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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]

Surveillance of endoparasites at the host community level is rarely reported for ungulates. Yet, changes in the composition and abundance of species in ungulate assemblages, coupled with environmental and climate change, bring into focus the need for baseline data on endoparasite occurrence in host species at the community level. We investigated the prevalence and intensity of eggs of endoparasites in feces of a dynamic boreal ungulate community in Yukon, Canada, that included reintroduced bison (Bison bison), as well as introduced elk (Cervus canadensis), naturally colonizing mule deer (Odocoileus hemionus), and resident populations of caribou (Rangifer tarandus), moose (Alces americanus), and thinhorn sheep (Ovis dalli). We also examined the change in endoparasite prevalence and intensity in bison fecal samples collected eight years apart. The prevalence of eggs detected in feces differed across species for most endoparasite groups. We also provide new records of several endoparasites in novel hosts or new geographic records. We detected a substantially greater prevalence and intensity of trichostrongyle-type eggs in bison feces between samples collected eight years apart. Our data emphasize the need for targeted pathogen surveillance programs to monitor the movement of various ungulate and associated endoparasites. This is particularly pertinent since our data potentially supports evidence for the continued northward expansion and host switching of protostrongylid species, which may have health implications for animals at a new interface. [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]

While it is well documented that wolves (Canis lupus) hunt and scavenge bison (Bison bison) from some long-established populations, such ecological interactions are not well known for most small, reintroduced populations in the boreal forest. Indeed, predation or scavenging of reintroduced bison in the boreal forest is rarely reported. Yet, documenting instances of bison killed or consumed is imperative to understanding the integration of reintroduced populations into local food webs and ecosystems. Such observations also indicate that reintroduced bison may be under selective pressure from their key predator. We compiled 20 verifiable observations of wolves hunting or scavenging bison from three reintroduced populations in northwestern Canada. We report the first confirmed observations of wolves feeding on bison from the 'Nahanni' and 'Pink Mountain' populations. We also report new records of wolves hunting or scavenging bison from the 'Aishihik' population. Where sex was known, most (14 of 17) bison consumed were females and 17 of 20 were adults (either sex). Contrary to other studies, we found that 7 of 20 bison consumed by wolves were aged individuals. It took 19–50 years since bison were reintroduction before verifiable observations of wolf–bison interactions emerged for these populations, indicating that wolves were likely slow to view reintroduced bison as prey and incorporate them into their diets. These observations are of value mainly because they provide unequivocal evidence that these reintroduced bison populations are becoming integrated into local food webs and beginning to be under selective pressure by their main predator, both of which are hallmarks of ecological restoration. [ABSTRACT FROM AUTHOR]

Many mammals cross large rivers to access seasonal habitats, yet river crossing behavior is poorly acknowledged or understood. Crossing large rivers is inherently risky, with vessel traffic and flooding events increasing the risk of drowning. We investigated river crossing behavior by threatened bison (Bison bison) in the boreal forest, using data from 11 GPS-collared animals to identify when and where they cross a major river. We used kernel densities of GPS locations to identify crossing hotspots, and developed resource selection function (RSF) models that used habitat characteristics to explain crossing behavior based on a priori hypotheses. We then predicted high-probability crossing areas along a 400-km stretch of river using the best-supported RSF model. Bison regularly crossed the river (x̄ = 8.6 crossings/100 days), particularly during summer months. Model selection results suggested that bison may have chosen river crossing areas that maximized access to forage. Bison preferred to cross the river near islands and areas with high seismic line densities, both of which were likely preferred summer foraging habitats. In addition, islands may have been used as temporary stopovers while crossing the river, or for relief from biting insects. Bison crossed the river where the channel was relatively narrow (x̄ = 400 ± 213 m [SD]) and chose days when river discharge was low, likely to reduce the risk of drowning, exhaustion, or hypothermia. While based on a small sample of collared bison, predictions about high-probability crossing areas may be used to inform mitigation measures aimed at reducing bison drowning caused by vessel traffic, which is expected to increase as resource development expands in the region. Our approach may be informative for identifying river crossing hotspots for other mammals that cross major rivers. [ABSTRACT FROM AUTHOR]

Mapping habitat selection by threatened species provides critical information for conservation planning. For reintroduced populations, understanding habitat selection is also necessary to predict dispersal and inform selection of new reintroduction sites. Efforts to restore bison Bison bison to the boreal forest hinge on the persistence of geographically isolated populations that occupy diverse landscapes, and for many populations selected habitats are unknown. We used location data from GPS-collared bison to develop seasonal resource selection function (RSF) models and predictive maps for the reintroduced 'Nahanni' population. We accounted for variation in individual behaviour by calculating averaged population-level selection coefficients from individual RSFs, and we compared these results to a pooled RSF from all bison. Individual RSFs revealed variation in habitat selection that was not always captured by the pooled RSF, although there were some consistencies. Bison strongly selected forage-rich graminoid-dominated wetlands (fens) during winter, but less so in summer when there were potential tradeoffs with poor footing and biting flies. In summer, bison selected alternative sources of forage such as herbaceous, shrubby and fluvial habitats (i.e. riverine islands and gravel bars). The observed association with fluvial habitat may be an adaptation to low forage availability on this landscape. Bison also selected roads and anthropogenic clearings associated with resource development, demonstrating potential for human–wildlife conflict. Our predictive maps highlight areas of conservation interest, and should be considered in land use planning and environmental assessments. We demonstrate the value of foraging habitat for forest-dwelling bison, particularly in winter. Identifying forage-rich habitat patches, and connectivity between them, is important when considering sites for new reintroductions or expansion of existing populations. More broadly, our approach may be used to identify areas of high conservation interest, where resources do not allow extensive sample sizes of GPS-collared animals. [ABSTRACT FROM AUTHOR]

The public is occasionally concerned about the detrimental impact of wildlife research activities, particularly capture procedures such as the use of chemical immobilization. One of the risks inherent with chemical immobilization is aggression (or predation) to immobilized animals by conspecifics; yet, data on such occurrences are rarely reported in the literature. We chemically immobilized 25 dominant age-class, large-bodied adult male bison (Bison bison). We observed seven instances (28%) of dominant adult male bison attacking a conspecific that was lying down shortly after being chemically immobilized. Incidences of attacks by aggressive males were more frequent during ground-based versus helicopter-based captures, but this difference was not statistically significant. Contrary to our prediction, we found no difference in the frequency of attacks during mid-summer or late-winter. Our observations highlight the aggressive nature of dominant male bison toward conspecifics and serve as a cautionary note to others chemically immobilizing them. With a marked interest in restoring bison to, and better understanding their ecological role in, their native landscapes, it is anticipated that capturing bison for research and conservation purposes will become more common. We provide suggested best practices so that protocols may be implemented to reduce potential injuries to immobilized bison from conspecifics, and these may also apply to other large, aggressive ungulates. [ABSTRACT FROM AUTHOR]

Ecological interactions between ungulates and small mammals are generally not well understood. Here, we report an observation of unusually extensive small mammal (likely Meadow Vole [Microtus pennsylvanicus] or Tundra Vole [Microtus oeconomus]) tracks above the snow, exiting from trails and bed sites created by Bison (Bison bison) in northern Canada. We believe that weather and snow conditions were optimal for this observation. Although alteration of above-snow activity of small mammals in response to snow compaction by ungulates is probably not a rare event, it is not often reported. The effect on voles of exiting their subnivean tunnels as a result of Bison activity is unclear, but may be detrimental to their overwinter survival. Ungulate activity compacts snow, fragmenting small mammal tunnels resulting in loss of their insulative value for voles, and making it harder for them to dig new tunnels. Clearly, determining the effect of snow disturbance by gregarious ungulates on voles or other microtines, particularly regarding their overwinter survival, requires detailed investigation. Nevertheless, this observation provides new information on the ecological interactions between ungulates and small mammals, particularly from the boreal forest, where such information is largely lacking. [ABSTRACT FROM AUTHOR]

The timing of parturition in high-latitude populations of Bison (Bison bison) is not well documented, but previous observations have indicated that births do not start until mid-May and largely end in late June or early July, similar to those of other northern ungulates. In three high-latitude Bison populations in northwestern Canada, the onset of parturition occurred as early as late March and early April--5-6 weeks earlier than previously observed--and two isolated cases of late births occurred in mid-November and mid-December. Our observations suggest that the onset of parturition in high-latitude Bison can be earlier than previously known, and late births, while apparently rare, may occur. Determining whether our observations signal a substantial, lasting shift in the timing and, possibly, synchrony of parturition in high-latitude populations of Bison will require further monitoring for early-born calves. [ABSTRACT FROM AUTHOR]

Recently, a new generation of global positioning system (GPS) collars has become available that provides limited daily location fixes, a relatively long battery life, and are low‐cost, compared to full‐featured GPS collars. However, their performance is untested, and assessing these biases is needed to inform study designs and data analysis protocols. We used stationary tests of 15 Lotek LifeCycle GPS collars – an example of low‐feature GPS collars – to measure the accuracy of location fixes. In addition, we deployed Lotek Lifecycle GPS collars on 153 caribou Rangifer tarandus and 24 bison Bison bison in Yukon and Alaska, to assess their field performance. We examined differences among species, sex, location fix schedule, and latitude, on four performance metrics (FSR, 3D‐V FSR, DOP and DSR). Stationary trials indicated that mean precision (4.3 ± 4.0 m [SD]) and accuracy (6.0 ± 4.7 m) of location fixes was excellent, and FSR was good (87.2%), albeit both were slightly affected by forest canopy cover. Field performance varied by species and sex. Notably, the mean DSR for male bison was dismal (27.4 ± 24.2%) likely because of their behaviour, and the mean FSR, 3DV‐FSR and DOP, for male caribou was poor (FSR = 57.3 ± 2.0%), compared to collars deployed on female caribou (72.2 ± 1.7%) or female bison (77.9 ± 1.4%). We also observed that the VHF transmitters often failed when the collar malfunctioned. Biases in the accuracy and performance of these low‐cost GPS collars should be taken into account when designing studies. Researchers contemplating investing in low‐feature GPS collars require information on their 'real‐world' performance so that they can decide whether they are appropriate for their intended application. Moreover, researchers need to consider biases in their GPS collar data prior to embarking on field studies and when conducting analyses with the data collected from them. [ABSTRACT FROM AUTHOR]

Context. Global positioning system (GPS) collars are increasingly used to study animal ecology.However,understanding their real-world performance is important so that biases in data collection can be addressed. These biases may be species specific. Few studies have examined the influence of sex or temporal variation on locational fix success rates (FSR), and none has assessed GPS-collar performance on bison (Bison bison). Aims. To test for sex- and temporal-based biases on the performance of GPS collars on free-ranging bison. Methods. Data from 59 deployments of 37 GPS collars on 27 female and seven male bison was used to test for temporal variation and differences between sexes on collar-deployment success rates and four fix acquisition metrics. Key results. Most (72.9%) of the 55 GPS collars retrieved malfunctioned before reaching their expected deployment schedule (2 years). We observed a significant difference in the performance of GPS collars deployed on male and females, with those on females functioning almost three times longer. All four fix metrics differed between sexes, with males having significantly better metrics. For females, nightly fix metrics were better than the daytime ones, whereas for males, there was no difference. We observed a significant difference in fix metrics between seasons for females, but not males. Conclusions. Although the data from GPS collars may be useful in understanding animal ecology, understanding associated biases can aid in the design of field studies using, and the interpretation of results stemming from, GPS collars. Temporal variation in our study was apparent for females, but not males, and likely related to differences in habitat use and movements. Overall, sex had a significant influence on the success of GPS-collar deployments on bison, and should be examined for other species as well. Implications. Bison damage to the collars was the main reason for collar failures. Researchers should plan for catastrophic failures and malfunctions when deploying GPS collars on bison, particularly adult males. Significant differences observed between daily and seasonal FSR for females were small (<4.9%), and do not warrant post hoc treatment before analyses. [ABSTRACT FROM AUTHOR]

The article investigates the predatory behavior of gray wolf in scavenging of reintroduced scavenging American bison in southwestern Yukon. It cites several incidents of bison predation by wolves in 2007 and 2009 but no wolves were directly observed preying on bison because only the rumen remained in the scene. It cites that several sporadic, aerial, and occasional observations were conducted but none had been reported on scavenging of predation of bison. It states that predation of wolf on bison may have substantial implication for the population dynamics of both species and alternate species, and that scavenging are important ecological processes.

The article discusses the social impact of the reintroduction of American Bison (Bison bison) as part of a national recovery program in southwestern Yukon Canada. It lists its several ecological functions which is said to be of great significance in evaluating their restoration in the ecosystem. It notes the different observations that were documented on the used of bison's fur as nesting materials by birds and small mammals including the American Red Squirrels (Tamiasciurus hudsonicus). The latter's nests including the types of fur used are evaluated.

One of the more unique aspects of the natural history of muskrats (Ondatra zibethicus) is that during early winter they construct push-ups—piles of frozen vegetation—on the surface of frozen lakes. Push-ups are a potentially valuable source of relatively high-quality forage for northern ungulates, which typically become increasingly nutritionally deprived during winter. Because of concerns by local people that reintroduced bison (Bison bison) were eating muskrat push-ups and causing a decline in some local populations, we assessed the comparative value of push-ups as late-winter forage for bison. We collected vegetation from 18 push-ups and 18 shoreline sites (i.e. wet sedge meadows), distributed equally from 3 lakes, and used wet chemistry techniques to assess their nutritional quality (i.e. percent crude protein, neutral detergent fibre, lignin, and total digestible nutrients, plus major and trace minerals). General linear models revealed that most variables assessed differed significantly by SITE (push-up versus shoreline; 13 of 15 variables), LAKE (3 lakes; 9 of 15), and their interaction (SITE*LAKE; 11 of 15). Our data suggest that muskrat push-ups may provide a supplement to winter forage used by bison in our study area by helping to boost protein intake as well as providing minerals that may be deficient in their late-winter diets, such as Ca, Fe, and Cu. As such, bison should seek push-ups in late winter to supplement their diet and improve their nutritional condition at a time when they may be seasonally impoverished. Our study also demonstrates that nutritional quality of push-ups varies significantly between nearby lakes—likely due to their unique biogeochemistry. As such, muskrat push-ups on some lakes may be more favoured by bison than those on other lakes. Whether our results may be extended to other species of northern ungulates or other ecological regions, however, awaits testing. [ABSTRACT FROM AUTHOR]