The behavior of brown bears in Sweden has been changing in response to changes in rules concerning the hunting. Basically, you can’t take a mother with cubs. The result?
“Generally, the cubs have followed their mother for a year and a half,” says Professor Jon Swenson from the Norwegian University of Life Sciences (NMBU). “Only rarely have we observed them to follow her for two and a half years.”
This has now changed. Today, more cubs stay with their mothers an additional year, as opposed to 15 to 20 years ago. “Man is now an evolutionary force in the lives of the bears,” Swenson says. …
As long as a female has cubs, she is safe. This hunting pressure has resulted in a change in the proportion of females that keep their cubs for 1.5 years in relation to those that keep them for 2.5 years. In the period from 2005 to 2015, the number of females keeping their cubs for an additional year has increased from 7% to 36%. The individuals themselves do not alter their strategies. They portray either one behavior or the other, and this trait seems fixed.
“This basically means that we are shooting more of those females that only keep their cubs for a year.” [Phys.org]
Since the individuals are not altering their behavior, it suggests a genetic change, although it could still be a learned behavior, passed to following generations.
I suppose a genetic study would be necessary to verify it. It’s fascinating to think the genetics could change this fast.
