In a tragic turn of events at Grand Teton National Park, two of Grizzly 1063’s three yearling cubs were found dead, likely killed and partially consumed by a male grizzly bear. The cubs’ carcasses were discovered approximately 250 yards apart in a closed area south of Colter Bay on the morning of May 13, 2025. Both showed signs of depredation by a larger bear, according to the National Park Service (NPS) .
Grizzly 1063, a well-known sow in the park and believed to be the offspring of the famed bear 793 “Blondie,” had been observed with her three cubs earlier this spring. However, during patrols following the discovery of the carcasses, park staff observed her alone. The status of the third cub remains unknown .
Wildlife experts explain that such incidents, while distressing, are part of natural bear behavior. Male grizzlies may kill cubs that are not their own to bring the female back into estrus, increasing their chances of siring offspring. NPS bear biologist Justin Schwabedissen noted that depredation by other bears is a natural source of cub mortality in the Greater Yellowstone Ecosystem and has previously occurred in Grand Teton.
Wildlife photographer Jeff Plumb, who had been documenting Grizzly 1063 and her cubs, expressed his devastation over the loss. He recalled the cubs as healthy and playful, often wrestling and enjoying their surroundings. Plumb emphasized the emotional connection formed through observing and photographing the bears, making the loss particularly heartbreaking .
Park officials continue to monitor the area and urge visitors to remain vigilant, carry bear spray, maintain a safe distance from wildlife, and report any bear sightings to a park ranger. This incident serves as a somber reminder of the complex and sometimes harsh realities of wildlife behavior in natural ecosystems.
Source: Cowboy State Daily
