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Mountain caribou are an endangered ecotype of woodland caribou (Rangifer tarandus caribou (Gmelin, 1788)) that continue to decline, ultimately, due to habitat loss and, proximately, due to predation. A particularly imperilled population of mountain caribou was experimentally augmented with 19 northern caribou, a geographically distinct ecotype, from northern British Columbia. We examined seasonal variation in risk of predation by cougars (Puma concolor (L., 1771)) to the translocated caribou with comparison to resident caribou. Our basic approach followed the Movement Ecology Paradigm, in particular the interplay among why move, and when and where to move. We applied a cluster analysis framework on space-use patterns of GPS radio-collared animals to determine biologically relevant seasons. Then we examined the spatiotemporal similarity in habitat use between caribou groups and cougars across these seasons. This analysis included a control group of caribou from the donor herd that were not translocated. Five resident caribou seasons, two donor caribou seasons, and two cougar seasons were identified. Resident caribou remained at high elevations year-round and primarily selected habitats not used by cougars. In contrast, translocated caribou tended to occupy low-elevation habitats extensively used by cougars, resulting in predation of eight translocated caribou, six of which were by cougars. We concluded that the translocated caribou did not adopt the predator avoidance strategies of resident caribou, rendering them more vulnerable to predation. We make recommendations for future herd augmentations, notably that donor caribou should be of the same ecotype, have similar seasonal patterns of habitat use and associated behavioural repertoires, and be exposed to the same complex of predators.

Managing predators to restore threatened or endangered species is often controversial. Hervieux et al. (2014; Can. J. Zool. 92(12): 1029–1037) report on the efficacy of wolf (Canis lupus L., 1758) reduction as a recovery strategy in the Little Smoky population of boreal woodland caribou (Rangifer tarandus caribou (Gmelin, 1788)) range in Alberta, which generated a lot of media attention. As such, the authors were invited by the journal editor who handled the original paper to write this addendum to provide clarification regarding the methodology used in the original paper. Wolf reduction was conducted by Government personnel in accordance with appropriate policy and laws (i.e., federal and provincial Species at Risk Acts; Alberta Wildlife Act; Alberta Woodland Caribou Policy). University-based researchers were involved only in data analysis and writing, and thus did not require approval by a university-based animal welfare board. Collaboration between independent university-based scientists and government biologists is essential to effective assessment of such controversial management practices. Hervieux et al. (2014; Can. J. Zool. 92(12): 1029–1037) in fact concluded that such wolf reductions, by themselves, would only “buy time” and would not restore woodland caribou alone without effective habitat protection.

Caribou ( Rangifer tarandus (L., 1758)) play a central role in the ecology and culture of much of Canada, where they were once the most abundant cervid. Most populations are currently declining, and some face extirpation. In southern Canada, caribou range has retreated considerably over the past century. The ultimate reason for their decline is habitat alterations by industrial activities. The proximate causes are predation and, to a lesser extent, overharvest. The most southerly populations of “Mountain” caribou are at imminent risk of extirpation. Mountain caribou are threatened by similar industrial activities as Boreal caribou, and face increasing harassment from motorized winter recreational activities. Most populations of “Migratory Tundra” caribou are currently declining. Although these caribou fluctuate in abundance over decades, changing harvest technologies, climate change, increasing industrial development and human presence in the North raise doubts over whether recent declines will be followed by recoveries. The Peary caribou ( Rangifer tarandus pearyi J.A. Allen, 1902), a distinct subspecies endemic to Canada’s High Arctic, has suffered drastic declines caused by severe weather, hunting and predation. It faces an increasing threat from climate change. While some questions remain about the reasons for the decline of Migratory Tundra caribou, research has clearly identified several threats to the persistence of “Boreal”, Mountain, and Peary caribou. Scientific knowledge, however, has neither effectively influenced policies nor galvanized public opinion sufficiently to push governments into effective actions. The persistence of many caribou populations appears incompatible with the ongoing pace of industrial development.

Mountain caribou, an endangered ecotype of woodland caribou ( Rangifer tarandus caribou Gmelin, 1788), live in late-successional coniferous forests where they depend largely on arboreal lichens as winter forage. While radio-telemetry has been used to understand caribou habitat selection patterns at broad scales among and within populations, here we use snow-trailing in old cedar–hemlock forests between 1992 and 2003 to study three finer scales of habitat selection: (1) forest stands used for foraging from available forest stands (among-stand selection), (2) foraging paths within selected stands relative to random paths within those same stands (within-stand selection), and (3) feeding items along foraging paths. Relative to stands that were available on the landscape, caribou selected stands with more windthrown trees and standing snags. Within stands, caribou selected paths that had more live trees, snags with branches and bark, and trees with larger diameters. All of these habitat attributes facilitate access to arboreal lichen. Of the potential forage items encountered along foraging paths, caribou preferred to feed on windthrown trees, lichen litterfall and falsebox ( Paxistima myrsinites (Pursh.) Raf.). Our results go beyond telemetry studies by revealing that not all old forests are of equal value to mountain caribou. Prioritization among old stands will help refine conservation measures, as will silvicultural systems that incorporate key habitat attributes to maintain winter habitat in low-elevation cedar–hemlock ecosystems.

We used census results and radiotelemetry locations of >380 collared individuals sampled over the entire distribution of the endangered mountain ecotype of woodland caribou (Rangifer tarandus caribou (Gmelin, 1788)) in British Columbia, Canada, to delineate population structure and document the size and trend of the identified populations. We also describe the spatial pattern of decline and the causes and timing of adult mortality and provide estimates of vital rates necessary to develop a population viability analysis. Our results indicate that the abundance of mountain caribou in British Columbia is declining. We found adult female annual survival rates below annual survival rates commonly reported for large ungulates. The major proximate cause of population decline appears to be predation on adult caribou. Spatial patterns of population dynamics revealed a continuous range contraction and an increasing fragmentation of mountain caribou into smaller, isolated subpopulations. The population fragmentation process predominantly occurs at the outer boundaries of the current distribution. Our results indicate that recovery strategies for mountain caribou should be directed at factors contributing to the fragmentation and isolation of mountain caribou populations as well as management strategies aimed at increasing adult survival.

Woodland caribou (Rangifer tarandus caribou) in Alberta are classified as endangered and apparently have declined. Disturbance from petroleum exploration has been implicated as a possible cause, so we constructed a simple model to estimate the energy costs of multiple encounters with disturbance (i.e., loud noise). Our objective was to estimate if woodland caribou in northeastern Alberta have been exposed to enough disturbance from 1988 to 1993 to cause winter mass loss to exceed either (i) 15% autumn mass or (ii) 20% autumn mass. A single disturbance event costs caribou 3.46-5.81 MJ. Caribou would have to encounter (i) 20-34 (mean = 27) disturbance events to lose >15% mass over winter and (ii) 41-137 (mean = 89) events to lose >20% mass. There were five occasions from 1988 to 1993 (i.e., in a particular caribou distribution zone and winter) when the encounter rate (number of potential encounters per square kilometre) exceeded a level expected to result in caribou losing more than the estimated mean 15% autumn mass. There were four occasions when the encounter rate exceeded the lower limit expected to cause >20% mass loss and one occasion when it approached the mean rate expected to cause >20% mass loss. Modelling the cumulative influence of disturbances demonstrates an effect on individual energy loss during winter at certain exploration intensities. It is the first attempt at estimating the consequences of petroleum exploration for wildlife in northeastern Alberta and provides important information for future research and land-use management.

Woodland caribou in northeastern Alberta are relatively sedentary, occur at low densities, and are classed as endangered in Alberta. Increasing encroachment of the forest and petroleum industries into the southern regions of the boreal woodland caribou range has highlighted the need for detailed habitat analysis for this species. We obtained approximately 1000 locations of 47 woodland caribou fitted with very high frequency telemetry collars, providing data on winter habitat use from 1991 to 1994. Telemetry data were combined with digital peatland coverages that best represented lowland habitat diversity. Woodland caribou selected forested fen peatland complexes at both the population and individual spatial scales. Woodland caribou concentrated feeding activity in forested, raised bog islands. The raised bogs provide more xeric substrate for increased lichen biomass, possibly a key factor in their selection during winter. The hypothesized connection between discontinuous permafrost and the maintenance of raised bog islands in terms of caribou forage distribution and availability is discussed.