Mule Deer


I come from an area in Maine where the prolific Whitetail deer bed down around my house during the winter, birth their fawns in the spring in my wildlife sanctuary, roam around my field in female dominated groups with young during the summer. It isn’t until fall that I usually meet the bucks coming in to feed on the sweet wild apples outside my window. My point here is that although I never take their presence for granted, interacting with deer is simply part of my life.

When I first moved down by the river in Abiquiu, I used to see mule deer early in the predawn hours outside the Trailercita. Sometimes I would startle one or two when I walked in the Bosque and noted that both elk and mule deer bedded down in wild grasses making a circular depression much the way a dog will do before it sleeps.

After I moved into the Casita and began to walk down to the river every morning in the twilight hours I would often meet deer in the next field or on the island. I also tracked them through the Bosque surprising one or two occasionally. I didn’t realize until this fall how much seeing these animals made me feel at home.

When I returned to Abiquiu in September I immediately noticed that the deer were no longer bedding down in the Bosque. After being here for almost three months I have yet to glimpse the sight of even one mule deer. The loss of these ungulates disturbs me greatly. Where have they gone?

Just last week I noticed a deer scrape in the Bosque and tracked one mule deer, and one elk that had traversed the path and jumped the fence onto a more thickly vegetated area.

Because November marks the beginning of the rut the males are on the move and some are also beginning to shed their racks of antlers. I keep a sharp eye on the two junipers that are missing branches in the Bosque to see if more bark has been denuded, but as far as I can tell only one mule deer seems to be responsible for the scrape (elk don’t shed antlers until early spring). I just wish I could get a glimpse of one of these beautiful animals once more…

The single defining characteristic of mule deer is their large ears, which are about three-fourths the length of the head. They have a distinctive black forehead, or mask, that contrasts with a light gray face. In the summer, mule deer are tannish-brown and in the winter are brown and gray in color. They have a white rump patch and a small white tail with a black tip. When running, they bound – all four hooves push off the ground at the same time. Although this leaping slows them down, it allows them to leave predators behind by quickly ascending steep slopes or jumping unpredictably over large obstacles. Their large, keen eyes and ears allow them to locate distant predators like coyotes and wolves.

Mule deer range from 3 to 3.5 feet tall at the shoulder, 4.5 to 7 feet long, and have a tail that is five to eight inches long. They can weigh between 130 and 280 pounds. Like other species of deer, the females are smaller than the males.

These animals are among the most beloved and iconic wildlife of the American West. Mule deer are found especially in the Rocky Mountain region of North America. They are adapted to arid, rocky environments and thrive in habitats that have a combination of early-stage plant growth, mixed-species plant communities, and diverse and extensive shrub growth. A mixture of plant communities provides better forage than any single species. Plants that are young and emerging are more nutritious than mature trees and shrubs. I can’t help wondering if this need for young and intermediate plant growth is one reason why these grazing animals are disappearing from the Bosque now that so much of it has been opened up and cut.

Mule deer are very selective feeders, nibbling on herbaceous plants and the leaves and twigs of woody shrubs. Instead of eating large quantities of low-quality feed like grass, they must select the most nutritious plants and parts of plants. Because of this, mule deer have more specific forage requirements than elk that share their habitat.

Between November and January (depending on the locality), bucks lock antlers competing for the right to mate with females. The victorious male attract females to them and attempt to defend them against the attention of other (often younger) bucks. Sexual maturity is attained at the age of about 18 months in does, but young males are barred from participation in the rut until they are three to four years old.

The gestation period is approximately 200 to 210 days and occurs during the summer. The female sequesters herself and gives birth in a protected spot, where the spotted fawn remains for a period of a week or 10 days before it is strong enough to follow the mother. It is during this period that the young are most vulnerable to predation. The young ones are weaned at about the age of 60 or 75 days, at which time they begin to lose their spots. Mule deer usually live 9 to 11 years in the wild.

In some areas the mule deer will have separate summer and winter ranges, with a migratory path connecting them. In the mild climates they will not migrate. They live in small groups of three to five individuals.

During he winter larger groups often come together to feed. It appears that the females have a small home range, living out their lives close to the areas where they were born, while the males migrate longer distances. I have noted the same tendency with respect to Whitetails.

For decades, western Colorado has been home to some of the country’s largest mule deer herds. Herds in a portion of northwestern Colorado were once so prolific that the area was dubbed “the mule deer factory.”

Unfortunately, I also discovered that overall Mule deer populations have been dropping across the west for several years, which also may account for my seeing less of them. State wildlife managers and wildlife groups are trying to determine what’s behind the decline. It amazes me that climate change is not mentioned as a factor. Naturally, shrinking habitat due to development including that of increased oil and gas drilling is also a factor contributing to the decrease of this species. The renowned White River herd in northwest Colorado has plummeted from more than 100,000 in the early 1980s to the current estimate of 32,000 deer according to the National Wildlife Federation. From this naturalists point of view a loss of two thirds of any deer population anywhere is cause for deep concern.