By Todd Glaser
In the late 1990s, Montana Fish, Wildlife and Parks developed a mule deer management plan that links population goals, harvest regulations, population monitoring and population modeling. One aspect of the plan was to increase the amount of monitoring scheduled on 13 of the 80 areas statewide designated as mule deer population census areas.
Bitter Creek, a high quality prairie mule deer habitat in Region 6, was one of the 13 new census areas. Bitter Creek is located approximately 25 miles northwest of Glasgow and 25 miles south of the Canadian border.
FWP selected Bitter Creek to be the first in a series of four-year pilot studies planned on these census areas. This study will identify the yearlong range of the deer, important habitat, population size, mortality rates and the accuracy of aerial surveys.
"We're collecting detailed answers to a few key questions, that will result in FWP making better overall management decisions about habitat projects and hunting seasons," said Pat Gunderson, FWP Glasgow wildlife biologist.
Two years into this pilot study, wildlife biologists are already discovering valuable information. In February 2000, 50 adult female mule deer were net gunned by helicopter across the 100-square mile area. Biologists obtained blood samples, determined ages and then placed radio transmitters on each deer. One-third of the deer were at least 10 years old.
Since being collared, the animals' locations are checked twice a month by air. Nearly 2,000 locations have already been recorded during the study, helping to document important seasonal habitats.
"We assumed mule deer wintering in Bitter Creek included year-long residents and deer that migrate short distances to summer range. What we discovered is that there are yearlong residents and long-distance summer migrants," said Gunderson.
Nearly half of the 50 deer migrated north into or near Canada to summer. A few summered as far as 60 miles from the winter home range. While spending the winters on only 100 square miles, the deer summer on a 2,000 square-mile area.
Since the study began, 20 deer have died. The natural mortality rate this past year was quite high, primarily among older deer. The recovered collars were placed on "new" deer in February. This time, the age structure of the deer was much younger than in the first radio-collaring operation. Over half of the animals were younger than four years old. Replacing the collars on new deer will assure an adequate sample size throughout the study.
Bitter Creek is just one of many areas that are essential to Montana's mule deer. Management studies like this one benefit mule deer and their habitat. Ultimately, the benefits trickle down to all who enjoy viewing and hunting the magnificent Montana mule deer.
Note: Detailed information on FWP's mule deer management called the Adaptive Harvest Management Plan for Mule Deer is available on the FWP web site at fwp.state.mt.us under Hunting.