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Williams,
T.M. and D.C. Heard. 1990. Bathurst and Beverly caribou herd spring
classification counts, February and March 1984. 28 pp.
ABSTRACT
From
early January to mid-February 1984 large numbers of Bathurst and Beverly
barren caribou (Rangifer tarandus groenlandicus) occupied winter
range north of McLeod Bay, Great Slave lake.
By 7 groups of breeding cows, probably from both herds, had
migrated northeast out of the trees to form a large aggregation in the
area of Walmsley and Fletcher lakes.
After 7 March, the rate of migration slowed and the aggregation
dispersed. Classifications were conducted from 27 February to 28 March,
1984. We
classified 12,456 caribou in 28 groups.
The group size was 445 + 132 (X + S.E.) and ranged
from 20 to 3022.
Of 10,469 caribou 1 year old or older (1+) 13.6% were male and
86.4% were female giving 16 males:100 1+ females.
From the ratio of 22 + 2.0 (R + S.E.) calves:100 1+
females and assuming an initial calf production of 69 calves per 100
females (Parker 1972) and 1+ female survival from June 1983 of 93%, 29%
of calves born in June 1983 were alive in March 1984.
Overwinter calf survival was poor relative to the 1978-1983 mean.
After incorporating the unrepresented male segments of the
Bathurst and Beverly herds, we estimated that calves 12% of the
populations, a recruitment rate into the 1+ populations of 14%.
We observed 0.7 wolves per hour of reconnaissance flown.
As Bathurst and Beverly cows were in relatively good physical
condition over the winter of 1983-84, low
calf:l+ female ratios may reflect relatively high wolf predation on
Bathurst and/or Beverly caribou, or may be an artefact of sampling
biases that arose when calves, yearlings and males segregated out of
bands of migrating cows, which reached the barrens in late February and
early March 1984.
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