CHEYENNE, Wyo. – The number of wolves in Yellowstone National Park declined by 27 percent last year, but wildlife officials said Monday that the drop isn’t unusual.
The National Park Service counted 124 wolves inside Yellowstone in 2008, down from 171 wolves in 2007. A similar population decline occurred in 2005, when overall wolf numbers in Yellowstone dropped 31 percent.
Glenn Plumb, chief of wildlife management in Yellowstone, said population swings among wildlife are a natural occurrence.
“I anticipate over the long term that the numbers will go up and the numbers will go down,” Plumb said.
He said the wolves lost last year likely died from killing each other and possibly from disease. Biologists will be working to determine if there was a disease outbreak, he said.
Gray wolves were reintroduced into Yellowstone beginning in 1995. They have become a tourist attraction in the park, and they have also spread to areas outside Yellowstone, causing conflicts with domestic livestock.
Federal wildlife biologists have attempted to remove federal protections for gray wolves outside the park and turn over their management to the states of Wyoming, Montana and Idaho. But environmentalists have challenged those attempts, saying the state management plans did not adequately ensure sustainable populations of wolves.
Hunting is one of the tools each state wants to use as a way of controlling the number of wolves that take up residence outside Yellowstone and other national parks and wilderness areas. There are an estimated 1,500 wolves in the three states.
“Using Yellowstone as an example in terms of the number of wolves that have died from disease or from wolves killing other wolves, we’re just very worried about management plans that will manage for the minimum, as natural causes can lead to population declines quite easily,” said Melanie Stein, the Sierra Club’s associate regional representative.
As for the Yellowstone wolves, Plumb said the greatest decline in numbers last year occurred on the park’s northern range where the greatest wolf population density exists. The northern range population dropped 40 percent, from 94 to 56 wolves.
The decline in the wolf population in the interior of the park was smaller, dropping from 77 to 68, or down 11 percent from the previous year.