Black Bears - Polar Bears & Wolves

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Some of the material detailing relations between Polar Bears/Black Bears & Wolves are found in the Bear Mortality and Wolves thread. While some of the material overlap, IMO another separate thread was needed.


North American Black Bears & Wolves Interspecific Relations: In comparison to the grizzly bear, there are fewer wolf/bear observations made because the two bears live in different habitats: grizzly or brown bears are found in open areas while the American black bear live in dense closed canopy type areas. Unlike its cousin the grizzly bear, the opposite relationship exist between black bears and wolves where packs of wolves enjoy the position of strength and dominate.

In 81% of wolf-black bears encounters, wolves outnumbered bears. Wolves won 69 % of interactions while black bears won 15%. Young black bears were involved in 35% of encounters; a rate much higher than found in young grizzly bears.


Mortality: Of the twenty-six recorded interactions between black bears and wolves; nine times resulted in black bear fatality. Six of the nine bear moralities involved wolves seeking out black bears in their dens. Single bear moralities occurred at a feeding site, near a wolf den, and at an unclassified site. There are two records of wolves killing adult black bears Ursus americanus (Rogers and Mech 1981; Paquet and Carbyn 1986). In both instances, the wolves were in packs. Rogers (1987) reported that nine wolves killed a female bear and her cub in a den.

In an example of asymmetrical interference competition, a black bear displaced a single wolf from its kill in northeastern Alberta. The black bears of northeastern Alberta are found to be one of the more predatory populations of black bears.



North American Polar Bear & Wolf Interaction: Polar bear and wolf contact are rare occurrences. One recorded interaction details the death and consumption of a cub by a pack of wolves during the bear's spring migration. Other meetings were observed near a caribou kill site adjacent to the bear's den and another one where wolves attacked a sow polar bear and her cubs; in both situations there was no report of mortality. Negligible impact result in polar bear/wolf interactions.





Literature

Ballard, B. Warren, Carbyn, N. Ludwig, and Smith, W. Douglass. Wolf Interactions with Non prey. In: Wolves: behavior, ecology and conservation. Boitani L, editors. The University of Chicago Press; Chicago, IL: 2003. pp. 259–271.

Fremmerlid, A. Mark, Latham, M. David. (2011). LoneWolf, Canis lupus, Displaced from a Kill by an Adult Black Bear, Ursus americanus, in Northeastern Alberta. Can. Field Nat. 123:266—267.

Paquet, P.C., and L.N. Carbyn. 1986. Wolves, Canis lupus, killing denning black bears, Ursus americanus, in the Riding Mountain National Park area. Can. Field Nat. 100:371—372.

Ramsay, MA, and Stirling, I. (1984). Interactions of wolves and polar bears in northern Manitoba. J. Mammal. 65: 693 -694.

Rogers, L. L., and L. D. Mech. 1981. Interaction of wolves and black bears in northeastern Minnesota. Journal of Mammalogy 62:434–436.

Rogers, L. 1987. Effects of food supply and kinship on social behavior, movements, and population growth of black bears in northeastern Minnesota. Wildl. Monogr. 97. 72 pp.

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Mortality: Of the twenty-six recorded interactions between black bears and wolves; nine times resulted in black bear fatality. Six of the nine bear moralities involved wolves seeking out black bears in their dens. Single bear moralities occurred at a feeding site, near a wolf den, and at an unclassified site. There are two records of wolves killing adult black bears Ursus americanus (Rogers and Mech 1981; Paquet and Carbyn 1986). In both instances, the wolves were in packs. Rogers (1987) reported that nine wolves killed a female bear and her cub in a den.

For those of you interested, Paquet and Carbyn provide the following victim details. Victim one remains include a askull from a small bear, an intact front leg with an attached scapula with partially consumed remains of the body found on a heavily trafficked wolf trail. The sex of the bear was not determined. The proximity to the den suggest the bear was killed in its den and dragged out but poor snow/ground conditions made accurate verification difficult. The second black bear victim was not dis-articulated but most of its flesh was consumed. The bear was estimated to be 11 years old. Subsequent examination of the bear skull revealed the bear had been shot in the face below the left orbit but to what degree the bear was disabled is not clear. Author speculation suggest the bear was shot prior to denning (Fall period). Another black bear (third victim) carcass was found by a trapper on February 17, 1984. The size of the skull showed the bear to be young no more than three years old. The disturbed plant material/debris indicate the wolves dug three holes into the bear den chamber. The bear emerged 15 m before it was killed. The study period for all three black bears spans the first three weeks of February, 1984.



Paquet, P.C., and L.N. Carbyn. 1986. Wolves, Canis lupus, killing denning black bears, Ursus americanus, in the Riding Mountain National Park area. Can. Field Nat. 100:371—372.

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Wolf (Canis lupus) Predation of a Polar Bear (Ursus maritimus) Cub on the Sea Ice off Northwestern Banks Island, Northwest Territories, Canada

E.S. RICHARDSON1,2 and D. ANDRIASHEK1
(Received 31 October 2005; accepted in revised form 15 January 2006)

ABSTRACT. We describe the apparent predation of a polar bear (Ursus maritimus) cub by wolves (Canis lupus) on the sea ice
just off the northwest coast of Banks Island, Northwest Territories, Canada. On 20 April 2004, while following the tracks of a female bear and two cubs-of-the-year in the snow during a helicopter survey, we noted that the bear tracks had been joined by several sets of wolf tracks. After following both sets of tracks for about 1 km, we observed a disturbed area in the snow with
numerous overlying tracks. Upon landing and searching the site, we found the remains of a polar bear cub that the wolves had
successfully separated from its mother and killed. This is only the second documented observation ever made of a polar bear killed by wolves.
pubs.aina.ucalgary.ca/arctic/Arctic59-3-322.pdf

So far all polar bear/wolf relationships which are rare only involve the death of cubs.