Nature (PBS) – The wilds of Yellowstone National Park are a world of predators, scavengers and opportunists. In this vast and complex kingdom, two dominant predators reign supreme: the grizzly bear and the wolf. Size and power square off against speed and teamwork, as mighty grizzly bears contend with powerful packs of wolves for control of the food supply. Though these two fearsome hunters would normally rule their ranges uncontested, in Yellowstone they must share resources, or face starvation.
A grey wolf with patches of fur stained with blood stands hunched down and snarling at a massive brown bear that has seemingly just killed the wolf’s companion. The bear hovers over the dead wolf’s body in the picture, as it appears to have already begun lifting itself onto its hind legs, presumably to lunge/swat at the aggressive wolf with his large clawed forepaws ethanology.tumblr.com/post/4424325283/image-a-grey-wolf-with-patches-of-fur-stained
Gray Wolves, Canis lupus, Killed by Cougars, Puma concolor, and a Grizzly Bear, Ursus arctos, in Montana, Alberta, and Wyoming MICHAEL D. JIMENEZ 1, VALPAJ. ASHER 2, CARITABERGMAN 3 , EDWARDE. BANGS 4 , and SUSANNAHP. WOODRUFF 1 1U.S. Fish and Wildlife Service, P.O. Box 2645, Jackson, Wyoming 83001 USA 2Turner Endangered Species Fund, 1875 Gateway South, Gallatin, Montana 59730 USA 3 Fish and Wildlife Division, Alberta Sustainable Resource Development, Box 1420, Pincher Creek, Alberta T0K 1W0 Canada 4U.S. Fish and Wildlife Service, 585 Shepard Way, Helena, Montana 59601 USA Jimenez, Michael D., Valpa J. Asher, Carita Bergman, Edward E. Bangs, and Susannah P. Woodruff. 2008. Gray Wolves, Canis lupus, killed by Cougars, Puma concolor, and a Grizzly Bear, Ursus arctos, in Montana, Alberta, and Wyoming. Canadian Field Naturalist 122(1): 76-78 "...Wolves and bears normally avoid each other; however, Wolves killed Black Bears in Alberta and Minnesota (Rogers and Mech 1981; Horejsi et al. 1984) and consumed denning Black Bears in Manitoba (Paquet and Carbyn 1986). Aggressive interactions between bears and Wolves are often associated with bears usurping ungulate carcasses from Wolves (Murie 1944; Ballard 1980; MacNulty et al. 2001; Ballard et al. 2003; Smith 2005) and defending young (Joslin 1966; Hayes et al. 1992; Ballard et al. 2003). A Brown [Grizzly] Bear killed a Wolf after usurping the carcass of a Moose (Alces alces) killed by Wolves in Alaska (Ballard 1980). We report the first recorded incident of a Grizzly Bear killing a Wolf in the western United States. In summer 2005, we monitored a Wolf pack consisting of four adults and four pups, near Jackson, Wyoming. We placed an Argos satellite collar on a two-year-old Wolf and collected location data 4-24 times per day. Two clusters were less than a mile apart, indicating that Wolves had been there for 48 hours. We discovered the carcass of a yearling Moose at the first cluster. At the second cluster we found the fresh carcass of a 20-22 kg female Wolf pup that had been dead approximately one day. Along the back of the Wolf were large punctures through the hide, extensive muscle tissue damage, and massive hemorrhaging on the inside of the hide. The spine was broken in several places. Fresh Grizzly Bear tracks were found at the Moose carcass and the Wolf pup carcass. Based on the presence of Grizzly Bear tracks and the injuries to the Wolf pup, we concluded the Grizzly Bear killed the Wolf pup. After extensive literature review, Ballard et al. (2003) summarized that Wolves, Cougars, and Grizzly Bears are occasionally adversaries due to interference competition; however, exploitation competition be -tween wolves and other large predators did not result in significant resource partitioning. Wolf mortality from Cougar and Grizzly Bear predation is rare, and therefore it does not appear to be a significant factor impacting Wolves at the population level..."
Male grizzly bear sleeping on/ defending a bison carcass in Lamar Valley, Yellowstone National Park.
"...Reports of another bison carcass in Lamar Valley garnered our attention. Observers reported a grizzly bear and five more wolves around the carcass so we packed up and moved on. By the time we arrived, the wolves were nowhere to be found. The male grizzly bear, however, was sleeping on top of the carcass. Fall is the time of hyperphagia (over-eating) for bears and an adult grizzly bear may consume upwards of 20,000 calories a day. It’s worthwhile for a bear to defend its food until it’s consumed its fill..." reefstorockies.com/2013/09/26/day-1-with-the-junction-butte-wolf-pack-yellowstone-national-park/