Early caribou calf mortality in northwestern British Columbia
Date
1985
Authors
Page, Richard Edward
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Abstract
Thirty four newborn caribou calves were collared with mortality sensing radios in two study areas in Northwestern British Columbia . In 1979 , calves suffered 60% mortality in the first month and 80% to 4 months. In 1980, mortality rates were 20% in the first month and 50% to 4 months. Wolf and grizzly bear predation were the primary mortality factors. The difference between years was hypothesized to be due to snow melt patterns that restricted the distribution of calving females in 1979 and increased predation rates. A minimum of 35 % survival to the fall is necessary to balance adult mortality. Survey data indicated that excess predation on calves has been frequent over the last decade, leading to a decline in total number of caribou in the region.