The elk, or $Cervus$ $canadensis$, is one of the largest land mammals in North America, inhabiting diverse ecosystems from mountain forests to open plains. As a large herbivore, this species relies entirely on plant matter to fuel its massive body, which can weigh over 700 pounds for a mature bull. Elk are ruminants, possessing a four-chambered stomach that allows them to efficiently digest tough plant fibers. Their diet is highly variable and directly linked to the availability and nutritional content of vegetation across the changing seasons, which is fundamental to their survival.
Primary Food Categories
Elk consume a wide spectrum of plants that can be categorized into three main structural groups: grasses, forbs, and browse. Grasses and sedges often form the bulk of the elk diet, particularly during the growing season when they are fresh and succulent. Common examples include bluegrass, wheatgrass, and various fescues, which provide a foundation of energy for the animals.
Forbs are broad-leafed, non-woody plants like clover, dandelion, and sticky geranium. They are frequently selected over grasses due to their superior nutritional content. During the late spring and summer, forbs can constitute anywhere from 60 to 100 percent of an elk’s diet because they are rich in protein and easily digestible. This preference helps meet the high demands of lactation and antler growth.
Browse consists of the leaves, twigs, and bark of woody shrubs and trees. While elk are primarily grazers, they readily consume browse material like willow stems, aspen bark, and young shoots. This category becomes increasingly important when herbaceous vegetation is scarce or inaccessible. Elk will even consume specialized items like wild mushrooms or acorns when available, which provide concentrated sources of fat and protein.
Seasonal Shifts in Diet
The nutritional composition of the elk’s diet changes drastically between the summer and winter months. During the summer and early fall, the abundance of high-protein grasses and forbs allows the elk to maximize their energy intake to build up fat reserves. This period of plenty is essential because female elk require a substantial amount of digestible energy to support pregnancy, lactation, and the raising of calves.
As temperatures drop and snow cover increases, the diet shifts from succulent green plants to less nutritious options. The animals must transition to dried, standing grasses and woody browse material, such as the bark of aspen and willow. While grasses may still make up a large percentage of the winter diet, the quality is severely reduced compared to the summer. This poor-quality winter forage limits the amount of energy an elk can obtain, requiring them to rely heavily on the fat reserves accumulated during the summer and fall.
This seasonal scarcity forces the elk to conserve energy by moving less, rather than trying to consume poor-quality forage in high volumes. The limited caloric intake from the winter diet helps the elk survive until the spring “green-up” returns. The early spring brings a flush of highly palatable and nutritious young shoots and grasses, which elk seek out to replenish depleted body condition and meet the increased energy demands of late gestation.
Foraging Methods and Ecological Role
Elk are considered intermediate feeders, meaning their feeding habits bridge the gap between pure grazers like cattle and pure browsers like moose. They employ both grazing, which involves clipping grasses and forbs close to the ground, and browsing, which entails nipping off woody stems and leaves. This flexibility in their foraging strategy allows elk to thrive in a variety of habitats and adapt to seasonal changes in vegetation availability.
The feeding patterns of elk exert a substantial influence on the structure and composition of plant communities in their range. Selective grazing and browsing can suppress the growth of preferred species, such as willow and aspen shoots, and promote the growth of less palatable plants. Elk contribute to nutrient cycling by returning organic matter to the soil through their waste products. Elk also play a role in seed dispersal, inadvertently carrying and depositing seeds across the landscape.