Ballard et al. (1994) organized park information on black bear (Ursus americanus) predation of caribou (Rangifer tarandus caribou) in North America. Overall, an estimated 16-30% of woodland caribou calves and 0-5% of adult woodland caribou fall victim to black bear predation. In this thread a summary of information is provided.
Figure 1. Adult black bear attacking caribou, near Voisey's Bay in spring, 1996 "...Two incidences of ungdate predation/scavenging by black bears were observed during 1996. The hrst incident occurred in April and involved an unrnarked adult male black bear attacking an adult caribou (Ran~ferander), which later died from its wounds and was eaten by the bear. This incident was photographed (Figure 1) by camp personnel (W. Montague, pers. comm.). The second incident occurred during an 2ttempt to dart a black bear fiom a helicopter on the Ikadlivik river in June 1996. The black bear was observed retrieving a dead moose calf (Alces alces) near the river bank, it then proceeded to run, approximately 50m, with the carcass in its mouth, then dropped the carcass and ran into the forest. An adult female moose was seen within 200 m of the carcass. The carcass was retrieved, and closer examination revealed that the calf had recently died and had been partially eaten. Other evidence of ungulate predation was found in a number of black bear scats. One scat contained 95% Cladonia sp., with intermittent bone shards. The remains of a dead caribou were found near the location of this scat, suggesting the bear had scavenged the caribou's stomach contents (Le., the source of the Cladonia). Approximately one dozen old bear scats composed of more than 90% caribou fur were..."