Richard P. Smith
"Most Michigan black bears begin life in the normally dark to semi-dark interior of a den during January. Cubs average about 12 ounces in weight when born, but large ones may weigh as much as a pound. The newborns are basically hairless, with their eyes closed. The tiny bears' hair grows quickly after birth and their eyes open after about six weeks.
As many as five cubs may be born to an exceptionally healthy, adult female bear. One year I photographed a large female with five cubs on a Menominee County farm. Although females with five cubs aren't often seen, the birth of four cubs to Michigan females is not unusual. During the winter of 1994-'95, for example, Department of Natural Resources (DNR) wildlife biologists documented the presence of denned females with four cubs each in Alger, Dickinson and Menominee Counties In the Upper Peninsula (U.P.); Wexford and Montmorency Counties in the northern Lower Peninsula. The average number of cubs born to adult females is between two and three.
Winter may seem an odd time for such helpless creatures to be born and it is, compared to other mammals in the state, but it is something the animals are well adapted for. In spite of the harsh weather common during Michigan winters, most cubs manage to stay warm and thrive on a rich diet of milk provided by their mothers. The temperature inside maternal bear dens might be a little warmer than outside, but the mother bear is the real heater. Cubs stay warm by clinging to their mothers during the first weeks of life. As their hair grows, it provides enough insulation to help keep them warm, too."
To learn more unique aspects of the black bears' life history, their habits,