Elk are large herbivores thriving across Arizona’s varied ecosystems, their diet influenced by diverse plant life. Reintroduced in the early 1900s, these animals adapt their foraging habits to specific vegetation found in different habitats. Understanding their consumption provides insight into their ecological role and how they sustain themselves.
Primary Forage in Arizona
Elk in Arizona are adaptable eaters, consuming a variety of plant materials: grasses, forbs, and woody browse. Grasses form a substantial portion of their diet, averaging around 73% of their intake when available. Common grass types include wheatgrass, bromegrasses, bluegrass, and fescue.
Elk also forage on forbs, which are broad-leafed, non-woody plants like wildflowers and weeds. Examples include dandelion, clover, sticky geranium, aster, and wild lupine. When herbaceous vegetation is less abundant, elk browse on shrubs and tree components such as twigs, leaves, and bark. Their woody plant diet can include species like cliffrose, serviceberry, aspen, oak, pine, juniper, sagebrush, rabbitbrush, and manzanita.
Seasonal Variations in Diet
Elk diet in Arizona shifts throughout the year due to changing food availability across seasons. In spring and summer, when herbaceous growth is plentiful, elk primarily feed on abundant grasses and protein-rich forbs like clover and dandelion. This high-quality forage supports functions such as gestation and lactation.
During fall, as green plants become scarcer, elk transition their diet to include more browse, such as shrubs and tree twigs. Certain plants, like Oregon cherry and prairie sageworts, produce a sugar boost after the first frosts, providing calorie-dense food that helps elk build fat reserves for colder months. In winter, when snow may cover herbaceous vegetation, their diet primarily consists of dry grass and browse. Aspen bark becomes an important food source during these lean times. Elk also undertake seasonal migrations, moving from higher elevation summer ranges to lower elevations in winter for milder temperatures and more accessible forage.
Water and Mineral Consumption
Water is important for elk survival, obtained from various sources throughout Arizona’s diverse terrain. These include natural streams, rivers, springs, and snowmelt. Elk can also acquire moisture from succulent plants they consume.
In addition to water, elk require various minerals for their health and development. They often acquire these nutrients by consuming mineralized soils or visiting natural mineral licks. These sources provide minerals such as sodium, magnesium, and phosphorus, important for recovery after winter, antler growth, and supporting nursing cows.
Influence of Habitat and Human Presence on Diet
The availability and quality of elk forage in Arizona are influenced by environmental factors and human activities. Habitat fragmentation, often caused by land development and road construction, can limit elk access to important feeding grounds and disrupt movement patterns. Increased human presence, including recreational activities and traffic, can also alter elk behavior, leading to heightened vigilance and reduced foraging time, impacting their nutritional intake.
Forest management practices, such as prescribed burns, can positively affect elk diet by improving habitat conditions. These controlled burns reduce forest density, allowing more light to reach the forest floor and promoting the growth of grasses, forbs, and shrubs that elk consume. Prescribed burns also return minerals like phosphorus and nitrogen to the soil, boosting plant growth and enhancing forage quality for elk.