Unlike Canadian lynx, which they resemble, bobcats elsewhere have been highly adaptable to human-caused changes in environmental conditions; some biologists believe that there are more bobcats in the United States today than in colonial times. Yellowstone has many rock outcrops, canyons bordered by rock ledges, conifer forests, and semi-open areas that seem to offer conditions favorable for bobcats—adequate shelter, a variety of rodents, rabbits, hares, birds, and other small animals as well as seasonal carrion, for food. Carrion is seldom used if live prey is available. Studies elsewhere have shown that bobcats also may kill both young and adult antelope and deer; they stalk bedded adults and may be carried long distances while biting their prey in the neck. Bobcats live an average lifespan of about 7 years.