Study: Cutthroat decline means grizzlies eat more elk

May 14, 2013

A new study shows that the decline in native cutthroat trout has had dramatic impacts on the migratory elk herds in the Greater Yellowstone Area. 

Lead Researcher Arthur Middleton and others were studying the decline of elk herds in the region, and they determined that grizzly bears were playing a greater role in those deaths than they realized. 

The illegal introduction of lake trout into Yellowstone Lake has harmed the cutthroat trout population. 

Middleton says what surprised him was the impact that decline had on the eating habits of Grizzlies.

“What this suggests is that when cutthroat trout are taken out of that equation that elk calves are a logical alternative and indeed it seems they are an alternative that Grizzly Bears have been turning to.” 

Middleton says the increase of wolves and grizzlies in the area also played a role, but he says the human influence on the cutthroat trout population has gone further than many had thought.