington & Moore, 2005). We are sure that Treves and Santiago-Ávila did not intend to overlook the importance or legitimacy of Indigenous peoples' interests in conservation. Such teaching would promote sharing responsibility and ownership over decision-making and create space for underrepresented and vulnerable groups, future humans, and nonhuman species--a gap Treves and Santiago-Ávila identified. These regimes are germane counterexamples within Treves and Santiago-Ávila's analytical scope because they establish harvest quotas and routinely contend with HWCs (e.g., Clark et al., 2014, 2016; Dowsley & Wenzel, 2008). [Extracted from the article]

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Capture and handling of wildlife is often an important component of studies where detailed demographic, behavioral, physiological, or health data are required. Yet, capturing and handling wildlife is sometimes controversial and lacking public support because of concern about effects on individuals. Investigating potential effects of capturing wildlife is also important to inform data‐censoring protocols when using information obtained from captured animals. We investigated the short‐term effect of helicopter‐based capture and handling on movements of free‐ranging bison (Bison bison) that were chemically immobilized in Yukon, Canada. We examined daily movement rates, home range size, and displacement of global positioning system‐collared individuals immediately after capture and for 20 days thereafter. Our results indicate that there is a minimal short‐term effect of helicopter‐based capture on bison movements. Significant differences from apparent pre‐capture movement behavior were observed only within 24 hours after capture. We observed variation among individuals, however, with some animals taking up to 10 days to return to apparent pre‐capture movement rates, whereas others had no measurable response to capture. Despite individual variation, >80% of individuals had returned to apparent pre‐capture movement behavior within the first 5 days after capture. Furthermore, sex‐based effects were evident: females increased their daily movement rates, home range size, and displacement after capture, whereas males had either no effect or decreased movement rates. Our results suggest that movement rates are altered for only a short period after capture and, therefore, should not have severe negative effects on bison using our protocols. Accordingly, researchers should censor the first 10 days after capture from their analyses to avoid using biased information. Our study should also help inform public discourse regarding capturing and handling wildlife for research or management purposes. © 2019 The Wildlife Society Helicopter‐based capture of global positioning system (GPS)‐collared bison resulted in significant differences from pre‐capture movement behavior only within 24 hours after capture. We observed sex‐based differences in response to being captured and variation among individuals, with some animals taking up to 10 days to return to apparent pre‐capture movement rates. Accordingly, the first 10 days after capture should be censured from analyses to avoid using biased information. [ABSTRACT FROM AUTHOR]

Urban development is detrimental to many wildlife species; however, endangered little brown bats (Myotis lucifugus) may be attracted to human settlements, making them a synurbic species. Buildings likely provide high-quality roosting habitat, which may be a limiting factor in the boreal forest where trees are typically small and potentially unsuitable for hosting large maternity colonies. In the boreal forest, there are relatively few urban developments in a matrix of wilderness and apparently suboptimal natural roosting habitat; thus, we hypothesized that isolated rural villages were islands of summer habitat for little brown bats that may be important for their conservation and recovery. To test this hypothesis, we investigated the relationship between little brown bat activity, foraging rates, and proximity to rural villages. We expected bat activity and foraging rates to increase with proximity to villages, as bats should optimally forage near their roosts to minimize flight costs. We used ultrasonic detectors to passively monitor bat activity near three rural villages in Yukon, Canada, and characterized bat habitat with forest measurements and remotely sensed data. Bat activity increased with proximity to village centers, but foraging activity did not, suggesting that human settlements in the boreal forest were important as roosting rather than foraging habitat. Bat activity was higher near water bodies and areas with relatively high densities of linear features (e.g., roads and transmission lines), perhaps because prey were most abundant near water features and along forest edges. The island phenomenon we observed (i.e., higher bat activity near villages) has also been documented in larger human settlements at lower latitudes, where urban areas provided better roosting habitat than surrounding agricultural matrices. Given that little brown bats were concentrated near rural villages, small human settlements should be a focus of conservation efforts in the boreal forest--particularly the identification and protection of buildings used as maternity colonies. Our study advances knowledge of little brown bat habitat requirements in the boreal forest and identifies habitats that may be important for their recovery. [ABSTRACT FROM AUTHOR]

Abstract: Community and ecosystem changes are happening in the pristine boreal forest ecosystem of the Yukon for 2 reasons. First, climate change is affecting the abiotic environment (temperature, rainfall and growing season) and driving changes in plant productivity and predator–prey interactions. Second, simultaneously change is occurring because of mammal species reintroductions and rewilding. The key ecological question is the impact these faunal changes will have on trophic dynamics. Primary productivity in the boreal forest is increasing because of climatic warming, but plant species composition is unlikely to change significantly during the next 50–100 years. The 9–10‐year population cycle of snowshoe hares will persist but could be reduced in amplitude if winter weather increases predator hunting efficiency. Small rodents have increased in abundance because of increased vegetation growth. Arctic ground squirrels have disappeared from the forest because of increased predator hunting efficiency associated with shrub growth. Reintroductions have occurred for 2 reasons: human reintroductions of large ungulates and natural recolonization of mammals and birds extending their geographic ranges. The deliberate rewilding of wood bison (Bison bison) and elk (Cervus canadensis) has changed the trophic structure of this boreal ecosystem very little. The natural range expansion of mountain lions (Puma concolor), mule deer (Odocoileus hemionus) and American marten (Martes americana) should have few ecosystem effects. Understanding potential changes will require long‐term monitoring studies and experiments on a scale we rarely deem possible. Ecosystems affected by climate change, species reintroductions and human alteration of habitats cannot remain stable and changes will be critically dependent on food web interactions. [ABSTRACT FROM AUTHOR]

Aim We surveyed the genetic variability of deermice (genus Peromyscus) at the north-western edge of their range to test for occupancy in multiple, hypothesized ice-free regions during the late Pleistocene and explore post-glacial dynamics. Location North-western North America. Methods We used sequences from four independent nuclear and mitochondrial loci from 341 specimens of Peromyscus maniculatus, Peromyscus keeni and Peromyscus sp. (Yukon) to assess species limits, population structure, and demographical change as a result of historical climate change, using a Bayesian approach. Species distribution models were built in MaxEnt to explore the niche overlap amongst genetically distinct species. Results Divergence amongst three lineages began before the last interglacial, and each shows signs of post-glacial expansion. Multilocus species trees strongly support P. keeni and Peromyscus sp. (Yukon) as independent from P. maniculatus. Substantial substructure was observed for P. keeni across the fragmented Alexander Archipelago. Northern lineages or clades ( Peromyscus sp. and P. keeni) differed in potential ecological distributions. Main conclusions At the extreme north-western range of deermice in North America, three distinct lineages persist reflecting divergence in at least three ice-free regions [Beringia, Coastal (near Southeast Alaska) and Southern Continental] throughout the latest Pleistocene glacial cycles. Although spatially proximate in Yukon, no locations were identified where these lineages are in contact. Further, west along the Pacific Coast, P. keeni is widespread across the complex landscape of Southeast Alaska, yet there is limited contemporary gene flow amongst island populations, a finding consistent with the barriers produced by rising sea levels at the end of the Last Glacial Maximum. [ABSTRACT FROM AUTHOR]

ABSTRACT The potential for interspecific competition for food resources is a key consideration when newly introduced ungulates occupy a shared range with resident native species. Management plans in Yukon, Canada, for reintroduced bison ( Bison bison) and introduced elk ( Cervus canadensis) called for an assessment of competition for food resources between these species and resident populations of caribou ( Rangifer tarandus), thinhorn sheep ( Ovis dalli), and moose ( Alces americanus). To assess potential competition among ungulates, we examined dietary overlap of 7 ungulate species in southwestern Yukon, Canada. We compared diet composition at the forage class level and composite diet indices (diversity, evenness, and niche breadth) among species found at 2 elevation classes (high [≥1,200 m ASL] and low [<1,200 m ASL]) during summer and winter, using data derived from microhistological analyses of feces. Composite indices and percent of key forage classes in diets differed among ungulates during summer and winter and at both high and low elevations. Potential dietary overlap for most species pairs was low to moderate (0.07-0.60). However, for bison and thinhorn sheep at high elevations, and bison and semi-feral horses ( Equus ferus caballus) at low elevations, it was high (0.82-0.97) during both summer and winter, indicating potential for food competition. Dietary overlap between species appeared to be based primarily on morphophysiological classification (i.e., browser-intermediate-grazer), rather than body size. Bison, horses, and sheep were all grazers. Intermediate species, such as introduced elk, had only moderate dietary overlap with several species. We concluded that the potential for competition for food resources based on dietary overlap between bison and sheep and bison and horses may be high in our study area, depending on forage availability, but for all other species pairs in our study area the potential for forage competition is low to moderate. © 2015 The Wildlife Society. [ABSTRACT FROM AUTHOR]

Presents a study on habitat selection by forest bats in relation to mixed-wood stand types and structure in the forests of central Ontario. Quantification of structural characteristics in the stands sampled for bat activity; Habitat selection models; Response of bats to structural characteristics; Bat use of stand types; Bat species composition.