Use of ungulates by Yellowstone grizzly bears Ursus arctos

摘要: Abstract Previous results of fecal analysis from the Yellowstone area and known abilities grizzly bears Ursus arctos to acquire digest tissue vertebrates suggested that grizzlies in this ecosystem obtained substantial energy ungulates. This issue was addressed using observations radio-marked bears, 1977–1992. Ungulates potentially contributed majority required for activity during non-denning season both adult female male grizzlies. Most (95%) estimated come largest-bodied ungulate species (elk Cervus elaphus, bison Bison bison, moose Alces alces), with greatest proportional contributions by scavenged (16%), calf yearling elk (10%) were killed (8%) or (8%). Grizzlies acquired 30% total edibles ungulates predation, which 13% (or 4% total) came predation on calves. scavenging occurred spring associated abundance relative availability different types carrion. Predation did not appear be compensatory. Rather, consumption varied inversely whitebark pine Pinus albicaulis seeds. The frequency increased density. Contrary previous suppositions, neither use nor study, despite large increases some populations. As expected identified trade-offs, seemed prey selectively upon moose, probably because their solitary habits forested surroundings, but otherwise favored vulnerable smaller-bodied such as No observed.