It’s In Our Nature: Black bear population management successful in Pennsylvania
Another success story, at least here in Pennsylvania, is the growth of the black bear population.
My father was a hunter on his weekends off and I pestered him to tag along. I started hunting in 1965, and except for a day of small game hunting, my first real hunt was for bear.
I wasn’t very hopeful because in Carbon County then it was rather rare to see a bear, let alone think of harvesting one. But Dad, Wayne and I tried the Bethlehem watershed area in Penn Forest Township. We hunted close to Hell Hollow, one of the wild areas where bear hunters had some success. We actually saw a bear that day that crossed a fire line about a half-mile away. That was my first bear sighting.
The Pennsylvania Game Commission has done an excellent job managing them. They’ve had short seasons, a late season after sows have denned, and even closed the bear season a year or two to let the population recover. Today, the black bear population in Pennsylvania is about 18,000.
The bear population recovers slowly because a female bear only gives birth every other year. However, they often have a litter of two or three cubs.
Let’s discuss the bear’s breeding. Bears begin looking for mates in late June and from then, until early July, the males wander widely looking for potential mates. (This is when many bears are often seen in towns or even rather populous cities.) Since bears are not as numerous as deer, it can be a rather stressful time for the males, often eating less than normal and traveling far to find a receptive mate. Keep this info in mind as I continue.
I have two game (trail) cameras that I keep stocked with batteries all year long. This past summer, on July 2, a very large male bear was photographed mating with a much smaller female. Their gestation period is about 212 to 220 days. But why, with a gestation period only about 60 days less than humans, do the cubs only average 6 or 7 ounces at birth, while the average human baby weighs 7 pounds, 6 ounces?
The answer: Bears have delayed implantation. The female eggs, after being fertilized, and possibly by different males, quickly develop into a group of cells called a blastocyst. A blastocyst, however, remains dormant and doesn’t implant into the uterus until November. Biologists believe this is because if the sow in fall couldn’t find enough food to fatten up for the winter, the pregnancy would not continue. If she does “eat well” and stores up enough fat, the blastocyst implants in the uterus, and about mid-January the cubs are born. Cubs have eyes and ears closed and are completely helpless, with only wisps of fur on their pink bodies
Here is the question. Is a bear a true hibernator? Remember, animals that hibernate, like a woodchuck, see their respiration and heart rate slow to only a few a minute, they don’t defecate or urinate, and their body temperature drops to near freezing. Remember, the bear cubs are born in a den, probably within a week of this column’s printing in the coldest time of the year. Bear’s body temperatures drop very little. She must keep the cubs warm and nurse them almost constantly. She, too, remarkably doesn’t defecate or urinate. After about two or three months in the den, the cubs can now walk and are fully furred. But midsummer they are about 30 pounds. Just before the next summer’s mating time, the cubs are on their own.
I find so many amazing things in nature, and this is just another example.
Test Your Outdoor Knowledge: Do bears begin hibernation at the first snowfall?
Dec. 21 Trivia Answer: Skunks do not hibernate, but in very cold “stretches” like the recent ones, they will find a protected den (maybe under a storage shed in your backyard) and become dormant. They’ll curl up, try to conserve body heat, and fall into a stupor.
Email Barry Reed at breed71@gmail.com