The Associated Press | Posted: Wednesday, February 27, 2008 12:00 am
YELLOWSTONE NATIONAL PARK - The elk population in the northern end of Yellowstone National Park continues to decline slightly and the animals appear to be gradually moving north of the park, biologists said.
Winter range north of the park is at a lower elevation and tends to have less snow, better forage availability and milder temperatures compared to winter ranges within the park.
"Elk may be using several factors, including the presence of wolves, in selecting where they spend the critical winter months," said Tom Lemke, a biologist with Montana Fish, Wildlife and Parks.
If that trend continues, the importance of the area north of the park as prime elk habitat will only increase, he said.
Wildlife biologists counted nearly 6,300 elk in an aerial survey earlier this month, compared to 6,738 in 2007 and 6,588 in 2006. The numbers are well below the 1994 record high of 19,000 elk and the 9,545 counted in 2005.
"This decrease likely reflects the continuing effects of predation by wolves and other large carnivores and possibly some effects from the severe, long-term drought," Yellowstone biologist P.J. White said in a statement Tuesday.
Montana's state elk management plan calls for about 3,000 to 5,000 elk north of Yellowstone, with 2,000 to 3,000 wintering on or near the state-owned Dome Mountain Wildlife Management Area. In the past six years, an estimated 3,200-4,000 elk have wintered north of the park with 2,100-3,000 elk in the Dome Mountain area.
However, biologists said reproductive rates in the herd remain below desired levels, so state wildlife officials have dramatically reduced the number of antlerless elk that can be hunting in the area in recent years.
"Hunting has basically been removed as a significant factor regulating northern Yellowstone elk numbers," Lemke said.
A 2003 study into why so many elk calves weren't making it to adulthood determined that bears were responsible for more than half the calves killed by predators. Wolves killed about 12 percent and coyotes got about 11 percent.