Pennsylvania's black bears should be denned-up with females giving birth to cubs

You’ve probably read or seen on TV about the Carbon county man that recently got attacked by a black bear. That’s an extremely rare occurrence but could have been prompted by rabies that it was subsequently tested for after it was shot by a neighbor. Another speculation is that it could have become humanized by residents feeding it either through bird feeders or uncovered garbage cans and it smelled food. This is also rare because black bears normally hibernate and den-up at this time of year. 

According to the Pennsylvania Game Commission, black bears in poor condition den for shorter periods than those in better shape. And on warm, winter days, they may emerge to look for food. 
Winter dens for male bears can be in a hollow tree, or log, an excavation resembling a large groundhog hole, beneath the root of a fallen tree, in a nest on top of the ground that would resemble a large bird nest, under a rock crevice and on occasion, beneath the deck of a residential home. Male bears den alone as do pregnant females who give birth to cubs there.  

Females typically prefer a more sheltered location such as a cave or deep rock crevice. Several years ago, I had the pleasure of accompanying renowned  PGC Bear Biologist Gary Alt, who held that position at that time, to check on a bear den site. Alt located the denned sow bear through a radio collar he had placed on her some time before. The sow was denned in a deep rock outcropping. After Alt used a jab stick to tranquilize it in the den, he and his assistant pulled the sow out to weigh it, take measurements and milk samples as it had cubs in the den. Interestingly and in subsequent testing, Alt said the sow’s milk had the consistency of sour cream, and it was rich in fats and protein. 

While it was a tight fit and I was a lot thinner back then, Alt allowed me to crawl into the den to photograph the two cubs that were in there. The pair had their eyes open and it sounded like they were bawling as their mom was gone. Cubs generally weigh 6-12 ounces and are 6-9 inches long. 

While the mother was outside the den, Alt removed the two cubs to weight and measure them. Then placed them back in. And before he and partner pushed and pulled the sow back in, Alt rubbed Vicks ointment on the sow’s nose so it wouldn’t readily detect human or an unknown scent on them. 

Females generally raise one litter every two years and the litters can range from 1-5 with three being the most common in Pennsylvania. Cubs will nurse in the den and will leave the den when they are three months old. They’ll typically den with their mothers for the first winter, then disband the following summer. 

While in their dens, be it males or females, the adults become dormant and lapse into and out of a deep sleep. Their body temperature is reduced as is their heart rate. They do not urinate or defecate while dormant. But as in the case of the Carbon County bear, it came out of wherever it was denned and attacked the pedestrian. 

Bears are extremely interesting animals and Alt documented his study results that he shared with game agencies in other states to benefit their black bear programs.  
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