Mule Deer - Foraging

Foraging

Mule deer utilize a wide variety of plant foods, and their preferences vary widely geographically as well as seasonally, but they are primarily browsers on woody vegetation and eat relatively little grass. They readily adapt to agricultural products and landscape plantings. In summer, Mule Deer chiefly forage on not only herbaceous plants, but also various berries (including blackberry, blueberry, salal, and thimbleberry). They also use grasses more than in winter. Mule deer are known to forage in summer on California Buckeye leaves, even though there is some evidence of that plant's toxicity.

In winter, these deer forage on conifers (especially Douglas-fir, cedar, Taxus yews, juniper), and twigs of deciduous trees and shrubs (esp. aspen, willow, dogwood, serviceberry, and sage). In season, they eat acorns and apples. Over much of the species range, snow and ice cover many food sources and the food that is accessible grows slower. The deer's metabolism slows and individuals become less active to survive in an environment with less food. A large fraction of the deaths in a mule deer population occur in the winter, especially during the first year of life.

During the winter, mule deer often move down from mountains, where the snow is deeper and covers most of the food, into valleys where there is less snow. Sometimes, in response to perceived distress, concerned people create feeding programs. Such supplemental feeding efforts may be harmful if not properly implemented. Supplemental feeding helps mule deer make it through a severe winter if the feeding is started early, long before the mule deer show signs of malnutrition or starvation. To effectively feed mule deer requires a three to four month commitment because it has to be started before poor range conditions and severe weather cause malnourishment. It must be continued until range conditions can support the herd.

Mule deer rarely travel far from water or forage, and often bed down within easy walking distance of both. Young mule deer generally forage together in family groups; older bucks tend to travel alone or with other bucks. Most actively foraging around dawn and dusk, they usually bed down in protected areas mid-day, but will also forage at night in more open agricultural areas, during full moons, or when pressured by hunters. Repeated beds will often be scratched level, about the size of a washtub. Temporary beds will seem little more than flattened grassy grounds.