The Washington Department of Fish and Wildlife (WDFW) has initiated a five- year research study to learn more about declining mule deer populations in northeast and north-central Washington.
The study, which includes parts of Chelan, Okanogan, Ferry, Stevens, Lincoln, and Pend Oreille counties, is in cooperation with the Colville Confederated Tribes, Chelan Public Utility District (PUD), Inland Northwest Wildlife Council, and the U.S. Forest Service's (USFS) Colville and Okanogan National Forests.
To date, 34 mule deer does have been captured and marked with radio- telemetry collars to allow monitoring of their movements. The monitoring will help determine habitat use, herd boundaries and home range sizes, population densities, and mortality rates, patterns, and causes. Blood samples and measurements taken when the deer were captured will also help determine health and productivity. Several hundred mule deer will be marked with radio equipment or colored collars throughout the study period.
WDFW wildlife research biologist Woody Myers is coordinating the study, with field work assistance from the Colville Tribe and USFS biologists and University of Washington and University of Idaho graduate students.
"The general trend suggests a declining mule deer population in Washington," Myers said. "Harvest management has been based on what is called a ‘density- dependent' model, where harvest rates are dependent on the density of the deer population, which is dependent on available habitat. It's assumed that hunting harvest doesn't add to overall deer mortality, but is just a part of it. It's also assumed that as hunting harvest increases, natural mortality decreases, since only so many deer can live in only so much habitat."
Myers said that this management model, which was developed from white-tailed deer population studies, may not fit mule deer. Information on the dynamics of Washington's mule deer population is very limited, he noted, and no information is available on population regulatory mechanisms and landscape level habitat relationships. No information has been collected in Washington that connects the physical condition and fawn production of individual deer with on-the-ground habitat conditions. Those are the gaps the new study intends to fill, he explained.
"The results of this study should allow us to more carefully manage Washington's mule deer through improved hunting regulations and habitat management," Myers said.