Mule deer research goes high tech

  Space is one of the essential components of wildlife habitat. On-going research in Wyoming shows that outer space may be increasingly important to the well being of wildlife populations, according to the Wildlife Management Institute. To understand better impacts of energy development on public lands, Wyoming's Cooperative Fish and Wildlife Research Unit has been conducting a study of mule deer movements and habitat choices. Satellites are used to locate the deer. This study, conducted in cooperation with Ultra Petroleum Company, was initiated in 1998 and recently has concluded.

  The Sublette mule deer herd in western Wyoming numbers approximately 30,000 and is notable for producing trophy-class animals. This herd moves significant distances in its annual cycle, thus necessitating the satellite technology that can find and track the animals over the vast area of the herd's range.

  Sublette mule deer traditionally have congregated during winters on relatively undisturbed sagebrush deserts of the Green River Basin. However, subdivision expansion and development of natural gas reserves in the 1990s threatened much of the herd's crucial winter range and migration corridors. As a result, there was urgent need to identify movement patterns and seasonal habitat preferences of these mule deer to determine how to minimize the subdivision and energy development impacts.

  The study has involved fitting 10 deer with Global Positioning System (GPS) collars. The collars--programmed to record locations three times a day during spring and autumn migrations and store as many as 700 total locations of each deer-- have functioned properly and been about 75 percent effective, generally storing more than 500 locations per deer.

  GPS collars are unbiased relative to weather conditions, time of day and other common problems associated with standard aerial telemetry monitoring systems. For comparisons with previous technology, the Wyoming study used another 140 mule deer marked with traditional VHF radio collars.

  At the end of each measurement year, the GPS-collared deer have been recaptured and the GPS data downloaded into computers for analysis. The traditional VHS radio telemetry operation involves a larger number of deer and more extensive capture and recapture effort, and tracking and recording must be done by persistent field personnel using aircraft--all of which is expensive. Furthermore, the 140 VHF collars identified a total of about 1,500 locations, at a cost of approximately $69.00 each. The 10 GPS collars provided 20,000 locations at $0.90 each. To an extent not possible with the VHF telemetry systems, the GPS data have allowed Wyoming Coop Unit researchers to identify the Sublette mule deer herd's specific migration routes, highway crossings and seasonal ranges. The information is providing a much clearer picture of the animals' movement patterns and habitat choices. This information can be used by land and wildlife managers in the design and location of future developments. An obvious drawback to GPS collars is the high cost per unit, which limits the number of deer available for study.

  At the outset of the study, the GPS collars cost about $4,000 each. Most recently, the per unit cost has dropped to about $1,500, and the collars themselves are lighter, with greater programming flexibility, larger storage capacity and automatic removal option.

  The Sublette mule deer study is extremely important for protecting the viability of one of North America's most valuable big game populations. A report summarizing this work is available from the Wyoming Cooperative Fish and Wildlife Unit.

  For more information on the herd, the study and the GPS technology being used, contact Fred Lindzey, Wyoming Cooperative Fish and Wildlife Unit, at 307-766-5415. (lhc)