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Williams,
T.M. 1990. Results of the 1985 spring classification counts on the
Bathurst barren-ground caribou herd. 26 pp.
ABSTRACT
Relatively
few caribou (Rangifer tarandus groenlandicus) occupied
taiga areas of Bathurst winter range in 1984/85.
An aerial reconnaissance survey from 9 to 24 April 1985 located
small scattered groups mainly of males in the taiga, a dense aggregation
mainly of cows occupying a band running north along the tree line from
Rocknest Lake, and a lower density band in the taiga running west from
Rocknest lake to the Calder River.
An unknown number of caribou that wintered north of McLeod Bay,
Great Slave Take, had moved northeast onto the barrens by mid-January.
By mid-April large bands mainly of breeding cows were migrating
rapidly northeast from Rocknest Lake towards the calving grounds
east of Bathurst Inlet. 1539 caribou were classified from three groups
between 17 and 20 April 1985.
Mean group size was 513 + 218 (X+S.E.) and ranged from 240
to 1046.
Of 1191 animals 1-year-old or older (1+), 19% were rnale, giving
a sex ratio of 24 1+ males: 100 1+ females.
Calf survival from June 1984 to April 1985 was 48%; greater than
the survival rate (42%) calculated for the Beverly herd from 1978 to
1984. After
incorporating the unrepresented male segment, Bathurst calves comprised
18% of that population, a recruitment rate into the 1+ population of
22%.
No
wolves were observed in 49.5 hours of reconnaissance, suggesting low
wolf abundance in association with taiga wintering bands of caribou.
The segregation of calves, males and yearling from bands of
breeding cows prior to spring migration masks real changes in calf: 1+
female ratios and confounds overwinter mortality estimates. More
intensive winter range reconnaissance and/or the placement of radio
collars on Bathurst cows would increase the efficiency of classification
surveys by decreasing the amount of reconnaissance required to locate
aggregations prior to and during spring migration, and by providing a to
estimate the proportion of tundra wintering animals.
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