Population status, distribution, and movements of woodland caribou in west central Alberta

1988 ◽  
Vol 66 (4) ◽  
pp. 817-826 ◽  
Author(s):  
E. Janet Edmonds

Twenty-four woodland caribou (Rangifer tarandus caribou) in the mountains and foothills of west central Alberta were radio collared to obtain information on seasonal movements, location and extent of seasonal ranges, rutting and calving areas, and population status. The study was conducted from December 1979 to June 1984 (fall composition surveys continued to 1986). Two populations of woodland caribou resided in the foothills winter range: a migratory mountain variety that moved west to the mountains in spring and returned in fall, and a more sedentary woodland variety that remained year round in the forested foothills. Calving and rutting grounds of the two populations were widely separated (minimum of 60 km). The mountain population ranged over a much larger area (11 000 km2) than the woodland population (4000 km2). Woodland caribou were fewer (maximum estimate 50) than the mountain caribou (maximum estimate 200). Population sex–age structure of the mountain caribou population, based on six surveys during the rut (October), averaged 54 males: 100 females: 27 calves (15% calves). Annual minimum adult mortality was 22% for the mountain and woodland populations, and both populations appeared to be declining. Predation, primarily by wolves, was strongly implicated in adult mortality, but causes of calf mortality were not determined. Human-caused mortality was an additional factor. Intensive management is required to ensure the viability of these caribou populations in the face of increasing industrial and recreational development. A short-term wolf reduction program and long-term public education, law enforcement, and habitat protection programs are recommended.

2000 ◽  
Vol 78 (8) ◽  
pp. 1433-1440 ◽  
Author(s):  
Kirby G Smith ◽  
E Janet Ficht ◽  
David Hobson ◽  
Troy C Sorensen ◽  
David Hervieux

The responses of a herd of migratory woodland caribou (Rangifer tarandus caribou) to timber harvesting that fragmented about 11% of their winter range in west-central Alberta were examined in this study. From 1981 to 1996, 45 caribou were radio-collared and monitored during the initiation and completion of first-pass timber harvest (50% removal). Variables examined were home-range size, daily movement rates, and distance to the nearest cut block for radio-collared individuals. Daily movement rates and individual winter range sizes decreased as timber harvesting progressed. Caribou avoided using recently fragmented areas by an average of 1.2 km. If fragmentation of the winter range continues through timber harvesting and other industrial activities, the "spacing out" antipredator strategy used by caribou may be compromised. Based on these findings, timber-harvesting strategies are recommended that (i) ensure an adequate area of usable habitat to support the current population, (ii) minimize the amount of fragmented area, and (iii) in the short term avoid presently defined core use areas.


Rangifer ◽  
2007 ◽  
Vol 27 (4) ◽  
pp. 181 ◽  
Author(s):  
Rob Florkiewicz ◽  
Ramona Maraj ◽  
Troy Hegel ◽  
Marcus Waterreus

Carcross woodland caribou (Rangifer tarandus caribou) numbers are increasing as a result of an intensive management and recovery program initiated in 1993. In the last 13 years, three overlapping First Nation land claim agreements were settled resulting in a complicated array of private and public land management authorities on this winter range, situated in the Whitehorse periphery. Twelve years of VHF radio-collar data (1994-2005) and 5 years of GPS radio-collar data (2000-2005) for female caribou were assessed to determine winter concentration areas and important winter habitats. We contrasted locations from 11 GPS radio-collared caribou with land cover classes, derived from classified Landsat 7 imagery, to evaluate the distribution and abundance of preferred habitats within this winter range. We found significant use of Open Needle Leaf lichen vegetation classes and avoidance of the relatively more abundant Closed Needle Leaf class. Our resource selection function model validated the preference for Open Needle Leaf Lichen and determined that caribou were spaced significantly further from an estimate of the human Zone of Influence (ZOI) than was expected from random locations. While our assessment determined that 64% of the winter range was located outside of either private lands or land influenced by human activity, key winter vegetation classes were under-represented within this area. If caribou are to successfully recover on this landscape and persist through time it is essential to manage, through meaningful participation among land management authorities, the remaining caribou habitat for environmental rather than human consumptive values.


Rangifer ◽  
1996 ◽  
Vol 16 (4) ◽  
pp. 63 ◽  
Author(s):  
Richard Farnell ◽  
Norman Barichello ◽  
Katherina Egli ◽  
Gerry Kuzyk

Since the mid 1980's, the Aishihik herd of woodland caribou (Rangifer tarandus caribou) declined from approximately 1500 to 583 animals. During the same period a nearby herd, the Wolf Lake Herd increased from approximately 664 to 1249 animals. This paper compares aspects of the ecology of these two herds to determine how these relationships conform to a general model of caribou population ecology described by Seip (1992). Comparisons include caribou demographic characteristics and distribution patterns, predator densities, abundance of alternate prey, human hunting and snow depth on caribou winter range. Ecological differences between herds were apparent in the ratio of prime bulls to cows, the abundance of moose (Alces alces), the occurrence of coyotes (Canis latrans), late winter snow conditions, and access to hunting. We hypothesize that the Wolf Lake herd was able to grow because wolves {Canis lupus) preyed mainly on the relatively abundant moose population. A highly clumped winter caribou distribution may have further reduced the impact of wolf predation on the Wolf Lake herd. In contrast, the decline of the Aishihik herd was accompanied by a relative scarcity of moose, few prime aged caribou bulls probably due to a more liberal trophy harvest, and wider late-winter dispersion that offered wolves greater access to caribou. The decline may have been exaggerated by the peak in the snowshoe hare (Lepus americanus) cycle which may have temporarily improved wolf pup survival. We suspect that moose are normally the primary prey of wolves in the Yukon and that a decline in moose eventually results in their being too scarce to offer an economical prey choice, prompting a prey switch to caribou. Results of our analyses conform incompletely to Seip's (1992) model for woodland caribou population ecology, particularly because the Wolf Lake herd prospered where moose were relatively abundant.


Rangifer ◽  
1986 ◽  
Vol 6 (2) ◽  
pp. 43 ◽  
Author(s):  
W. K. Brown ◽  
J. Huot ◽  
P. Lamothe ◽  
S. Luttich ◽  
M. Paré ◽  
...  

<p>Recent studies of woodland caribou (Rangifer tarandus caribou) in northern Quebec and central Labrador have demonstrated similar patterns of seasonal movements and distribution among four herds. Aerial surveys and radio-telemetry indicated that animals occupied forest-wetland habitat at densities of 0.03 caribou km2, or lower, for most of the year. Although females were widely dispersed at calving individuals demonstrated fidelity toward specific calving locations, in successive years. Caribou did not form large post-calving aggregations. Movement was greatest in the spring, prior to calving, and in the fall, during or immediately after rutting. Caribou were generally sedentary during summer and winter, although some moved relatively long distances to late-winter range. Although the herds occupy continuous range across Quebec and Labrador, our data indicate that the herds are largely discreete and should be managed individually.</p>


Rangifer ◽  
2011 ◽  
pp. 103-118 ◽  
Author(s):  
Anne Hubbs ◽  
Piotr Weclaw ◽  
Michael Sullivan ◽  
Nicole McCutchen

Woodland caribou (Rangifer tarandus) are classified as threatened in Alberta. In support of Canada's Species at Risk Act, a Recovery Plan for Woodland Caribou in Alberta was completed in 2004 which required local implementation plans to be completed within 5 areas of the province. The West Central Alberta Caribou Landscape Plan (WCCLP) is the first of these to be initiated and it addresses the recovery strategies for 4 herds. Two aspatial computer models built on the STELLA© modelling platform (ISee Systems, 2007) were used to assist the planning team in evaluating cumulative effects and alternative scenarios for caribou conservation. The ALCES© (Forem Technologies 2008) modelling tool was used to forecast potential changes in the west central Alberta landscape over time. Yearly landscape condition outputs from ALCES© were then exported into a caribou-specific population model, REMUS© (Weclaw, 2004), that was used to project potential population responses by woodland caribou, other primary prey species [moose (Alces alces), elk (Cervus elaphus) and deer (Odocoileus sp.)] and wolves (Canis lupus) (Weclaw & Hudson, 2004). Simulated habitat management strategies that resulted in the highest likelihood of caribou recovery included the maintenance of a high proportion of old forest, the aggregation of industrial footprints and the reclamation of historic seismic lines (although the latter took decades to provide real dividends). Sharing of industrial roads, protection of fragments of old-growth, and expanding an already aggressive fire control strategy in Alberta had little additional effect on caribou recovery. Simulated population management strategies that were successful all involved decades of intensive wolf control, either directly or indirectly through intensive primary prey control (with the exception of woodland caribou) until old-growth forests recovered to densities that provided caribou habitat and decreased alternate prey of wolves. Although this modelling approach makes broad assumptions, it provides simple fundamental relationships that were useful in a multi-stakeholder team setting when evaluating the efficacy of different management strategies for the conservation of woodland caribou.


Rangifer ◽  
1996 ◽  
Vol 16 (4) ◽  
pp. 337 ◽  
Author(s):  
Donald C. Thomas ◽  
E. Janet Edmonds ◽  
W. Kent Brown

The diet of woodland caribou (Rangifer tarandus caribou) populations in the foothills and Rocky Mountains of west-central Alberta was estimated by microhistological analyses of feces collected in winter and summer. In winter, terrestrial lichens averaged 60-83% of fecal fragment densities in both areas. In the mountains, decreasing proportions of terrestrial lichens and increasing proportions of conifer needles and moss indicated decreasing accessibility of forage because of deeper/harder snow. Apparent diets in summer were dominated by Salix spp., sedges, and lichens. However, forb inflorescences and stems were largely undetected by the microhistological technique and results for summer samples must be interpreted accordingly. We conclude that the conservation and management of forest ecotypes of caribou must include options of lichen-rich habitats as a major component of management plans.


Rangifer ◽  
2011 ◽  
Vol 31 (2) ◽  
pp. 97 ◽  
Author(s):  
Kirkby G. Smith ◽  
Lois Pittaway

The Little Smoky woodland caribou (Rangifer tarandus) herd is a boreal ecotype located in west central Alberta, Canada. This herd has declined steadily over the past decade and is currently thought to number approximately 80 animals. Factors contributing to the herds' decline appear related to elevated predator-caused mortality rates resulting from industrial caused landscape change. At current rates of decline, the herd is at risk of extirpation. A calf survival enhancement project was initiated in the first half of 2006 as a means of enhancing recruitment while other longer-term approaches were implemented. A total of 10 pregnant females were captured in early March and held in captivity until all calves were at least 3 weeks old. Before release, calves were radiocollared with expandable drop-off collars. Following release, survival of mother and offspring were tracked at intervals until the fall rut. Survival of penned calves was compared to "wild-born" calves at heel of non captive radiocollared females. This approach is compared to other techniques designed to increase recruitment in caribou.


2008 ◽  
Vol 29 (2) ◽  
pp. 245-256 ◽  
Author(s):  
Carissa Jones ◽  
Isaac Rojas-González ◽  
Julio Lemos-Espinal ◽  
Jaime Zúñiga-Vega

Abstract There appears to be variation in life-history strategies even between populations of the same species. For ectothermic organisms such as lizards, it has been predicted that demographic and life-history traits should differ consistently between temperate and tropical populations. This study compares the demographic strategies of a temperate and a tropical population of the lizard Xenosaurus platyceps. Population growth rates in both types of environments indicated populations in numerical equilibrium. Of the two populations, we found that the temperate population experiences lower adult mortality. The relative importance (estimated as the relative contribution to population growth rate) of permanence and of the adult/reproductive size classes is higher in the temperate population. In contrast, the relative importance for average fitness of fecundity and growth is higher in the tropical population. These results are consistent with the theoretical frameworks about life-historical differences among tropical and temperate lizard populations.


1998 ◽  
Vol 76 (8) ◽  
pp. 1551-1569 ◽  
Author(s):  
A T Bergerud ◽  
J P Elliott

Caribou (Rangifer tarandus), elk (Cervus canadensis), moose (Alces alces), and Stone's sheep (Ovis dalli stonei) were either decreasing or stable in numbers in two areas in northeastern British Columbia in 1981-1982, prior to reductions in wolf (Canis lupus) numbers. Following the reduction of wolf numbers, recruitment improved 2-5 times for all four species, and all populations increased, based on either hunting statistics, census results, and (or) recruitments greater than 24 offspring at 9 months of age per 100 females. Recruitment of offspring at 9 months of age, when regressed against wolf numbers, declined with decelerating slopes for all four species. This inverse functional response is hypothesized to result from the preparturient spacing of females to reduce predation risk, and in this regard moose seem the least secure and sheep the most effectively spaced. For the four species, mean recruitment at 9 months of age that balanced adult mortality and provided a finite rate of increase of 1.00 was 24.16 ± 0.91 offspring/100 females (n = 11, coefficient of variation = 12.5%). The predicted recruitment rate for all four species in the absence of wolves was 53-57 offspring/100 females. But the birth rate of moose was much higher than those of the other species, indicating greater loss to other factors of which bear predation may be the greatest. Following wolf reductions of 60-86% of entire travelling packs, the wolves quickly recolonized the removal zones, with rates of increase ranging from 1.5 to 5.6.


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