Deer 255 reaches the end of her journey

Deer 255, a mule deer known for its annual 250-mile migration from southwest Wyoming to central Idaho, has died. According to researchers with the Wyoming Migration Initiative, who announced her death this morning, her GPS collar data indicates she died around noon on April 11 in Wyoming’s Red Desert, just three days after her spring migration. The physical evidence suggests she was killed by a predator, most likely a mountain lion.

Credit: Courtesy of Ian Freeman/Wyoming Migration Initiative

When she was ten years and ten months old, Deer 255 had spent years jumping fences, crossing highways and dodging predators in search of nutritious food for herself and her fawns. To the many people who followed her travels, she exemplified the extraordinary endurance – and vulnerability – of the deer, pronghorn and elk that sustain themselves and their herds by migrating hundreds of miles each year. As Christine Peterson wrote in our April issue:

Deer 255 is fat and elusive and, according to researchers, can become irascible with her fawns, urging them to keep moving with body language familiar to the parents of Homo sapiens. During her travels, she crosses lands managed by the National Park Service, the US Forest Service, the Bureau of Land Management and the State of Wyoming, not to mention countless private properties and busy roads…

Between 2019 and 2022, four animated videos of her annual 240-mile migration from southwest Wyoming to central Idaho — the longest one-way mule deer migration ever recorded — were viewed nearly four million times online. Her collar number became synonymous with marathon performance.

Deer 255’s herd mates are currently completing their spring migration; many will spend the summer south of Grand Teton National Park in Wyoming. Their migration routes, like those of most other migratory mammals, still await permanent protection.

This story is part of Hooglandnieuws’ Conservation beyond limits project, which is supported by the BAND Foundation.

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