Jeff Koenings, Ph.D.
Director

Jerry Gutzwiler
Chairman
Washington Fish &
Wildlife Commission
 

Mule deer research includes ultrasonography, WSU nutrition study with captive herd
Posted August 2002

Summary
Now in its second year, WDFW's eastern Washington mule deer research includes body condition scoring using ultrasonography for comparison with a captive deer herd diet and nutrition study at Washington State University (WSU). In this part of the five-year multi-cooperator project, researchers hope to find how doe deer body condition, which is affected by different forage nutritional levels across the study area, in turn affects reproduction and ultimately overall herd health and survival. The results could help determine how to improve protection and enhancement of mule deer habitat and management of herds.

By W. L. Myers, Jr., Wildlife Biologist
WDFW Wildlife Program

WDFW's five-year research project to learn more about mule deer populations in northeast and north-central Washington is now in its second year with expanded activities underway. The project includes body condition scoring using ultrasonography for comparison with a captive deer herd diet and nutrition study at Washington State University (WSU). The study area, where to date 184 mule deer does have been captured and equipped with radio telemetry or satellite GIS (Geographical Information System) collars, covers all or parts of Chelan, Okanogan, Ferry, Stevens, Lincoln, Adams, Whitman, and Pend Oreille counties. In many of these areas, mule deer populations have been declining, as evidenced by survey results and hunter harvest.

One factor in those declines may be low nutrition forage. Doe deer with diet deficiencies could have later-than-optimal pregnancies, produce fawns with low birth weights, abort fetuses, have stillborns, or not even conceive. Poor nutrition is reflected in deer body condition and fat levels. Those conditions are being measured through ultrasonography (the same ultra-sound technology used in human health care) in the collared does when they are re-captured twice a year - once going onto winter range and again as deer leave the range at the end of winter. This body condition information from wild deer in the study area will be compared to body condition data collected from the captive herd at WSU to determine if diet deficiencies are part of the problem.

The WSU deer diet study involves 40 female mule deer fawns. Some of the fawns were collected in spring 2002 from state licensed wildlife rehabilitators who receive them as orphans or pick-ups. Many were captured from the wild in an area of Whitman County where mule deer have been causing agricultural crop damage and hunting permits have been increased to reduce their numbers. The fawns will be held in captivity for the rest of their lives, so they are purposely being habituated to their human handlers for ease of operation as the study proceeds.

Once the fawns are weaned from their bottle-fed milk formula, group feeding trials will begin. Some groups will receive high nutritional diets, others low. Their body condition will be measured periodically using the same ultrasonography as in the wild deer re-capture portion of the research. They will be bred by captive bucks and their reproductive success or failure tracked.

By comparing the body condition measures between the captive deer on controlled diets and the wild deer, WDFW researchers hope to gain information that may connect the physical condition and fawn production of individual deer with on-the-ground habitat conditions. Vegetative mapping and evaluation of nutritional values of forage species work began in the spring of 2002. The results may indicate needs to improve, enhance or protect mule deer habitat in some areas, or simply change harvest management to reduce mortality on herds that are less than stable.

Other possible factors in mule deer declines are also being explored in this multi-faceted research project. The collared deer are monitored weekly to track movements, determine habitat preferences, calculate population densities, measure herd boundaries and home range sizes, and learn rates, patterns, and causes of death. Surveys are also being conducted to measure deer numbers, age and sex composition. The information is needed to learn more about population regulatory mechanisms and landscape-level habitat relationships.

Some of the data collected is being used to evaluate the effectiveness of the traditional "density-dependent" model of mule deer harvest management. Harvest rates are dependent on the density of the deer population, which is dependent on available habitat. The density dependent management model assumes that hunting harvest does not add to overall deer mortality, but that as hunting harvest increases, natural mortality decreases. This model was developed from white-tailed deer population studies and may not be appropriate for managing mule deer. With a better understanding of mule deer population dynamics, WDFW should be able to more carefully manage Washington's mule deer through hunting restrictions and habitat protection.

More mule deer does will be equipped for monitoring as the study continues. That process starts with capturing the animals using a helicopter net-gunning crew that slings the netted deer to a site for processing by WDFW and volunteer crews. The deer are weighed and measured, and blood and fecal samples are collected for laboratory assessments of disease exposure, trace element levels, DNA and parasite loads. They are examined manually and through ultrasonography to determine body condition, pregnancy, and fetus size and number. The deer are equipped with radio telemetry or GIS collars. Prior to release, the deer receive shots of long-acting penicillin and a selenium-vitamin E compound to help mitigate the stresses of capture and handling.

Starting in the winter of 2002-03, a number of six-month-old mule deer fawns in each site will also be radio tagged to assess survival and dispersal.

Researchers from WSU's Large Carnivore Laboratory are also investigating the relationships between mule deer, white-tailed deer, and mountain lions as part of this project.

Deer monitoring is conducted by graduate students from the University of Washington, Washington State University, Central Washington University, and University of Idaho. Volunteers from the Inland Northwest Wildlife Council and Asotin County Sportsmen Association are also helping capture and monitor the deer.

This project is truly an inter-agency one and would not be possible without the support and involvement of many cooperating entities, including the Bonneville Power Administration, Colville Confederated Tribes, Spokane Tribe, Kalispel Tribe, Chelan County Public Utility District, U.S. Forest Service's Colville and Okanogan National Forests, the Bureau of Land Management, Washington Department of Transportation, Washington Department of Natural Resources, Northwest Okanogan Sports Council, Inland Empire Chapter of the Safari Club International, and the Mule Deer Foundation.

Related Links:
Five-year, cooperative mule deer study underway in eastern Washington

Author Biography

Woodrow L. Myers has a B.S. in wildlife resources from the University of Idaho and has been employed with the Washington Department of Fish and Wildlife (formerly the Department of Wildlife and Department of Game) since 1977. He has been a member of The Wildlife Society for 27 years and has served as a board member of the state chapter. He started as a waterfowl biologist, first in the Columbia Basin of central Washington, then in the northwest corner of the state, covering upper Puget Sound. In 1984 Myers moved to Winthrop and for five years studied mule deer migrations, population dynamics, and habitat use. From there he moved his research activities to the Blue Mountains conducting investigations of elk population dynamics, habitat use, and calf survival. His focus for the next five years will be studying mule deer population dynamics and identifying limiting factors in eastern Washington.