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Woodland caribou (Rangifer tarandus caribou) are declining across much of their distribution in Canada in response to habitat alteration, leading to unsustainable predation, particularly by wolves (Canis lupus). Habitat alteration can benefit the primary prey species of wolves (moose [Alces alces] and deer [Odocoileusspp.]) by creating early seral conditions that contain more of their preferred food types. This increase in primary prey populations results in elevated wolf abundance and heightened predation pressure on caribou. In response to the elevated wolf populations and the risks to caribou, managers have reduced wolf abundance in key areas. Ecological theory suggests that reducing wolf abundance would release moose from the top‐down effects of wolf predation, potentially allowing moose populations to grow. Elevated moose abundance thus has the potential to cause wolf populations to rebound quickly each year following reductions, suggesting a possible link between moose abundance and the number of wolves killed for caribou conservation. To test this idea we used a unique management situation in British Columbia and Alberta, Canada, where lethal wolf removals were annually conducted across specific southern mountain caribou population ranges and, in some places, moose populations were concurrently reduced via liberalized hunting. We used indices of moose abundance and wolf removal data to test the hypothesis that reducing moose populations to a historical abundance target by hunting leads to fewer wolves killed for caribou conservation. After controlling for habitat quality, wolves removed per km2was 3.2 times lower in areas with reduced moose density (x¯$\bar{x}$= 1.55 wolves/1,000 km2± 0.33 [SE]) than in those without reduced moose density (x¯$\bar{x}$= 5.02 wolves/1,000 km2± 0.52). However, the average number of wolves removed per year decreased under both conditions. After 9 years, there was a 35% reduction in the predicted difference in the annual removal between areas with and without moose reduction. Our results suggest that policies that do not reduce or stabilize moose abundance will result in the removal of more wolves to increase caribou abundance. Like wolf reductions, moose reductions can also be controversial and affect local harvesters. Thus, understanding the consequences of actions that support caribou recovery is essential to supporting evidence‐based policy discussions. Habitat alteration is causing woodland caribou populations to decline owing to increased predation by wolves, which benefit from the increased abundance of their primary prey, moose. Management strategies, including reducing wolf populations and increasing moose hunting opportunities enough to sufficiently affect wolf populations, have shown potential to meet short‐term caribou conservation objectives. This study suggests that without moose reductions, more wolves will need to be removed to meet caribou conservation targets.

Canada's federal recovery strategy for boreal woodland caribou (Rangifer tarandus caribou) classifies areas burned by forest fire as disturbed habitat. This assignment of fire as a disturbance has potential economic and social implications across Canada, and influences plans and actions to achieve caribou conservation and recovery. Previous researchers have reported caribou avoid burned habitat, but these studies did not typically consider unburned residual patches within fire perimeters. Additionally, the implications of burned habitat on individual caribou survival is unclear. We examined resource selection by boreal woodland caribou of burns, and unburned residual patches, using global positioning system (GPS) locations for 201 caribou across 6 caribou populations in Alberta, Canada. We also examined if burned habitat affected the survival of adult female caribou. Caribou avoided burns and unburned residual patches. Increased use of burned habitats, however, did not lower the survival of adult caribou. Collectively, these results provide evidence to support current assertions that burns, and the embedded unburned residual patches are not preferred caribou habitat and increase our understanding of the implications of forest fire for caribou vital rates. Our investigation offers important information about the role of forest fire in caribou ecology and enhances the identification of disturbed habitat under recovery strategy guidelines to effectively address caribou population declines. © 2021 The Wildlife Society. Woodland caribou in Alberta, Canada avoid burned habitat including unburned residual patches; however, there was no relationship between burned habitat use and adult female survival. This suggests fire disturbance is not a key influence of caribou population persistence, and we recommend reevaluation of the current approach listed in the federal boreal caribou recovery strategy that includes anthropogenic and fire disturbance in a cumulative assessment of disturbed habitat.

Understanding how landscape change influences the distribution and densities of species, and the consequences of these changes, is a central question in modern ecology. The distribution of white‐tailed deer (Odocoileus virginianus) is expanding across North America, and in some areas, this pattern has led to an increase in predators and consequently higher predation rates on woodland caribou (Rangifer tarandus caribou)—an alternate prey species that is declining across western Canada. Understanding the factors influencing deer distribution has therefore become important for effective conservation of caribou in Canada. Changing climate and anthropogenic landscape alteration are hypothesized to facilitate white‐tailed deer expansion. Yet, climate and habitat alteration are spatiotemporally correlated, making these factors difficult to isolate. Our study evaluates the relative effects of snow conditions and human‐modified habitat (habitat alteration) across space on white‐tailed deer presence and relative density. We modeled deer response to snow depth and anthropogenic habitat alteration across a large latitudinal gradient (49° to 60°) in Alberta, Canada, using motion‐sensitive camera data collected in winter and spring from 2015 to 2019. Deer distribution in winter and spring were best explained by models including both snow depth and habitat alteration. Sites with shallower snow had higher deer presence regardless of latitude. Increased habitat alteration increased deer presence in the northern portion of the study area only. Winter deer density was best explained by snow depth only, whereas spring density was best explained by both habitat alteration and the previous winter's snow depth. Our results suggest that limiting future habitat alteration or restoring habitat can alter deer distribution, thereby potentially slowing or reversing expansion, but that climate plays a significant role beyond what managers can influence. © 2020 The Wildlife Society. In Alberta, Canada, sites monitored using motion‐sensitive cameras between 2015 and 2019 were more likely to have deer present with shallower snow and increased habitat alteration. At sites where deer were present, density was higher in areas with lower snow in winter but with greater habitat alteration in spring. Our results suggest that restoring habitat and limiting future habitat alteration can partially control deer distribution but that climate plays a significant role beyond what managers can influence.

Habitat disturbance threatens woodland caribou (Rangifer tarandus caribou) by altering inter‐tropic relationships, which causes predation rates to increase. Of particular concern is the increase in early seral vegetation in high‐elevation caribou summer habitat created by the recent expansion of logging into these forests. Deep snow confines the relatively abundant moose (Alces alces) population to valleys during winter, but in summer they can move up slope, where their spatial overlap with caribou increases. Wolves (Canis lupus) follow moose, their primary prey, up slope and occasionally encounter and kill caribou. We tested the hypothesis that early seral vegetation in high‐elevation cutblocks (i.e., logged areas) attracts moose into mountain caribou summer habitat, and thereby increases the spatial overlap between caribou, moose, and wolves. To test our hypothesis, we examined how moose selection for early seral vegetation changed with elevation, how moose used undisturbed habitat, and how the proportion of early seral vegetation at high elevations in a moose home range was related to the amount of time moose spent at high elevations. Moose selection for cutblocks increased with elevation; however, when moose were at high elevations they spent the majority of their time in old‐growth forest where they were likely browsing on understory shrubs, and the area of high‐elevation cutblocks in moose home ranges did not affect the amount of time moose spent at high elevations. When we further explored the relationship between the amount of early seral vegetation at high elevations and the amount of time moose spent at high elevations, we found moose spent more time at high elevations when total early seral vegetation (from natural sources and cutblocks) increased, but there was little evidence that either type, on their own, influenced moose to use higher elevations. We conclude that although moose select cutblocks, the influence of high‐elevation cutblocks on moose was minor in our study. Our results and those of other studies suggests low‐elevation logging in moose winter ranges has led to an increased number of moose, and likely has a greater effect on moose distribution than logging at higher elevations. These insights can help guide management of apparent competition between moose and caribou. © 2017 The Wildlife Society. We studied moose use and selection of high‐elevation cutblocks (i.e., logged areas) in the context of managing apparent competition with mountain caribou. We found that moose select high‐elevation cutblocks, but the area of high‐elevation cutblocks does not influence the amount of time moose spend in caribou habitat unless it is combined with the area of naturally occurring early seral vegetation. We recommend that forest management for mountain caribou consider total early seral vegetation rather than just anthropogenic disturbances, and be elevation specific.

Mountain caribou are an endangered ecotype of woodland caribou (Rangifer tarandus caribou) that historically occurred throughout the high snowfall regions of southeast British Columbia and the northwestern United States. The decline in caribou is thought to be due to apparent competition where increases in early-seral conditions stimulate a numerical response in primary ungulate prey and their predators and these incidentally kill an unsustainable number of caribou. Based on the known location of death of 207 radio collared animals, we tested hypotheses pertaining to relationships between landscape composition and predator-specific mortality of mountain caribou at 2 ecologically based spatial scales. Relative to landscape conditions within subpopulation boundaries (level 1) or within home ranges (level 2), caribou were at greater risk of predation at low elevations particularly within otherwise complex terrain (i.e., valleys) with more variation in overstory canopy closure and greater road densities. Caribou vulnerability to bears was also positively related to the variation in overstory age. Cougar predation was not related to roads or terrain complexity but occurred more often in landscapes with warmer aspects and greater proportions of stands of <120 years. Wolf predation occurred primarily at low elevations at the broader scale and in association with roads at the finer scale. Our results indicate that caribou vulnerability to predation was a function of both static (e.g., terrain) and dynamic (e.g., overstory conditions) factors, but we did not find evidence that localized habitat fragmentation due to forest harvest influenced predation on caribou. This result is not inconsistent with the apparent competition hypothesis but suggests that habitat change largely functions at broader spatial scales involving landscapes that can be beyond those occupied by caribou, including the winter ranges of primary ungulate prey. These changes and the season-dependent dispersion of other ungulates and their predators may largely influence mortality risk to mountain caribou. Although roads and forest fragmentation are interrelated, roads may further contribute to caribou predation by increasing the efficiency of movement of some predators and thereby increasing encounter rates with caribou. © 2013 The Wildlife Society.

In mountainous areas with sufficient snowfall, avalanche chutes are an important component of grizzly bear (Ursus arctos) habitat. Therefore, regional land-use plans have recommended retaining adjacent forest buffers to maintain security and thus reduce potential impacts of clearcut forest harvesting. Our objective was to determine if forest buffers affected selection of avalanche chutes by grizzly bears, while accounting for factors such as vegetation composition and other physical attributes. We used radio-location data from 61 grizzly bears collected between 1994 and 2000 in southern British Columbia, mapped a sample of avalanche chutes (1,045), and quantified the amount of forb, shrub, tree, and non-vegetated cover within each chute. We also measured forested buffer width on each side of the chute, solar radiation, chute size, chute frequency (no. of chutes/km), and the area of clearcut logging adjacent to chutes. Each avalanche chute was the sample unit and the number of grizzly bear radiolocations was the dependent variable. We found that natural biophysical attributes were the strongest factors predicting the level of avalanche chute use by bears. Frequency of large chutes (>100?m wide), chute area, forb content, and solar radiation all positively affected use by bears. Larger avalanche chutes had a higher proportion of forb cover than smaller chutes, and more of these large chutes per unit area provided increased forage opportunities. Based on multivariate analyses, forested buffer width or the amount of clearcut logging were not strong factors predicting the level of use. However, a post hoc univariate analysis revealed that clearcut logging reduced the amount of bear use of the best avalanche chutes (large and abundant chutes). Furthermore, because a portion of our study area contained logging but no vehicle traffic, we concluded that it was the removal of tree cover, rather than displacement by vehicles, that caused the observed pattern. Although our multivariate models did not perform well using independent validation in a different geographic area, 4 factors were consistently important (large and abundant chutes, forb content, with a negative but weaker influence of clearcutting), suggesting broad applicability of these factors in mountainous ecosystems. © 2011 The Wildlife Society.

Parturient ungulates are relatively more sensitive to predation risk than other individuals and during other times of the year. Selection of calving areas by ungulates may be ultimately related to trade-offs between minimizing risk of predation and meeting nutritional needs for lactation. We used digital and field data to examine selection of calving areas by 31 global positioning system–collared moose (Alces alces) in southeastern British Columbia. We examined movements 12 days before and after calving, and analyzed habitat selection at 2 scales of comparison: the immediate calving area to the extended calving area (100 ha), and the extended calving area to the surrounding home range. Maternal moose exhibited 1 of 2 distinct elevational strategies for calving area selection during the days leading up to calving: 16 moose were climbers and 15 were nonclimbers. Climbers moved a mean of 310 m higher in elevation to calve, whereas nonclimbers showed little change in elevation. Hourly movements by all maternal females increased 2- to 3-fold in the 1–4 days before calving and were generally directional, such that all calving areas were outside of areas used during the 12 days before calving. At the broad scale, elevation was the strongest predictor of the extended calving area within the home range. At the fine scale, climbers selected areas with reduced tree density, reduced forage, and increased distance from water, whereas nonclimbers selected areas with increased forage, decreased distance from water, and decreased slope. Beyond the obvious elevation difference between climbers and nonclimbers, moose appeared to exhibit 2 distinct calving strategies in mountainous ecosystems. A functional explanation for the 2 strategies may be that climbers moved into areas where forage quantity and quality were relatively low, but where risk of predation (mainly by grizzly bears [Ursus arctos]) also was reduced. Nonclimber moose calved in areas with higher forage values, and appeared to select areas at the finer scale to reduce predation risk (e.g., association with water and reduced tree density for visibility).

We tracked 12 mule deer (Odocoileus hemionus hemionus) between February 1999 and April 2003 by using global positioning system (GPS) radiotelemetry in southeastern British Columbia to provide detailed information on migration and habitat use to local managers. We tested winter resource selection at the home-range and within-home-range scale to test a hypothesis that ungulate resource selection is scale-dependent. All sampled mule deer in this population migrated from low-elevation winter ranges to high-elevation summer ranges, supporting a hypothesis that migration is obligatory in mountainous, heavy-snow areas. We found little consistent selection at the within-home-range scale, but considerable selection at the home-range scale, supporting a scale-dependent hypothesis. Potential mule deer winter range could be predicted from 2 biophysical attributes, elevation and solar duration. Currently suitable winter habitat can then be further delineated on the basis of amount of mature coniferous forest within this zone. Use of GPS radiotelemetry increased sample intensity of individual deer, and thereby accuracy of individual parameter estimates. However, because of high equipment costs and failure rates, increased sample intensity occurred at the expense of sample size, and therefore illustrates a trade-off consideration for future work.