Odocoileus: White-tail and Mule Deer
Running Fawn 520

There are two species of deer in the refuge, the white-tailed deer (Odocoileus virginianus) and the mule deer (Odocoileus hemionus). They browse both in meadows and along the forest edges and use the deeper forest for shelter. 

White-tailed deer are the smallest members of the North American deer family, with the mule deer usually being the larger. White-tail deer are common in the Rocky Mountains and east from there. The mule deer are mainly found only in the Rocky Mountains and not east of the Missouri River. In the heat of summer deer usually inhabit the refuge's open fields and wetlands using the willows and the forest trees for shade. During the winter they generally keep to the forests, preferring the Douglas Fir and pine stands that provide shelter from the harsh winter weather.

One distinguishing difference between the mule and white-tail deer are the ears. The mule deer ears look over-sized for their heads, where the white tailed deer are proportioned properly to the size of their head. Also, the mule deer's tail is black-tipped but the white-tail deer's tail has an underside of white fur without the black tip.

Male deer, or bucks, have a large set of antlers which are discarded from late December through early March. The annual cycle of antler growth is regulated by changes in the length of the day. Only the bucks have antlers,  which start to re-grow almost immediately after shedding their previous antlers. The specific difference between the mule and white-tail deer antlers is that the mule deer's antlers fork as they grow instead of branching from a single main beam in the case of the white-tail deer.These antlers are used during the mating season as they fight over territory and females in sparring matches.

Female deer are also called does. They give birth to one to three young fawns at a time, usually in May or June after a gestation period of seven months. The young fawns are covered with a reddish-brown coat and white spots that helps them blend in with the forest. During their first 4 weeks, fawns hide on the forest floor with their head outstretched to avoid detection from predators while their mothers forage for food. After 4 weeks they are following their mothers, and by 2 months they are able to feed themselves.

Deer are herbivores that browse on most available plant foods including leaves, twigs, fruits, and berries of browse plants such as chokecherry, serviceberry, and snowberry. They will browse on some forbs during summer. Grasses are grazed in spring, and forbs are browsed in late spring and sometimes in the fall. The two species usually do not compete for the same food when their range overlaps as is the case in the refuge. The deer are not always easy to see because they usually only venture out in the dawn and dusk hours.

In the wild, deer, particularly the young, are preyed upon by bobcats, wolverines, mountain lions, coyotes and bears. They use speed and agility to outrun predators, sprinting up to 30 miles per hour and leaping as high as 10 feet and as far as 30 feet in a single leap.

Because the eyes of deer are located on the sides of their heads, they can see a 310 degree view around themselves. They have better nighttime vision than humans, but less accurate daytime and color vision. However, they rely on their keen sense of smell to sense dangers from predators.

Deer live short lives due to the harsh conditions in the wild. The average lifespan is about 2 to 3 years, with 10 years being an unusually high lifespan. However, captive deer are know to live an average of 16 years or more.

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Facts About Deer

Diet: Herbivore (browse leaves, twigs, fruits, and berries) 

Size:male weighs 250 to 275 lbs; female weigh 160 to 180 lbs. 

Lifespan: 2-10 years 

Social Structure: solitary