Mother bears spend more time with cubs due to human hunting

Human hunting activity has helped shape bear evolution, according to a new study that looked at mother bear behavior as it relates to her cubs. Ordinarily, a female Scandinavian brown bear would spend about 1.5 years with her cubs, but hunting activity from humans has changed that. Researchers say a female Scandinavian brown bear now spends an average of 2.5 years with her cubs, but not for the reason you think.

One may be inclined to think the mother bear changes her behavior to stay with her cubs to help protect them from human hunters until they're larger, but that doesn't seem to be the case. Rather, single female bears are more likely to die than a mother bear with cubs due to restrictions on hunting bear family groups.

Mother bears that stay with their cubs longer are more likely to live because hunters are less likely to kill them. According to researchers, mother bears have been sticking around their cubs for steadily longer periods of time over the years. From 2005 to 2015, the rate of cub retention for longer durations increased from 7-percent to a much larger 36-percent.

However, individual bears don't change their strategies to compensate for human hunting; rather, hunters are killing off mother bears with the trait to spend less time with their cubs, leaving behind bears with behaviors that keep them with the cubs for longer durations. The researchers reveal that the trait itself is likely fixed.

Is this harmful to bears? Sort of. Because the mother bear spends more time with her cubs, she gives birth to less cubs overall during her lifetime. However, living a longer life may help compensate for the decrease in birth rate, addressing the potential problem.