Once a year, the Washington Department of Fish and Wildlife (WDFW) conducts aerial counts of eastern Washington elk herds from helicopters or planes, usually in late winter/early spring. This is done to determine population trends, effects of management activities, and to monitor health of the entire herd.

Aerial counts are a common practice for wildlife and conservation agencies across the country. They allow biologists to cover large areas quickly and access rugged terrain to view animals not visible from the ground. The surveys are conducted before trees start to fill in for the warmer season to more easily spot animals. They are also more visible against the white backdrop of snow that remains in higher elevations in March. In addition, conducting the counts this time of year allows biologists to assess overwinter calf survival, which can vary depending on how harsh the winter was.

As with other ungulates, WDFW recognizes that elk have low energy reserves in late winter and keeps gates to some of the department’s wildlife areas closed through March to reduce human disturbances to the animals. Disturbing them for a few minutes once a year is far less stressful than repeated interactions with people hiking or doing other recreation activities in elk range areas.

“Because these are short, high intensity reactions (to the plane or helicopter), energy used by the animals is coming primarily from metabolism of blood glucose and muscle glycogen,” said Scott McCorquodale, WDFW’s authority on aerial wildlife counts and a specialist on elk. “They are not burning fat stored during these events. When animals are forced by interactions with humans to move over and over again though, or are reacting for extended amounts of time- as when disturbed by people on foot or in vehicles- energy used is coming from aerobic respiration, which uses fat stores as fuel.”

In light of wildlife having low energy reserves in late winter, some members of the public are concerned about the possibility of aerial counts harming animals.

“Elk are a species that evolved to flee perceived danger when necessary, even late in pregnancy,” said WDFW veterinarian Kristin Mansfield. “I wouldn’t expect a disturbance as brief as those used in aerial counts to have any harmful effects.”

All aspects of the Eastern Washington Aerial Elk Survey Protocol are observed during surveys. The protocol is 18 pages of information on why and how aerial counts are conducted. It includes implementation details for surveys, how and when flights are conducted, and even where the aircraft will be positioned over the herd when elk are sighted.

The protocol is supported by the Review of Big-Game Survey Methods Used by Wildlife Agencies of the Western United States[1], Idaho fish and Game’s Aerial Survey: User’s Manual, and other industry white papers and publications.

McCorquodale himself authored a peer-reviewed research paper on elk surveys called Sex-Specific Bias in Helicopter Surveys of Elk: Sightability and Dispersion Effects that was published in the Journal of Widllife Management.

More information on elk and their habitat can be found on the WDFW website at www.wdfw.wa.gov.

[1] Michael J. Rabe, Steven S. Rosenstock, and James C. deVos, Jr. “Review of Big-Game Survey Methods Used by Wildlife Agencies of the Western United States. Wildlife Society Bulletin, Vol. 30, №1 (Spring 2002) pp. 46–52.

The Washington Department of Fish and Wildlife is dedicated to preserving, protecting and perpetuating the state’s fish and wildlife resources.