Ask the Conservation Officer (CO)
idfg-staff
by Gary Hompland, Regional Conservation Officer
Question: "My whole life I've heard Fish and Game talk about buck:doe ratios. I'm not disagreeing with the importance of this statistic, but you can have a 10-1 ratio with a 1000 bucks to 10000 does just as well as 10 bucks to 100 does. Unit 54 has had a great increase in deer population since the doe hunts were eliminated. I drew this unit in '07 and would say it's the best I've seen it since the devastating winter of '92- '93. I'm concerned reinstating doe deer hunting will reduce the quality of this population."
Answer: Controlled hunt permit levels for deer are based on population estimates and trends. Your example was correct; the herd composition ratio is the same whether you have 10,000 deer or 1000 deer. However; the real question is: "In an area capable of supporting only 1000 deer would you prefer to have 900 does and 100 bucks or 750 does and 250 bucks?" The concept of carrying capacity (the maximum number of animals an area can support) is paramount in managing mule deer populations but is complicated by the fact that it is always changing due to natural and man-made events like drought, fire, and urban sprawl. Degraded or loss of habitat reduces carrying capacity.
It's very difficult to increase carrying capacity. In recent years the Department has coordinated habitat improvement projects utilizing volunteers on private, BLM, and U.S. Forest Service land. Planting bitterbrush on winter ranges, installing guzzlers for wildlife water, and aspen regeneration projects are all designed to improve the habitat's ability to support wildlife, or carrying capacity.
Mule deer populations achieve optimal reproduction (produce the maximum number of fawns) when they are managed below the carrying capacity. Use of hunting as management tool we can manipulate the population to maintain healthy, vigorous populations of both does and bucks.
Antlerless harvest is a valuable management tool and one that we continue to recommend when we believe it will help achieve our population management objectives. Some objectives include: managing deer numbers below carrying capacity in order to improve survival of adult does and optimize reproductive potential. Hunting antlerless deer is also used to reduce the magnitude of die-offs like occurred in 1992-93 as well as stimulate sluggish herds to rebuild more quickly.
Following the 1993 mule deer decline, antlerless harvest successfully stimulated reproduction and population growth in the Magic Valley. In the Bennett Hills, antlerless deer hunting stabilized deer numbers and allowed recovery of winter habitat after years of high deer numbers and overuse. The result was an improvement in winter range conditions and a deer herd that increased substantially within 3-4 years.
Some Idaho mule deer populations that have not had antlerless harvest since 1993 (15 years) remain depressed with low fawn production. Antlerless harvest may be considered to help stimulate those herds toward recovery and increased production.
Every 3-5 years mule deer populations are counted using a specially designed helicopter survey. During the interim years, we conduct surveys to track the proportion of fawns, does, and bucks in the population. Additionally, every year a sample of fawns and adult does is radio-collared to monitor survival in each Population Management Unit. We use these data and harvest estimates from the mandatory harvest report to monitor population status and trends.
If you have any further questions you may call the Magic Valley Regional Office of the Idaho Department of Fish and Game at (208)324-4350 or e-mail us at the Fish and Game web site at http://fishandgame.idaho.gov.