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.

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.

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 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 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 Age-specific fecundity of the Beverly herd of barren-ground caribou

Rangifer ◽  
1990 ◽  
Vol 10 (3) ◽  
pp. 257 ◽  
Author(s):  
Donald C. Thomas ◽  
Samuel J. Barry
Keyword(s):  
Rangifer Tarandus ◽  
Barren Ground ◽  
Rangifer Tarandus Groenlandicus

The age-specific fecundity of the Beverly herd of barren-ground caribou (Rangifer tarandus groenlandicus) was monitored each winter from 1979-80 through 1986-87. Fecundity in 840 females increased with age from 12% in yearlings to 86% at age 5 years and it did not decline in old (> 11 yr) females. Significant variations occurred among winters and even between two subherds in one winter. Reproductive abnormalities were detected in 2 of 840 females and a probable resorption in 1 of 420 females collected in March. Only about 5% of the fetuses were conceived late, possibly by repeat ovulators. Combining survival and fecundity data yielded age-specific calf production, which indicated that, for example, 54% of calves were born to females 3-6 years old.

scholarly journals Growth rates and morphological measurements of Porcupine caribou calves

Rangifer ◽  
1989 ◽  
Vol 9 (1) ◽  
pp. 9 ◽  
Author(s):  
Katherine L. Parker
Keyword(s):  
Surface Area ◽  
Growth Rates ◽  
Rangifer Tarandus ◽  
Type I ◽  
Feeding Regime ◽  
Barren Ground ◽  
Body Weights ◽  
In The Wild

<p>Body weights, leg lengths, and surface area were monitored for bottle-raised barren-ground caribou calves (Rangifer tarandus granti) from the Porcupine herd up to 1 year of age. Body weights were compared with maternally-raised calves from the same cohort in the wild and from the Delta herd. A successful feeding regime for bottle-raising caribou calves is presented.</p><p>Veksthastigheter og morfologiske m&aring;l hos Porcupine karibu-kalver.</p><p>Abstract in Norwegian / Sammendrag: Kroppsvekter, visse knokkel-lengder og kropps-overflate areal ble m&aring;lt hos flaske-oppf&oslash;dde kalver av barren-ground karibu (Rangifer tarandus granti) fra Porcupine-stammen opp til 1 &aring;rs alder. Kroppsvekter ble sammelignet med normalt oppf&oslash;dde kalver av samme type i det fri og fra Delta-stam-men. Det presenteres et vellykket system for flaske-oppforing av karibu-kalver.</p><p>Porcupine-lauman karibuvasojen kasvunopeus ja morfologiset mitat.</p><p>Abstract in Finnish / Yhteenveto: Porcupine -lauman pulloruokinnalla olleiden tundrakaribuvasojen ruumiinpainot, jalanpituu-det ja ruumiin pinta-alat mitattiin 1 vuoden ik&auml;&auml;&auml;n saakka. Ruumiinpainoja verrattiin vastaaviin luonnon-oloissa kasvaneisiin saman lauman ja Delta -lauman vasoihin. Tutkimus kuvaa toimivan vasojen pulloruo-kintamenetelm&auml;n.</p>

Humoral immunity and output of first-stage larvae of Elaphostrongylus rangiferi (Nematoda, Metastrongyloidea) by infected reindeer, Rangifer tarandus tarandus

1984 ◽  
Vol 58 (1) ◽  
pp. 13-18 ◽  
Author(s):  
G. Gaudernack ◽  
O. Halvoresen ◽  
A. Skorping ◽  
K. A. Stokkan
Keyword(s):  
Antibody Titre ◽  
Humoral Immunity ◽  
Specific Antibody ◽  
Rangifer Tarandus ◽  
Sampling Period ◽  
Immunofluorescence Technique ◽  
Rangifer Tarandus Tarandus ◽  
Indirect Immunofluorescence Technique ◽  
Elaphostrongylus Rangiferi ◽  
Inverse Pattern

AbstractThe use of an indirect immunofluorescence technique demonstrated that serum from reindeer, Rangifer tarandus tarandus, infected with Elaphostrongylus rangiferi (Nematoda, Metastrongyloidea) contained antibodies directed against antigen(s) on the cuticle of the parasites first-stage larvae (LI). Output of LI from the male reindeer was low in the period June to August, but increased to a higher level during the rutting season (September to October). The titre of specific antibody showed an inverse pattern. In the female reindeer, larval output remained high throughout the sampling period from January to July. During this period antibody titre was low. A relationship between stress (rutting season or calving period), immunity and larval output is suggested.

Morphology of the barren-ground caribou ovary

1978 ◽  
Vol 56 (8) ◽  
pp. 1684-1696 ◽  
Author(s):  
T. Charles Dauphiné Jr.
Keyword(s):  
Connective Tissue ◽  
Rangifer Tarandus ◽  
Corpora Lutea ◽  
Seasonal Incidence ◽  
Histological Techniques ◽  
Northern Canada ◽  
Ovary Weight ◽  
Barren Ground ◽  
Ovarian Stroma ◽  
Rangifer Tarandus Groenlandicus

Reproductive tracts were collected from 532 female caribou (Rangifer tarandus groenlandicus) in northern Canada over a [Formula: see text]-year period. Ovaries were weighed and scrutinized by gross and histological techniques. Ovaries of nulliparous and nongravid, parous cows responded to follicular fluctuations by increasing in weight in summer and declining in winter. Weights of ovaries from calves, yearlings, and 2 year olds overlapped extensively. Formation of corpora lutea of pregnancy more than doubled ovary weight. During gestation ovary weight declined and then partially recovered; it increased with age in pregnant cows. The number and size of follicles [Formula: see text] diameter increased with age until puberty, reaching greatest development just before the autumn rut. After puberty the seasonal incidence of such follicles remained stable except during gestation, when it declined. Corpora lutea of pregnancy regressed to form apparently permanent scars composed of vascular and connective tissue remnants. Secondary corpora lutea developed in 35% of the cows at or before conception and upon regression produced scars which were not permanent. Regressing corpora lutea of estrus also disappeared into the ovarian stroma, apparently within 1 year. In individual cows one ovary, selected at random, dominated in the production of ova and corpora lutea.

Effects of weather and parasitic insects on behavior and group dynamics of caribou of the Delta Herd, Alaska

1997 ◽  
Vol 75 (10) ◽  
pp. 1659-1670 ◽  
Author(s):  
Frank M. Mörschel ◽  
David R. Klein
Keyword(s):  
High Temperature ◽  
Ambient Temperature ◽  
Group Dynamics ◽  
Rangifer Tarandus ◽  
High Ambient Temperature ◽  
Alaska Range ◽  
North Central ◽  
Insect Abundance ◽  
Rates Of Change ◽  
The North

The influence of weather and parasitic insects on the behavior and group dynamics of caribou (Rangifer tarandus) of the Delta Herd in the north-central Alaska Range was investigated. Data on weather, insect abundance, and caribou behavior were collected during summer in 1994 and 1995. High ambient temperature had the greatest influence on activity budgets and rates of change in activity of caribou. In the insect season, rates of activity changes and standing increased and feeding decreased with high temperature. Rates of activity changes and moving increased and feeding decreased with high temperature, even in the absence of insects. Caribou decreased feeding and increased standing in the presence of oestrid flies, and increased the rate of activity changes in the presence of mosquitoes and oestrid flies. Weather, especially high temperature, and parasitic insects, particularly oestrid flies, affected caribou mainly by decreasing foraging opportunities and increasing energy-expending activities.

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