U of A study shows grizzly cubs learn bad behaviour from moms
Grizzly bears getting into conflict with landowners in southwestern Alberta appear to be learning the bad behaviour from their mothers, according to a new study.
The research from the University of Alberta, which was published Wednesday in the scientific journal PLOS ONE, studied 2,043 grizzly bears in Montana, Alberta and British Columbia.
“We built a family tree,” said Andrea Morehouse, principal investigator and post-doctoral student at the U of A.
“In Alberta, specifically ... we were focusing on this idea of how bears were acquiring problem behaviour, because in our field work in Alberta we had targeted sites where grizzly bears were causing problems ... they had gotten into grain or killed livestock.”
Morehouse spent several years tracking the bear population in southwestern Alberta by gathering hair samples for DNA to determine the population and come up with ways to change their status as a threatened species in the province.
She found there are 67 resident grizzly bears in the area — a four per cent increase since 2007 — and dozens of other bears passing through the area from Montana or B.C.
The results didn’t come as a surprise to ranchers in southern Alberta, who have been noticing an increase in conflicts with grizzly bears.
In the latest study, Morehouse worked with researchers at the U.S. Geological Survey.
There were 213 individual grizzly bears in her Alberta data set, which were studied for problem behaviours and whether their parents were involved in conflicts. “We were looking at whether this conflict behaviour was inherited,” she explained.
“If that were the case, we expected to see a significant relationship between a father’s behaviour and the offspring.
“If it were socially learned, we expected more offspring to show conflict behaviour if their mother had been a problem bear, and no relationship for the paternal conflict behaviour because, in grizzly bears, the males aren’t involved in rearing.”
They found a significant relationship between the mother bears and their cubs. “If your mom was a non-problem female, the offspring were also likely to be non-problem bears,” she said. “If the mom was a problem individual, a higher proportion of her offspring were also involved in problem behaviours.”
Bear biologists have long thought that cubs learn behaviour from their mothers.
“We had a pretty unique opportunity with this large data set to test that hypothesis, so that was pretty cool,” said Morehouse.
“Now we have direct evidence that supports social learning in bears.”
She said the results offer an important message for biologists, wildlife managers and the public.
“One of the big take-home messages is the importance of proactive work,” said Morehouse. “If we can try to prevent some of these behaviours from developing in the first place, there’s then not an opportunity for it to be learned by the cubs.”
Strategies being used in southern Alberta include installing electric fencing, managing bear attractants and raising public awareness.
“These are programs that are already going on in Alberta and Montana,” she said. “This really speaks to the importance of them and ensuring that type of work continues.”