Deer are browsers. During the winter and early spring, they feed on Douglas-fir, western red cedar, red huckleberry, salal, deer fern, and lichens growing on trees. Late spring to fall, they consume grasses, blackberries, apples, fireweed, pearly everlasting, forbs, salmonberry, salal, and maple.
The mating or ‘rutting’ season occurs during November and early December. Bucks can be observed running back and forth across the roads in the pursuit of does. After the rut, the bucks tend to hide and rest, often nursing wounds. They suffer broken antlers, and have lost weight. They drop their antlers between January and March. Antlers on the forest floor provide a source of calcium and other nutrients to other forest inhabitants. Bucks regrow their antlers beginning in April through to August.
Two forms of black-tailed deer or blacktail deer that occupy coastal woodlands in the Pacific Northwest are subspecies of the mule deer (Odocoileus hemionus). They have sometimes been treated as a species, but virtually all recent authorities maintain they are subspecies. The Columbian black-tailed deer (Odocoileus hemionus columbianus) is found in western North America, from Northern California into the Pacific Northwest and coastal British Columbia
Food and Feeding Habits
Deer eat a wide variety of plants, but their main food item is browse—the growing tips of trees and shrubs. In late winter and early spring, deer eat grass, clover, and other herbaceous plants
Deer also eat fruit, nuts, acorns, fungi, lichens, and farm and garden crops if available. For their first few weeks of life, fawns thrive on milk, which is more than twice as rich in total solids as the best cow milk. Deer eat rapidly and, being ruminants, initially chew their food only enough to swallow it. This food is stored in a stomach called the “rumen.” From there it is regurgitated, then re-chewed before being swallowed again, entering a second stomach where digestion begins. From there it is passed into a third and then a fourth stomach, finally entering the intestine.
Shelter and Range Needs
Deer are sometimes referred to as “edge” species, meaning they thrive at the interface of openings and cover patches. This allows deer to feed in productive openings while being close to escape cover. Many wooded suburban environments, such as parks, greenbelts, golf courses, and roadsides, meet the needs of deer.
Mule deer can move long distances during spring and fall migrations to avoid mountain snow. Mule deer summering in the Cascades migrate as far as 80 miles to reach adequate winter range. Black-tailed and white-tailed deer normally reside within a ½ to 3 square-mile area; in mountainous locations, they move to lower elevations for the winter.