In a remarkable and unprecedented event, a Yellowstone tour guide recently witnessed and filmed a female grizzly bear (Ursus arctos horribilis) with five cubs, a sight never recorded in Yellowstone National Park. Grizzly bears typically give birth to two cubs per litter, with larger litters of up to four being uncommon but not extraordinary. However, the appearance of a five-cub litter is an exceptional rarity, setting a new record for the park’s documented history from 1959 to the present. National Park Service spokeswoman Linda Veress highlighted the significance of this observation, emphasizing the historical novelty of such a large litter in Yellowstone. The video, captured by tour guide Andrea Baratte, provides valuable documentation of this extraordinary moment, ensuring its authenticity and contributing to the ongoing study of grizzly bear reproductive behaviors.

The sighting has captivated nature enthusiasts and researchers, prompting discussions about the possible origins of this unique family. Nature photographer Stan Mills also managed to capture footage of the bear family, showing the mother bear keeping a watchful eye on her cubs as they frolicked nearby. Frank van Manen, a biologist with the U.S. Geological Survey’s Interagency Grizzly Bear Study Team, noted that while five-cub litters have been documented in Alaska, this is a first for Yellowstone. Van Manen suggests the possibility of the mother bear adopting cubs from another litter, which is not uncommon among grizzlies. Regardless of their origin, the mother bear faces a challenging task ahead, as she must care for and protect her cubs, with only about half of grizzly cubs surviving their first year. This extraordinary observation offers a rare glimpse into the complexities of grizzly bear family dynamics and the unpredictable wonders of nature.