Habitat Use by Female Caribou: Tradeoffs Associated with Parturition
Barten NL, Bowyer RT, Jenkins KJ. 2001. Habitat Use by Female Caribou: Tradeoffs Associated with Parturition. The Journal of Wildlife Management. 65(1):77-92
We compared habitat use, forage characteristics, and group size among preparturient, parturient, and nonparturient female caribou (Rangifer tarandus) during and after the birthing season to test hypotheses involving acquisition of forage and risk of predation. We monitored 39 radiocollared females from the Mentasta caribou herd, Alaska, in 1994 and 40 animals in 1995. Group size of females giving birth at higher elevations was smaller (P 0.5). During peak parturition, females with young used sites with fewer predators (P < 0.05), a lower abundance of forage (P < 0.05), but with variable forage quality compared with those sites used by females without young. We hypothesized that parturient females used birth sites that lowered risk of predation, and traded-off forage abundance for increased safety. Nonetheless, few differences existed between parturient and nonparturient females in composition of diet or in indices of diet quality; we could not demonstrate a nutritional cost to maternal females from our analyses. We suggest that increasing population density might intensify intraspecific competition among females for birth sites, and thereby increase nutritional costs of using high-elevation areas with less forage but fewer predators.
- Type
- Journal Article
- Authors
- Barten, Neil; Bowyer, R; Jenkins, Kurt
- Units
- ARCN , BELA , CAKR , GAAR , KOVA , NOAT
- Keywords
- antipredator tactics, Arctic, Bighorn Sheep, calving success, Caribou, dalls sheep, Diet, forage abundance, forage quality, group size, Habitat Use, Mountain Sheep, Parturition, predation risk, Rangifer tarandus, seasonal changes, southern mule deer, statistical tests, tailed deer, tradeoffs