Grizzly Bear "Supermom" Spotted In Yellowstone With Five Cubs For First Time

Parents in the animal kingdom often have their work cut out for them, from octopus moms who can’t eat while looking after their eggs, to those animals going it solo. What is unusual is large mammals having multiple offspring, but that is exactly what’s happened in Yellowstone National Park as a grizzly bear female was spotted with an extremely rare five cubs.

Grizzly bears ( Ursus arctos horribilis ) are one of two species that live within Yellowstone, the other being the black bear ( Ursus americanus ). Bear cubs are usually born in January or February and typically in pairs though some litters can be up to four. This makes this litter of five even more unusual. In fact, it seems this is the first time a litter that large has ever been reported in the park.

Andrea Baratte, a tour guide at Yellowstone who managed to film the cubs , told Cowboy State Daily he’d never heard of a litter of five before. “I’m so glad that I got to document it, otherwise nobody would have believed it,” he said.

Nature photographer Stan Mills also filmed the cubs. “These grizzlies were walking toward the right when I came over a little mound and spotted them,” Mills wrote in a caption in the video below (the bears can be seen at 2:23). “The mother spotted me while I was getting my camera out.”

There is the question of whether the cubs all belong to the one bear mother or some have been adopted from another litter. In 2011, mother and daughter adult bears each gave birth to two and three cubs, respectively. The third cub originally belonging to the daughter was later adopted by the older bear. In 2016, a Katmai brown bear adopted a yearling cub in addition to her own 9-month-old after its mother died. Grizzly bear mothers have been known to abandon their cubs, possibly due to fear of humans or human contact .

“If this was truly a litter of five, it would be the first one recorded in the history of the Greater Yellowstone Ecosystem, for sure,” said Frank van Manen, who leads the Interagency Grizzly Bear Study Team, in a statement in WyoFile .

Without genetic testing, we won’t know if the current Yellowstone supermom is biologically related to each of her offspring.

“Five cubs in a litter are the most we have ever observed in the park, at least from 1959 to present — the period of the park's history we have good records for,” National Park Service spokeswoman Linda Veress told Cowboy State Daily.