An aerial survey conducted in February shows the elk population in northern Yellowstone is down from last year.

The Northern Yellowstone Cooperative Wildlife Working Group conducted this annual survey on Feb. 18 using three airplanes and staff from the Montana Department of Fish, Wildlife and Parks and the National Park Service.

Staff counted 3,915 elk, including 915 elk inside Yellowstone National Park and 3,000 elk north of the park.

These numbers were 6 percent lower than the 2012 winter count of 4,174. Looking back further, between the winters of 2007 and the end of winter 2011, elk numbers ranged from 4,635 to 7,109.

The working group monitors trends of the northern Yellowstone elk population and evaluates the relative contribution of different components of mortality, including predation, environmental factors and hunting.

Formed in 1974, the group works to preserve and protect the long-term integrity of the northern Yellowstone winter range for wildlife species by increasing scientific knowledge of the species and their habitats, promoting prudent land management activities, and encouraging an interagency approach to answering questions and solving problems.

It is comprised of resource managers and biologists from Montana FWP, YNP, the Gallatin National Forest and the U.S. Geological Survey-Northern Rocky Mountain Science Center in Bozeman.