The annual aerial survey of the herd conducted during December 2010 resulted in a count of 4,635 elk, down 24 percent from the 6,070 reported the previous year. There has been about a 70 percent drop in the size of the northern elk herd from the 16,791 elk counted in 1995 and the start of wolf restoration to Yellowstone National Park.
Predation by wolves and grizzly bears is cited as the major reason for the decline in elk numbers, according to the Northern Yellowstone Cooperative Wildlife Working Group, made up of resource managers and biologists from the Montana Fish, Wildlife, & Parks, National Park Service (Yellowstone National Park), U.S. Forest Service (Gallatin National Forest), and U.S. Geological Survey-Northern Rocky Mountain Science Center in Bozeman. Wolves in northern Yellowstone prey primarily on elk. Also, predation on newborn elk calves by grizzly bears may limit the elk population’s ability to recover from these losses.
Drought conditions experienced during the early 2000s appear to have impacted the nutrition and abundance of forage, and may have lowered reproduction rates in some elk.
The number of permits issued for the antlerless Gardiner Late Elk Hunt declined from 1,102 in 2005 to just 100 permits during the 2006-2010 seasons. The late-season hunt was eliminated altogether for 2011.
The number of grizzly bears seen on the northern range during elk calving season has decreased slightly in recent years. Also, the wolf population on the northern range inside Yellowstone National Park has dropped from 94 wolves in 2007 to 37 wolves in 2010. Biologists suspect predator numbers may be responding somewhat to the decline in the elk population.
Biologists expect the reduction in the number of wolves and the elimination of the late season hunt will result in some increase in the elk population.
The Northern Yellowstone Cooperative Wildlife Working Group will continue to monitor trends of the northern Yellowstone elk population and evaluate the relative contribution of various components of mortality, including predation, environmental factors, and hunting.
Photo by Wallace Dayton, courtesy of National Park Service.
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