We examined selection of ants as food by black bears (Ursus americanus) in Utah by comparing the genera of ants we sampled from study plots in 5 vegetation types with those found in bear scats. In the plots we found 641 ant colonies representing 18 genera. Five genera comprised 85% of all colonies sampled: Formica, Lasius, Camponotus, Tapinoma, and Myrmica. Thirteen genera were found in scats, but 99% were composed of the same 5 listed above. Limited utilization of some ant genera by black bears may reflect body size, colony size, nest type, and presence or absence of a functional sting. Fifty-three percent of all ant colonies in sample plots were found under rocks. Energy values of ants ranged from 4.9 to 6.2 cal · g−1 dry weight. Pupae of Formica and Camponotus contained slightly more fat than respective workers, but the relationship was reversed for Lasius. Pupal cases were found in 33% of the scats, and bears may prefer ant brood because they are more digestible than adults and lack mechanisms of defense. Ants are a predictable and ubiquitous food source for black bears.
Auger, Janene; Ogborn, Gary L.; Pritchett, Clyde L.; and Black, Hal L.
"Selection of ants by the American black bear (Ursus americanus),"
Western North American Naturalist: Vol. 64
, Article 3.
Available at: http://scholarsarchive.byu.edu/wnan/vol64/iss2/3