Bears as Predators ~

[brotherbear]

Yellowstone Bears in the Wild by James C. Halfpenny.


Lone bears and females with cubs do much of the predation on elk calves. The time when calves are most vulnerable coincides with the bear mating season, and adult males spend far more time searching for females than preying on elk calves.
Elk often act in defence during bear attacks on calves. A mother elk will approach a bear that is searching her area. If the bear chases the mother, the adult elk is seldom caught and the bear usually ends up starting a new search in a new area, presumably away from where the mother elk had hidden her calf.
In a chase, mother elk sometimes charge at the bear from the side, causing the bear to veer off and perhaps lose track of the calf it was chasing. At other times not only the calf's mother but other female elk will cross between a running calf and the pursuing bear. Occasionally famale will try to intimidate a bear and may actually kick at it. The final defense strategy is to flee into water, usually a river. This tactic works better with wolves than grizzlies.
Summer chases of adult elk are more often failure than successes. Much has been made about grizzlies killing large bull elk that are in a weakened condition after the autumn rutting season, but this has seldom been observed. Mattson calculates that on average a Yellowstone grizzly kills an adult elk once every year. Of course, some grizzlies kill no elk and other grizzlies kill more than one. Some of these elk must be bulls.
Some bears must prey on elk after dark. female bears with cubs may not come out of the forest until dark, but by morning light they are seen feeding on a freshly killed elk carcass. Reply