Will 27-Year-Old Grizzly 399 Have More Cubs? It’s Possible, Biologist Says

Grizzly 399 has apparently yet to emerge from her den this year. And it’s not known whether the 27-year-old sow will have cubs this year, although it's possible.

Mark Heinz

April 02, 20233 min read

Grizzly 399 an her last group of cups
Grizzly 399 an her last group of cups (File Photo Courtesy Sam Bland)

With Wyoming is still getting sledgehammered by a hard winter, grizzly bears are apparently sleeping in and the most famous of them all, Teton Parks Grizzly 399, is no exception.

The last confirmed sighting of Grizzly 399 was in September, when she was busy fattening up for hibernation, Jack Bayles of Team 399 told Cowboy State Daily. 

"There's still lots of snow on the ground (and) no one that we know has seen her," Bayles said, although two other grizzlies have been spotted so far this year in Teton Park. 

Team 399 has for years taken photos and video of the famed grizzly, helping her reach worldwide celebrity status. She's known to be unusually comfortable around crowds and has frequently taken her cubs to areas near roadways in and adjacent to Teton Park.

Grizzly 399 and her young brood of four cubs in 2020.
Grizzly 399 and her young brood of four cubs in 2020. (Cowboy State Daily Staff)

Did She Go Into Hibernation Pregnant?

"Whether she'll have cubs to show off if and when she emerges this year isn't yet known," said Bayles and Wyoming Game and Fish Department Large Carnivore Specialist Dan Thompson.

"Whether the 27-year-old sow will have cubs again is the billion dollar question the world is waiting to have answered," Thompson told Cowboy State Daily. 

There are suggestions of her being bred, or at least courted, by a male last summer the unfortunate advantage of being constantly being watched, he said. 

However, Grizzly 399 is 27 years old, an advanced age for bruins, which rarely live to see 30 in the wild. 

We have documented a few bears having litters at the age of 25 in the GYE (Greater Yellowstone Ecosystem), so it's possible, Thompson added. 

Grizzly 399's most recent litter was a rare set of quadruplets born in 2020. Those cubs had all gone off on their own by early last summer. 

In July 2022, Game and Fish wardens killed one of them after it was reported that the juvenile grizzly had repeatedly caused trouble in some residential areas. The killing drew widespread criticism. 

As Long As Her Teeth Hold Out  

"Grizzly 399 tends to stay in her den longer when she has cubs, particularly newborns," Bayles said. 

"With yearling and 2-year-olds, she is usually out by mid-April," he said. "With cubs-of-the-year, it is usually around five weeks later that she emerges." 

"Grizzlies health and longevity hinges largely upon the condition of their teeth," Thompson told Cowboy State Daily previously. Bears that lose their teeth can no longer eat particularly high-protein springtime fare such as big game winter kill carcasses, so they starve. 

If her teeth are still intact, Grizzly 399 should have a veritable smorgasbord of carcasses to gorge on when she does emerge. There has been unprecedented big game winter die-off this year. 

As of late last summer, her teeth appeared to be in great shape for a bear her age, although Game and Fish has no plans to clean them to possibly prolong her life, Thompson said that the time. 

Grizzlies Hitting Snooze Button

Deep snow, much of it freezing up nearly as hard as concrete, has contributed greatly to the suffering and death of elk, deer and antelope. 

And the sheer nastiness of the winter might be keeping grizzlies in their dens longer than usual, Thompson said. 

"Usually, March is a busy month for bear activity, but it wasn't this year," he said. So, it's expected more bears will start popping up later this month. 

"For now, the first bear spotted out this year in Yellowstone in early March, and a few others that have emerged since, will mostly have the place to themselves," Thompson said. 

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Mark Heinz

Outdoors Reporter