scholarly journals The late winter diets of barren-ground caribou in North-Central Canada

Rangifer ◽  
1986 ◽  
Vol 6 (2) ◽  
pp. 305 ◽  
Author(s):  
Donald C. Thomas ◽  
David P. Hervieux
Keyword(s):  
Rangifer Tarandus ◽  
Late Winter ◽  
North Central ◽  
Winter Range ◽  
Barren Ground ◽  
South Central ◽  
Conifer Needles ◽  
Central Canada ◽  
Winter Diets ◽  
Composite Samples

Rumen samples from 104 barren-ground caribou (Rangifer tarandus groenlandicus) collected in March 1980 and 1981 at 18 sites on the winter range in south-central Northwest Territories (NWT) and northern Saskatchewan were examined microscopically for relative occurrence of plant fragments. The composition of plant fragments in the rumens of calves did not differ from that in older caribou. Samples were homogeneous within sites and among them. Therefore we analyzed composite samples for each site and then pooled the data. Terricolous fruticose and foliose lichens averaged 68.5 ± 1.5% (SE) ot tallied fragments at all 18 sites, followed by conifer needles (11.9 ± 1.2%), green leaves of Vactinium spp., Ledum spp., and other shrubs and iorbs (5.6 ± 0.6%), twigs and bark (5.5 ± 0.4%), bryophytes (4.9 ± 0.6%) and 3.6% unidentified. The lichen component consisted of 8.4 ± 1.5% Stereocaulon spp., 46.9 ± 2.6% other fruticose lichens (largely Cladina spp., Cladonia spp., and Cetraria spp.), and 13.2 ± 1.5% foliose lichens (largely Peltigera spp.). A comparison of rumen contents with the average relative abundance of plants found in feeding craters at 13 sites suggests that use of plant species was not always proportionate to their occurrence.

scholarly journals Fire - caribou - winter range relationships in northern Canada

Rangifer ◽  
1996 ◽  
Vol 16 (2) ◽  
pp. 57 ◽  
Author(s):  
D.C. Thomas ◽  
S.J. Barry ◽  
G. Alaie
Keyword(s):  
Rangifer Tarandus ◽  
Fire Suppression ◽  
Age Classes ◽  
The West ◽  
North Central ◽  
Winter Range ◽  
Peak Biomass ◽  
Central Canada ◽  
Cladina Rangiferina ◽  
Terrestrial Lichen

We needed data on temporal changes in caribou forages after fire and relative use of age-classes of forests by caribou to help devise a fire suppression priority strategy for caribou winter range in north-central Canada. Consequently, from 1983 through 1986, we estimated the abundance of vegetation and relative use by caribou at 197 sites in western and eastern study areas on the winter range of the Beverly herd of caribou {Rangifer tarandus). Species of lichens attained peak biomass at different periods after fire - as early as 40-60 years for Cladonia spp. to > 150 years for Cladina rangiferina and Cetraria nivalis. Biomass of the primary "caribou lichen", Cladina mitis, increased rapidly from 21-30 years after fire to 41-50 years and attained maximum biomass at 81-90 yeats in the west and 41-60 years in the east. However, total lichen biomass increased with age of forest to 100-150 years because biomass of Stereocaulon spp. did not peak until after 100 years. The biomass of "caribou lichens" {Cladina spp. and Cetraria nivalis) stabilized after 61-80 years in the west and 41-60 years in the east. The biomass of terrestrial lichen species can be predicted from their cover. Caribou lichen abundance apparently was only one of several factors that caused caribou to use stands 151-250 years after fire more than othet age classes.

scholarly journals A life table for female barren-ground caribou in north-central Canada

Rangifer ◽  
1990 ◽  
Vol 10 (3) ◽  
pp. 177 ◽  
Author(s):  
Donald C. Thomas ◽  
Samuel J. Barry
Keyword(s):  
Life Table ◽  
Rangifer Tarandus ◽  
Sampling Error ◽  
Sampling Period ◽  
Cohort Size ◽  
North Central ◽  
Pooled Data ◽  
Barren Ground ◽  
Average Survival ◽  
Central Canada

A survivorship curve and cohort-specific life table were developed for female barren-ground caribou (Rangifer tarandus groenlandicus) sampled from the Beverly herd from 1980 through 1987. Significant (P~< 0.05)differences among yearly samples in the age distributions of females>2.5 years old were attributed to sampling error and real cohort size fluctuations caused by variations in productivity. Pooled data overcame much of that variation and the resultant quadratic-fit curve and life table are believed to yield about average survival/mortality statistics over the 8-year sampling period. Mortality rates increased progressively from 10.6% between age 2 and 3 years to 22.4% between age 10 and 11 years and accelerated thereafter.

Geographic variation in caribou on the Canadian arctic islands

1982 ◽  
Vol 60 (10) ◽  
pp. 2442-2454 ◽  
Author(s):  
D. C. Thomas ◽  
P. Everson
Keyword(s):  
Geographic Variation ◽  
Rangifer Tarandus ◽  
Canadian Arctic ◽  
The Other ◽  
Long Bones ◽  
Body Measurements ◽  
Morphological Similarity ◽  
North Central ◽  
Barren Ground ◽  
Northern Regions

Analyses of body, leg bone, skull, and pelage data indicated a cline in the characters of caribou (Rangifer tarandus) from central Boothia Peninsula to the western Queen Elizabeth Islands. The main difference between the skulls of barren-ground caribou (R. t. groenlandicus) on central Boothia Peninsula and the more northerly Peary caribou (R. t. pearyi) was a shorter muzzle in the latter. Pelage tone was markedly lighter in Peary caribou and they were smaller in most body measurements, most notably in the length of long bones. Two major populations of Peary caribou were identified: one on the western Queen Elizabeth Islands (Parry Islands), the other on Somerset and Prince of Wales islands. Differences in skull size and form suggest that each population was composed of two or more subpopulations. The larger and darker R. t. groenlandicus occurred on north-central Boothia Peninsula and the two subspecies and apparent intergrades were present in winter on northern regions of the peninsula. The morphological similarity of Peary caribou on Somerset and Prince of Wales islands is explained by interisland movements resulting in genetic mixing. The same is true for caribou on the western Queen Elizabeth Islands and that population apparently has little genetic interchange with the other.

scholarly journals Population ecology of two woodland caribou herds in the southern Yukon

Rangifer ◽  
1996 ◽  
Vol 16 (4) ◽  
pp. 63 ◽  
Author(s):  
Richard Farnell ◽  
Norman Barichello ◽  
Katherina Egli ◽  
Gerry Kuzyk
Keyword(s):  
Population Ecology ◽  
Rangifer Tarandus ◽  
Distribution Patterns ◽  
Late Winter ◽  
Woodland Caribou ◽  
Winter Range ◽  
Pup Survival ◽  
Moose Population ◽  
Snow Conditions ◽  
The Impact

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.

scholarly journals The distribution and movement patterns of four woodland caribou herds in Quebec and Labrador

Rangifer ◽  
1986 ◽  
Vol 6 (2) ◽  
pp. 43 ◽  
Author(s):  
W. K. Brown ◽  
J. Huot ◽  
P. Lamothe ◽  
S. Luttich ◽  
M. Paré ◽  
...  
Keyword(s):  
Rangifer Tarandus ◽  
Radio Telemetry ◽  
Late Winter ◽  
Rangifer Tarandus Caribou ◽  
Woodland Caribou ◽  
Seasonal Movements ◽  
Wetland Habitat ◽  
Winter Range ◽  
Aerial Surveys ◽  
Continuous Range

<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>

scholarly journals Prevalence of Echinococcus granulosus and Taenia hydatigena in caribou in north-central Canada

Rangifer ◽  
1996 ◽  
Vol 16 (4) ◽  
pp. 331 ◽  
Author(s):  
Donald C. Thomas
Keyword(s):  
Echinococcus Granulosus ◽  
Rangifer Tarandus ◽  
Infection Intensity ◽  
Parasite Prevalence ◽  
Predation Rate ◽  
Older Individuals ◽  
Taenia Hydatigena ◽  
North Central ◽  
Central Canada ◽  
Few Data

There are few data on the prevalence and infection intensity of parasites in large samples of caribou (Rangifer tarandus). Therefore, differences related to sex, age, and season are unknown. The effect of parasites on the health and condition of caribou also is poorly known. From 1980 through 1987, 1258 barren-ground caribou (R.t. groenlandicus) were collected from the Beverly herd in north-central Canada. The prevalence in lungs of cysts of the hydatid tapeworm (Echinococcus granulosus) increased significantly with age of caribou. Prevalence in females was 2% in the 2-5 year class and 8% in older individuals. Cysts were more prevalent in young females compared with young males. Reductions in physical condition and fecundity were not statistically significant. The prevalence of Taenia hydatigena cysts in livers increased significantly with age of host but not with sex and condition of the hosts. The use of parasite prevalence as an index of predation rate is discussed.

scholarly journals A fire suppression model for forested range of the Beverly and Qamanirjuaq herds of caribou

Rangifer ◽  
1996 ◽  
Vol 16 (4) ◽  
pp. 343
Author(s):  
Donald C. Thomas ◽  
The Beverly and Qamanirjuaq Caribou Management Board
Keyword(s):  
Rangifer Tarandus ◽  
Aboriginal People ◽  
Fire Suppression ◽  
Specific Area ◽  
Fire Cycle ◽  
Management Board ◽  
Winter Range ◽  
Natural Fires ◽  
Central Canada ◽  
Cycle Lengths

A fire suppression model was developed for forested winter range of the Beverly and Qamanirjuaq (formerly Kaminuriak) herds of barren-ground caribou (Rangifer tarandus groenlandicus) in north-central Canada. The model is a balance between total protection, as voiced by some aboriginal people, and a let-burn policy for natural fires advocated by some ecologists. Elements in the model were caribou ecology, lichen recovery after fire, burn history, community priorities for caribou hunting, and fire cycle lengths. The percent ratio of current productive caribou habitat to the goal for that habitat determines whether fire should be suppressed in a specific area. The goals for productive caribou habitat, defined as forests older than 50 years, were scaled by fire cycle length and community priority ranking. Thus, the model is an example of co-management: traditional knowledge combined with science in a joint forum, the Beverly and Qamanirjuaq Caribou Management Board.

scholarly journals Early fall and late winter diets of migratory caribou in northwest Alaska

Rangifer ◽  
2018 ◽  
Vol 38 (1) ◽  
pp. 27-38 ◽  
Author(s):  
Kyle Joly ◽  
Matthew D. Cameron
Keyword(s):  
Rangifer Tarandus ◽  
Physiological Stress ◽  
Late Summer ◽  
Late Winter ◽  
Winter Habitat ◽  
Pregnant Females ◽  
Winter Diet ◽  
Early Fall ◽  
Forage Type ◽  
Winter Diets

Lichens are the primary winter forage for large herds of migratory caribou (Rangifer tarandus). Caribou select for lichens more than they are available across the landscape and they generally avoid, during winter, habitat that has been burned by wildfires for decades while lichen abundance recovers. However, the relative importance of lichens in the diet is subject to debate. From 2010-2013, we conducted one of the largest microhistological studies of the early fall (58 samples from 1 site) and late winter (338 samples from 58 sites) diets of barren-ground caribou. Lichens con­stituted ~ 71% of the late winter diets of caribou in northwest Alaska, whereas moss (11%) and shrubs (9%) were the next most common forage items. Early fall diets were very similar to late winter, perhaps because deciduous vegetation is senescent during both periods. Diets of males, non-pregnant females and pregnant females were not significantly different. Pregnancy was not associated with the abundance of any forage type during winter but was associated with higher physiological stress. This result was expected as fall body condition dictates conception, caribou are ‘capital’ breeders, and gestation can be energetically demanding. Caribou that migrated south (i.e., wintered south of 67.1°N) had lower levels of nutritional stress, higher levels of lichen in the diet, and lower levels of moss and shrubs compared to caribou that did not migrate south. Future investigations into the potential connection between lichen abundance in the winter diet and survivorship, as well as linking the late summer diets of individuals to their reproductive success, should be undertaken.

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