Mama grizzly seen without cubs, then carcasses found in WY. What killed them?
A pair of yearling grizzly bear carcasses were found in a closed area of Grand Teton National Park, and both showed signs the bears had met a grim fate.
The carcasses were found about 750 feet apart — and showed signs that a larger bear had killed and eaten the yearlings, Grand Teton National Park said in a May 14 news release.
While patrolling the surrounding areas, including the Colter Bay developed area, Highway 89, Leeks Marina and AMK Ranch, law enforcement and wildlife officials noticed a lone adult grizzly with red ear tags, officials said.
“She was identified as GB1063, a bear who had frequently been observed in recent weeks with her yearling cubs,” officials said. “No cubs were observed with her during this sighting.”
The bear and her cubs had recently been spotted near developed and residential areas at Colter Bay, officials said. To decrease the chance of potential encounters between the bears and people, staff scared the family away when they lingered in the highly populated areas or near roads.
The mother bear and her three yearling cubs remained together during the hazings, officials said.
Wildlife officials determined it’s likely a male grizzly bear in the area “led to the separation of the yearlings” from their mom and that the male grizzly then killed and ate them, officials said. Officials aren’t sure what might have happened to the mama bear’s third yearling cub.
“Bears exhibit a range of fascinating behaviors influenced by their biological needs, social structures, and environmental factors,” said Grand Teton National Park bear biologist Justin Schwabedissen. “While it is incredibly sad to see a grizzly bear lose its cubs, depredation by other bears is a natural source of cub mortality in the Greater Yellowstone Ecosystem and has previously occurred in Grand Teton.”
Park staff are still monitoring the area and reminded visitors “to remain bear aware: carry bear spray, maintain a safe distance from all wildlife, and report any bear sightings to a park ranger.”
This story was originally published May 14, 2025 at 6:26 PM with the headline "Mama grizzly seen without cubs, then carcasses found in WY. What killed them?."
