Most black bears entered winter dens by the end of October, with most grizzly bears doing the same during the month of November. A small number of grizzly bears that have learned how to put on additional fat during early winter will remain out and about, for as much as another month.
All hibernating small mammals that were active in October, such as chipmunks, began hibernating.
Rough-legged hawks, which are often prominent on fence posts and power poles, returned from Arctic nesting grounds for the winter. Migrations of trumpeter and tundra swans brought higher numbers of swans to the valley.
Most deer and elk will migrations seem to be a little late this year because of the relatively mild weather and low snow levels during November.
Most pronghorn have left the Jackson Hole valley, bound for winter ranges south of Pinedale in the Green River Basin. Typically a few remain this time of year on the National Elk Refuge.
Adult bald eagles with nesting territories in the park remain year-round and will prey on higher numbers of waterfowl as fish become less available under ice.
Long-tailed weasels and snowshoe hares have recently turned from their brown summer coats to winter’s white pelage.
Beaver activity is strongly influenced by ice conditions as they continue to stash willow and other cuttings under the ice for a long winter’s food supply.
Wolf pups that have been largely confined to den and rendezvous sites since birth are now traveling with the rest of the pack throughout their home ranges, learning to hunt and how to survive in the wild.