JACKSON, Wyo. — Following the news of grizzly bear 399’s death in a vehicle collision on Tuesday, Oct. 22, many were concerned for the fate of 399’s yearling offspring.
Known to some as Spirit, the yearling is believed to have been born in winter 2023. Grizzly bears remain dependent on their mothers for their first two years of life; if 399 had survived a few weeks longer, she and the yearling would have hibernated together one last time. Team Leader of the Interagency Grizzly Bear Study Team Dr. Frank T. van Manen says the yearling has a strong chance of enduring winter, even without a parent.
“This yearling is probably well-positioned for survival,” van Manen told Buckrail in a phone interview on Friday, Oct. 25.
Van Manen noted that 399’s ability to provide food for her offspring helped to set them up for success.
“Grizzly 399 was a really good mom,” van Manen said. “Her cubs were always on the heavier side. By the end of the first year, they typically had gained maybe more than average body mass compared to other offspring of the same age. In that regard, this yearling probably has a little bit of an advantage compared to the average yearling at this point in time.”
The yearling appears to have built up plenty of body mass and fat reserves to prepare for winter, according to van Manen. As far as the young bear’s ability to successfully hibernate goes, van Manen expressed confidence that the yearling’s “strong innate behaviors” could lead it to select a suitable den site.
Van Manen noted that his team had observed other scenarios in which yearling cubs had been separated from their mothers. In a study comparing yearlings who were translocated with their mothers (sometimes for human-bear conflicts) versus yearlings whose mothers were translocated away from them, van Manen said the short-term survival likelihood was comparable for both groups.
The data bodes well for 399’s yearling, so long as it steers clear of roadways and human developments.
“This is a sad story, of course, but if there’s a little bit of silver lining, it’s the fact that this yearling, in my mind, has a pretty good chance of making it,” van Manen said. “The one thing that is probably gonna be the most challenging is where it’s at. It’s the same challenge that 399 and her previous offspring had to deal with. The yearling is in a landscape with a lot of human activity and access to human food that could get it in trouble.”
Van Manen added that the same study of yearling grizzlies indicated that male yearlings could be more susceptible to get into human-bear conflicts, especially those involving unsecured attractants like garbage and pet food.
“You really can’t blame the bear when there’s easy access,” van Manen said.
Let this serve as a reminder to secure all bear attractants, even as winter weather approaches.
