Mule Deer Fanatic

Many will argue that the real problem with declining mule deer populations is deteriorating winter habitat, and that National Parks are evidence that habitat, not predation, is the limiting factor in mule deer populations. If you broaden your view a little you will see that, in many areas, there is virtually unlimited winter range but limited summer range. Summer range, not winter range, controls the carrying capacity of the mule deer in those areas. It is almost always the case that the summer range in any area can support significantly more mule deer than are currently present. And still the deer are no longer able to increase to the level of the summer range capacity.

In those areas where the limiting factor is winter range, there are 3 different conditions that are typically cited as important: 1) quality of browse; 2) quantity of browse; or 3) scarcity of cover. It is difficult, at best, to assess the quality of the browse. It has been assumed that older plants such as sage brush, have lower quality than young plants. I have participated in reseeding projects, some of which have now had years to develop. I have observed areas where juniper have been removed. I have also observed numerous controlled burns. None of these, however wonderful they may be, have brought back the mule deer in the affected areas.

There are numerous areas where the quality of the browse has improved even in non-conventional ways – such as in subdivisions which are planted with lush, green, well-cared for browse. In some areas the quality of browse has degraded because of decreased use by domestic livestock. If livestock do not overgraze an area, they can actually improve the quality of the browse for mule deer.

Concerning the quantity of browse, there are probably as many areas where the quantity of browse has increased as there are areas where it has decreased. One reason for this is that far fewer deer are consuming the plants than was the case in the past. With few exceptions, there is in every area adequate quantity of browse for more mule deer than are present. In years when there is deep snow, the snow can effectively reduce the quantity of feed available to the mule deer.

Because of snowmobiles, atv’s, high numbers of domestic dogs, and such – mule deer are harassed in winter time more than they used to be. If their cover is not adequate, the stress from harassment is compounded by the lack of cover. There may end up being a greater distance separating cover from browse- increasing the likelihood of exposure. Mule deer are nervous creatures anyway and harassment during winter degrades their health with or without cover. Unbroken expanses of Juniper do not help deer much, but a mosaic of trees and browse is highly desirable.

For those who believe that predators don’t have any negative impact on mule deer, and that pristine vegation is better than manipulated vegetation, the National Parks should then have such an abundance of mule deer as to make the deer a nuisance. Such is not the case, there are fewer mule deer in National Parks than in the areas surrounding the Parks. The deer in the Parks are typically more visible, but are not more plentiful. Yellowstone is a classic example of the impact of predation in the presence of pristine habitat. The habitat has not saved the game from predators. Since the introduction of wolves in Yellowstone, the game animals have diminished drastically with no apparent change in habitat.