scholarly journals Woodland caribou population decline in Alberta: fact or fiction?

Rangifer ◽  
1996 ◽  
Vol 16 (4) ◽  
pp. 223 ◽  
Author(s):  
Corey J.A. Bradshaw ◽  
Daryll M. Hebert
Keyword(s):  
Wildlife Management ◽  
Canis Lupus ◽  
Rangifer Tarandus ◽  
Population Decline ◽  
Population Fluctuations ◽  
Woodland Caribou ◽  
Subsistence Hunting ◽  
The Past ◽  
Adequate Information ◽  
Aboriginal Subsistence

We re-assessed the view of a major woodland caribou (Rangifer tarandus caribou) population decline in Alberta. Several historical publications and provincial documents refer to this drastic decline as the major premise for the designation of Alberta's woodland caribou an endangered species. In the past, wildlife management and inventory techniques were speculative and limited by a lack of technology, access and funding. The accepted trend of the decline is based on many speculations, opinions and misinterpretation of data and is unsubstantiated. Many aerial surveys failed to reduce variance and did not estimate sightability. Most surveys have underestimated numbers and contributed unreliable data to support a decline. Through forest fire protection and the presence of extensive wetlands, the majority of potential caribou habitat still exists. Recreational and aboriginal subsistence hunting does not appear to have contributed greatly to mortality, although data are insufficient for reliable conclusions. Wolf (Canis lupus), population fluctuations are inconclusive and do not provide adequate information on which to base prey population trends. The incidence of documented infection by parasites in Alberta is low and likely unimportant as a cause of the proposed decline.

Managing wolves (Canis lupus) to recover threatened woodland caribou (Rangifer tarandus caribou) in Alberta

2014 ◽  
Vol 92 (12) ◽  
pp. 1029-1037 ◽  
Author(s):  
Dave Hervieux ◽  
Mark Hebblewhite ◽  
Dave Stepnisky ◽  
Michelle Bacon ◽  
Stan Boutin
Keyword(s):  
Canis Lupus ◽  
Rangifer Tarandus ◽  
Apparent Competition ◽  
Provincial Government ◽  
Population Increase ◽  
Rangifer Tarandus Caribou ◽  
Wolf Population ◽  
Woodland Caribou ◽  
Population Reduction ◽  
Reduction Program

Across Canada, woodland caribou (Rangifer tarandus caribou (Gmelin, 1788)) populations are declining because of human-induced changes to food webs that are resulting in apparent competition-induced increases in predator-caused caribou mortality. We tested the hypothesis that wolf (Canis lupus L., 1758) population reduction could reverse declines in a woodland caribou population following a BACI (before-after-control-impact) design conducted over a 12-year period in west-central Alberta, Canada. We monitored annual survival for 172 adult female caribou and calf recruitment from 2000 through 2012 and conducted a provincial government delivered wolf population reduction program annually during the winters of 2005–2006 to 2012 (inclusive) in an area centered on the Little Smoky range. Wolf removal translated to a 4.6% increase in mean population growth rate of the Little Smoky population mostly through improvements in calf recruitment. In contrast, the Red Rock Prairie Creek control population exhibited a 4.7% decline. Although the wolf population reduction program appeared to stabilize the Little Smoky population, it did not lead to population increase, however, with λ remaining approximately equal to 1. Therefore, we recommend, if required, predation management be combined with effective habitat conservation and long-term planning to effect the recovery of species, such as woodland caribou, which are declining as a result of habitat-mediated apparent competition.

scholarly journals Population Ecology of Caribou in British Columbia

Rangifer ◽  
1996 ◽  
Vol 16 (4) ◽  
pp. 73 ◽  
Author(s):  
D.R. Seip ◽  
D.B. Cichowski
Keyword(s):  
British Columbia ◽  
Canis Lupus ◽  
Rangifer Tarandus ◽  
Population Decline ◽  
Predation Rate ◽  
Mortality Rates ◽  
Geographic Range ◽  
Population Declines ◽  
Wolf Predation ◽  
Close Proximity

The abundance and geographic range of woodland caribou (Rangifer tarandus caribou) decreased in many areas of British Columbia during the 1900's. Recent studies have found that predation during the summer is the major cause of mortality and current population declines. Increased moose {Alecs alces) populations may be related to past and current caribou declines by sustaining greater numbers of wolves (Canis lupus). Mortality rates were greater in areas where caribou calved in forested habitats, in close proximity to predators and moose. Caribou populations which had calving sites in alpine areas, islands, and rugged mountains experienced lower mortality and were generally stable or increasing. A predator-induced population decline in one area appeared to stabilize at low caribou densities, suggesting that the wolf predation rate may be density dependent.

scholarly journals Habitat partitioning between woodland caribou and moose in Ontario: the potential role of shared prédation risk

Rangifer ◽  
1996 ◽  
Vol 16 (4) ◽  
pp. 81 ◽  
Author(s):  
H.G. Cumming ◽  
D.B. Beange ◽  
G. Lavoie
Keyword(s):  
Canis Lupus ◽  
Rangifer Tarandus ◽  
Potential Role ◽  
Real Life ◽  
Habitat Partitioning ◽  
Woodland Caribou ◽  
Northern Ontario ◽  
Gray Wolves ◽  
Direct Competition

This paper explores mechanisms of coexistence for woodland caribou (Rangifer tarandus caribou) and moose (Akes alces) preyed upon by gray wolves (Canis lupus) in northern Ontario. Autocorrelation analysis of winter track locations showed habitat partitioning by caribou and moose. Numbers of Delaunay link edges for moose-wolves did not differ significantly from what would be expected by random process, but those for caribou-wolves were significantly fewer. Thus, habitat partitioning provided implicit refuges that put greater distances between caribou and wolves, presumably decreasing predation on the caribou. Yet, direct competition cannot be ruled out; both apparent and direct competition may be involved in real-life situations. A synthesis including both explanations fits ecological theory, as well as current understanding about caribou ecology.

scholarly journals Population dynamics of the endangered mountain ecotype of woodland caribou (Rangifer tarandus caribou) in British Columbia, Canada

2020 ◽  
Author(s):  
Heiko Wittmer ◽  
BN McLellan ◽  
DR Seip ◽  
JA Young ◽  
TA Kinley ◽  
...  
Keyword(s):  
British Columbia ◽  
Population Dynamics ◽  
Rangifer Tarandus ◽  
Population Decline ◽  
Survival Rates ◽  
Adult Survival ◽  
Rangifer Tarandus Caribou ◽  
Vital Rates ◽  
Woodland Caribou ◽  
Annual Survival

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. © 2005 NRC Canada.

Woodland caribou: Facts for forest managers

1992 ◽  
Vol 68 (4) ◽  
pp. 481-491 ◽  
Author(s):  
H. G. Cumming
Keyword(s):  
Forest Management ◽  
Rangifer Tarandus ◽  
Population Decline ◽  
Habitat Destruction ◽  
Rangifer Tarandus Caribou ◽  
Woodland Caribou ◽  
Mortality Factors ◽  
Resource Managers ◽  
Ultimate Cause ◽  
Multiple Resource

A literature review points to predation as the proximate factor controlling woodland caribou (Rangifer tarandus caribou) populations in most cases, but that finding does not obviate the need for caribou to be included in forest management. Managers must consider the indirect effects of forest operations on caribou through their impacts on caribou mortality factors, such as prédation. Lichens remain important. Habitat destruction may in some cases be the ultimate cause of population decline. Reactions of caribou to disturbance vary, and remain controversial; more research is needed. Multiple resource managers of boreal commercial forests should identify sensitive components of caribou range – calving grounds, rutting locations, wintering areas, and travel routes among them – and prescribe for these areas in forest management plans. Ways of accommodating caribou in commercial forests are not well established, but some examples suggest how this might be done. Most importantly, areas that have been proven by their continued use to contain all necessary requirements for caribou survival should not be physically altered until their essential qualities and functions are better understood. Key words: Rangifer tarandus caribou, woodland caribou, predation, forest management.

scholarly journals Climate and management interact to explain the decline of woodland caribou (Rangifer tarandus caribou) in Jasper National Park

Rangifer ◽  
2012 ◽  
pp. 183-191 ◽  
Author(s):  
Mark Bradley ◽  
Lalenia Neufeld
Keyword(s):  
Climate Change ◽  
Wildlife Management ◽  
National Park ◽  
Rangifer Tarandus ◽  
Climate Data ◽  
Woodland Caribou ◽  
Predator Prey ◽  
Jasper National Park ◽  
Human Use

Woodland caribou in the southern portion of Jasper National Park have declined from an estimated 435 in the mid 1970s to a population estimate of 87 in the fall of 2009. We examined the available historical information to determine why caribou have declined. We compared three main hypotheses for caribou decline in JNP: human disturbance, climate change, and wildlife management. We used historical human use statistics, climate data, and animal abundance information to weigh the evidence for these competing hypotheses over two time scales. Caribou decline could not be attributed to changes in climate over the long-term, or an increase in human use (our proxy for disturbance). Caribou decline was attributed to a combination of climate and wildlife management. Recovery of caribou in Jasper National Park will likely be contingent on managing the interaction between the predator/prey dynamic and climate change.

scholarly journals Will ecosystem management supply woodland caribou habitat in northwestern Ontario?

Rangifer ◽  
1998 ◽  
Vol 18 (5) ◽  
pp. 25
Author(s):  
David L. Euler
Keyword(s):  
Ecosystem Management ◽  
Canis Lupus ◽  
Rangifer Tarandus ◽  
Natural Disturbance ◽  
Ecosystem Functions ◽  
Woodland Caribou ◽  
Managed Forest ◽  
Northwestern Ontario ◽  
And Function ◽  
Forested Ecosystems

Ecosystem management is emerging as an important concept in managing forests. Although the basic conceptual idea is not new, important defining principles are developing that elucidate some of the specific attributes of ecosystem management. These principles include: the maintenance of all ecosystems in the managed forest, rhe emulation of natural disturbance patterns on rhe landscape and the insurance that structure and function of forested ecosystems are conserved. Forest management has an impact on woodland caribou (Rangifer tarandus caribou), although the presence of wolves (Canis lupus) and moose (Alces alces) in the same northern ecosystems also affects the caribou-forestry interacrion. Specific management for caribou as a featured species has been proposed, based on managing large landscape blocks. Ecosystem management would also produce habitat in a manner that might accomplish the goal of conserving woodland caribou as well as maintaining other important ecosystem functions.

scholarly journals The role of predation in the decline and extirpation of woodland caribou

2020 ◽  
Author(s):  
Heiko Wittmer ◽  
ARE Sinclair ◽  
BN McLellan
Keyword(s):  
Rangifer Tarandus ◽  
Population Decline ◽  
Temporal Distribution ◽  
Pregnancy Rates ◽  
Foraging Habitat ◽  
Woodland Caribou ◽  
Instantaneous Rate ◽  
Population Growth Rates ◽  
Rate Of Increase ◽  
Winter Foraging

To select appropriate recovery strategies for endangered populations, we must understand the dynamics of small populations and distinguish between the possible causes that drive such populations to low numbers. It has been suggested that the pattern of population decline may be inversely density-dependent with population growth rates decreasing as populations become very small; however, empirical evidence of such accelerated declines at low densities is rare. Here we analyzed the pattern of decline of a threatened population of woodland caribou (Rangifer tarandus caribou) in British Columbia, Canada. Using information on the instantaneous rate of increase relative to caribou density in suitable winter foraging habitat, as well as on pregnancy rates and on causes and temporal distribution of mortalities from a sample of 349 radiocollared animals from 15 subpopulations, we tested 3 hypothesized causes of decline: (a) food regulation caused by loss of suitable winter foraging habitat, (b) predation-sensitive foraging caused by loss of suitable winter foraging habitat and (c) predation with caribou being secondary prey. Population sizes of caribou subpopulations ranged from <5 to >500 individuals. Our results showed that the rates of increase of these subpopulations varied from -0.1871 to 0.0496 with smaller subpopulations declining faster than larger subpopulations. Rates of increase were positively related to the density of caribou in suitable winter foraging habitat. Pregnancy rates averaged 92.4% ±2.24 and did not differ among subpopulations. In addition, we found predation to be the primary cause of mortality in 11 of 13 subpopulations with known causes of mortality and predation predominantly occurred during summer. These results are consistent with predictions that caribou subpopulations are declining as a consequence of increased predation. Recovery of these woodland caribou will thus require a multispecies perspective and an appreciation for the influence of inverse density dependence on population trajectories. © Springer-Verlag 2005.

Addendum to “Managing wolves (Canis lupus) to recover threatened woodland caribou (Rangifer tarandus caribou) in Alberta”

2015 ◽  
Vol 93 (3) ◽  
pp. 245-247 ◽  
Author(s):  
Dave Hervieux ◽  
Mark Hebblewhite ◽  
Dave Stepnisky ◽  
Michelle Bacon ◽  
Stan Boutin
Keyword(s):  
Canis Lupus ◽  
Rangifer Tarandus ◽  
Management Practices ◽  
Journal Editor ◽  
Species At Risk ◽  
Rangifer Tarandus Caribou ◽  
Woodland Caribou ◽  
Recovery Strategy ◽  
Effective Assessment ◽  
Independent University

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.

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