Species: Rangifer tarandus

Gregarious; in tundra, usually in bands of 10-50 or loose herds of about 1,000. Sexes may segregate seasonally. May form herds after fawning (not in southeastern Manitoba). Tundra caribou may travel extensively in summer in attempt to avoid bothersome insects (Fancy et al. 1989). <br><br>Often incurs high calf loss, mostly due to predation (Bergerud et al. 1984). In south-central Alaska, Bergerud and Ballard (1988) concluded that wolf predation limited caribou recruitment, though winter starvation was proposed as the important population control by another researcher. <br><br>In northeastern Alaska and adjacent Canada, first-year survival of calves was 51%; mean annual survival rate was 84% for adult females and 83% for adult males; hunting mortality for the herd averaged 2-3% annually (Fancy et al. 1994). <br><br>In Quebec, home range size of adult females averaged 148 sq km and did not vary seasonally or annually (Ouellet et al. 1996). <br><br>White-tailed deer carry and disperse into the environment meningeal worms that usually are fatal to moose and caribou but are clinically benign in deer; hence, white-tailed deer, through worm-mediated impacts, commonly are believed to exclude moose and caribou from areas where deer occur (see Schmitz and Nudds 1994).