Grasses: These make up a large portion of their diet, especially during the spring and summer months when they are abundant.
Forbs: These are broad-leaved herbaceous plants, including wildflowers, clover, and other non-grassy plants.
Shrubs: Deer browse on various shrubs, including willows, sagebrush, and aspen.
Trees: They may also eat twigs, buds, and leaves from trees like cottonwood, maple, and oak.
Fruits and Berries: Seasonal fruits and berries, such as chokecherries, serviceberries, and acorns, are part of their diet.
Lichens and Fungi: During the winter, when other food sources are scarce, deer may also consume lichens and fungi.
Seasonal Variations: Their diet changes depending on the time of year and the availability of different plants. During the spring and summer, they focus on grasses and forbs, while in the winter, they rely more on shrubs and twigs.
Factors Influencing Diet: Factors like altitude, habitat, and climate can also influence the specific plants that a mule deer might eat.
It's important to note that mule deer have a specialized digestive system that allows them to digest tough plant material. They also have the ability to store fat during the summer months to survive the leaner winter season.