A lot of the current research related to caribou populations in Alberta (and throughout Canada, for that matter) seeks to answer questions related to understanding why woodland and mountain caribou herds are in decline.
One of the primary themes is predation – the role played by predators (wolves, primarily, but also bears, wolverine, cougar or coyote) and alternate prey (other ungulates such as moose and white-tail deer) in caribou mortality rates. Related research in the area of habitat selection and preferences- by caribou, their predators or alternate prey - is also ongoing.
The following are links to some of the most recent peer-reviewed publications in this vein. Note that in some cases the full text of the article may not be available online without a subscription.
- Wasser, S.K., J. Keim, M. Taper and S. Lele. 2011. The influences of wolf predation, habitat loss, and human activity on caribou and moose in the Alberta oil sands. Frontiers in Ecology and the Environment. 9: 546-551.
Looked at the effect of petroleum development activities on wolf, caribou and moose in northeastern Alberta. Changes in stress levels and resource selection were noted but population numbers were stable over the 4-year study period. Concludes that changes in human-made disturbances may be more effective at population management than removing wolves from the landscape.
- Whittington, J., M. Hebblewhite, N. DeCesare, L. Neufeld, M. Bradley, J. Wilmshurst, M. Musiani. 2011. Caribou encounters with wolves increase near roads and trails: a time-to-event approach. Journal of Applied Ecology. Vol. 48, No. 6. pp. 1535-1542.
Looks at specific aspects of wolf & caribou interactions, including how wolves used caribou range (higher elevations during the summer), influence of anthropogenic features, as well as density of wolf population. Shows that linear features and time spent within the caribou range are as important as wolf density when looking at caribou recovery.
- Latham, A.D.M., M.C. Latham, N. McCutchen, S. Boutin. 2011. Invading white-tailed deer change wolf-caribou dynamics in northeastern Alberta. The Journal of Wildlife Management. Vol. 75, No. 1, pp. 204-212.
Looks at the effect of moose and deer populations on wolf populations, and the resulting effect on caribou population. Deer populations increased substantially, as did wolf population, and wolf predation on caribou increased markedly as well. As deer encroach on caribou range, wolves follow the deer and then prey more heavily on caribou than they would have otherwise.
- Latham, A.D.M., M.C. Latham, M.S. Boyce. 2011. Habitat selection and spatial relationships of black bears (Ursus americanus) with woodland caribou (Rangifer tarandus caribou) in northeastern Alberta. Canadian Journal of Zoology. Vol. 89, No. 4.
Looks at the spatial relationships of caribou and black bears in northeastern Alberta. Although in general caribou select habitat that is not favoured by bears, some bears do select habitat similar to caribou, and are probably responsible for some caribou mortality, particularly during the vulnerable calving season.
- Houle, M., D. Fortin, C. Dussault, R. Courtois, J. Ouellet. 2010. Cumulative effects of forestry on habitat use by gray wolf (Canis lupus) in the boreal forest. Landscape Ecology. Vol. 25, No. 3. pp. 419-433.
Looks at the cumulative effects of forestry on habitat selection in wolves in the boreal forests of Quebec. Understanding how roads and cutblocks affect wolf habitat selection can help with our understanding of wolf/caribou dynamics, and affect decision-making for wildlife conservation and management.
- Courbin, N., D. Fortin, C. Dussault, R. Courtois. 2009. Landscape management for woodland caribou: The protection of forest blocks influences wolf-caribou co-occurance. Landscape Ecology. Vol. 24, No. 10. pp. 1375-1388.
Looks at caribou and wolves in Quebec forests and the probability of co-occurance. Caribou selected for different forest types than wolves, selecting against roads and cutblocks, where wolves selected for roads and cutblocks. This means that when planning mitigation measures, areas of the forest protected for caribou would need to be far away from roads and cutblocks in order to minimize predation by wolves.
- Briand, Y., J. Ouellet, C. Dussault, M. St-Laurent. 2009. Fine-scale habitat selection by female forest-dwelling caribou in managed boreal forests: Empirical evidence of a seasonal shift between foraging opportunities and antipredator strategies. Ecoscience. Vol. 16, No. 3. pp. 330-340.
Looks at the habitat-selection patterns of caribou in winter and summer. Winter selection was based on lichen availability, while summer selection seemed to be based on finding habitat that wasn't selected by other ungulates and therefore wolves.
- Hins, C., J. Ouellet, C. Dussault, M. St-Laurent. 2009. Habitat selection by forest-dwelling caribou in managed boreal forest of eastern Canada: Evidence of a landscape configuration effect. Forest Ecology and Management. Vol 257, No. 2. pp. 636-643.
Tracked the habitat selections of 15 female caribou in the Quebec boreal forest for several years. Caribou seemed to prefer old forests, rarely selected regenerating forests, and sometimes selected clearcuts. Understanding caribou habitat needs could help determine best practices for forest harvesting.
- Arsenault, A., M. Manseau. 2011. Land management strategies for the long-term persistence of boreal woodland caribou in central Saskatchewan. Rangifer. Vol. 31, No. 2.
Studies caribou in central Saskatchewan, in particular looking at how the use the forest. Lots of roads and trails mean that caribou stay in smaller home ranges, and choose calving sites as far as possible from disturbances. Suggests that providing caribou with less fragmented habitat would improve their survival.
- Seip, D. 2008. Mountain caribou interactions with wolves and moose in central British Columbia. Alces: A Journal Devoted to the Biology and Management of Moose. Vol. 44.
Looks at caribou populations in central BC, related to wolf and moose populations. Results indicate that increases in moose populations lead to increases in wolf populations and decreases in caribou populations.
- Bowman, J., J. Ray, A. Magoun, D. Johnson, F. Dawson. 2010. Roads, logging and the large-mammal community of an eastern Canadian boreal forest. Canadian Journal of Zoology. Vol. 88, No. 5.
Looks at the presence of large mammals in two areas of Ontario - deciduous forest and coniferous forest, with the deciduous forest having roads and cutovers from logging. Caribou were found to occur most in mature coniferous forests, and least in areas with high occurance of wolves and/or roads.
More to come!
