The Jackson elk herd may be forgetting how to migrate from the National Elk Refuge in Jackson, Wyoming to Yellowstone National Park.
If this persists, wildlife biologists fear, Jackson elk may forget how to migrate entirely, which could foreshadow future changes to the Yellowstone elk herd.
According to Wyoming Public Media, the number of elk who make the trip between the National Elk Refuge and Yellowstone has declined from nearly 30 percent in the 1970s to only two percent today. Elk Refuge biologist Eric Cole told WPM the main reason for this decline in elk migration rests in calf mortality. Namely, fewer elk calves are surviving to remember the corridor. From WPM:
Cole said elk calves aren’t born knowing migration routes. They have to learn them from their mothers.
“It’s not individual elk deciding their going to change where they migrate to,” he said. “What’s happening is the percentage of calves that survive to adulthood is much lower for these Yellowstone migrants compared to the short distance migrants.”
Cole said the shorter migrations from Wilson to Moose have more calves surviving to learn those routes. He said there are a couple possible reasons for that.
“It is true that there is higher predator density in southern Yellowstone than we see in the areas where the short distance migrants summer,” said Cole. “Another alternative explanation is forage quality could potentially be better. We don’t know. We have to explore that further.”
Cole adds that the possibility of elk forgetting the Jackson-Yellowstone corridor is part of a worrying trend globe wide, as more migration corridors are forgotten due to changes in animal behavior.
Elk migration in the Greater Yellowstone Area has gotten much attention in the past few years, most notably from researchers Arthur Middleton and Joe Riis, whose work was highlighted in an exhibit at the Buffalo Bill Historical Center of the West. Entitled “Invisible Boundaries: Exploring Yellowstone’s Great Animal Migration” covered several Yellowstone animal migrations, but elk were a big focus.