February 3, 2023

Do Black Bears Get “More Pregnant” If They Are Fatter?

A few days ago, the Bangor Daily News in Maine carried an opinion piece from a veterinarian about the upcoming probable referendum that would end bear hunting, trapping and hounding.

The resulting opinion piece generated some comments that readers can find by following this link.

Embedded in the comments was one from a John Glowa. Glowa is an animal rights pervert (my term of endearment) who seems to have an impulsive need to protect predators at any cost, including his agenda to bring introduced wolves into the Pine Tree State. Glowa’s comment stated:

Bears have what is called “delayed implantation” whereby the fetuses do not attach and grow until Fall when the pregnant female is fattening up for winter. The fatter the female, the greater the number of fetuses that will grow and the greater the likelihood that those fetuses will become cubs and that the mother and cubs will survive the winter.

It’s really unfortunate that a person calling others ignorant for not believing his narrative, can take scientific information, twist and distort it into a propaganda tool to promote a personal agenda.

Black bears do undergo what Glowa refers to as, “delayed implantation.” Essentially what that means is that the female bear, provided she is properly nourished (they breed every other year because of that), mates with a male bear in May and/or June in Maine. Shortly after copulation, an embryo forms and lays dormant within the bears reproductive system. It is after the bear enters hibernation, the the embryos attach themselves to the uterus and begin to grow.

To state that more bears will be born if a bear is fatter is actually a bit misleading and dishonest, especially when an agenda is at stake. Mr. Glowa states that the embryos will attach themselves, “when the pregnant female is fattening up for winter.” The attaching doesn’t really take place until after the fattening up process is complete.

It is actually unproven, Glowa’s statement, “The fatter the female, the greater the number of fetuses that will grow.” In actuality, historically female bears average around 2 cubs. In Maine that average might be slightly higher. At the time of conception (springtime) the number of embryos that will determine how many cubs might be born and survive, is determined then and not after the bear is fattened up.

Scientific studies and observations have determined that female bears, with embryos in them from breeding, need to have enough stored fat cells for the embryos to attach. Embryos will not multiply at the time of attachment, but the number could be reduced or not attach at all.

Obviously, the intent of the comment was to convince readers that fat bears produce more bears and the way it was worded, in the context of the referred-to opinion piece, the comments are actually quite dishonest. But that is to be expected in the upcoming emotion-laced debate over hunting bears. Expected, yes, but it shouldn’t be accepted, as lying and misleading are wrong.

In addition, Glowa’s and others are concerned that baiting bears is what is creating more bears. The anti hunting crowd wants you to think that the baiting program, “feeds many tons of food to thousands of bears every fall.” Although I believe this is a bit of an exaggeration, the number of bears being effected over a short period of time, is not having negative or positive effects on the health condition of the bear. The act is a management tool to keep numbers of bears in check, thus providing a healthier bear population. It’s difficult to argue with that.

And here’s a thought to consider. The antis argue that bear are becoming habituated to human food and activity. If that were the case then one logically would expect that with each passing year that bear hunters put out their bait, the bears would be lined up and waiting. However, that’s not the case. Talk to any bear hunter who baits and they will tell you that the activity at their bait sites is mostly determined by the availability of natural food.