Yellowstone Grizzlies Blamed For Elk Decline?Yellowstone News, Bear Hunting Magazine
Two studies released recently suggested that the elk decline in and around the Yellowstone National Park area may be connected to a drop in cutthroat trout in the area. And apparently, it might be the bears fault. Because of fewer spawning trout in the area, grizzlies have had to change their diet from less fish to more meat, that meat coming from elk calves.
Because of this, many believe that the change in diet has significantly impacted the elk population in the area. Bears in Yellowstone have always been the largest predators of elk calves, but now researchers are seeing a spike in the number of elk killed. Calf recruitment has gone down by 4-16% and overall, elk growth decreased by 2-11%.
Although, they did state that they do not believe this is the entire answer to where many of the elk calves went, but believe it is worth thinking discussing.
One study tracked 27 collared grizzly and black bears in Yellowstone and found a large decrease of between 70-95% of trout eaten by bears for the last several years. Instead they have turned to elk calves, killing one between every two-eight days. The void left by the absence of trout is sizable and the bears are trying their best to rely on the elk, but it is not enough.
Studies show that the primary reasons for the drop in cutthroat trout is competition caused by lake trout, drought and occasionally, disease. A small group of grizzlies studied in the park could eat more than 12,400 pounds of cutthroat trout during spawning season.