Caribou Calf Mortality in Denali National Park, Alaska
Adams LG, Singer FJ, Dale BW. 1995. Caribou Calf Mortality in Denali National Park, Alaska. The Journal of Wildlife Management. 59(3):584-594
Calf mortality is a major component of caribou population dynamics, but little is known about the timing or causes of calf losses, or of characteristics that predispose calves to mortality. During 1984-87, we radiocollared 226 calves in the Denali Caribou Herd, an unhunted population utilized by a natural complement of predators, to determine the extent, timing, and causes of calf mortality and to evaluate influences of year, sex, birthdate, and birth mass on those losses. Overall, 39% of radio-collared calves died as neonates, and 98% of those deaths were attributed to predation. Most neonatal deaths occurred within 8 days of birth. Few deaths occurred after the neonatal period (5, 10, and 0% of calves instrumented died during 16-30, 31-15-, and >150 days of age, respectively). Survival of neonates was lower in 1985, following a severe winter, than during the other 3 years. In years other than 1985, calves born during the peak of calving (approx 50% of the total, born 5-8 days after calving onset) experienced higher (P 10 days old. Wolf predation was not related to calf age and peaked 10 days after onset of calving. Grizzly bear and wolf predation on neonates during the calving season was a limiting factor for the Denali Caribou Herd.
- Type
- Journal Article
- Authors
- Adams, Layne; Singer, Francis; Dale, Bruce
- Units
- CAKN , DENA
- Keywords
- Alaska, Animal Studies, calf, Canis lupus, Caribou, Denali Caribou Herd, Grizzly Bears, herd case-history, IAR, Mortality, neonatal mortality, Population Dynamics, Predation, Predator-Prey Relationships, Rangifer tarandus, Survival, Ursus arctos, Wolf, Wolf predation