Elk (Cervus Canadensis) preference for feeds varying in selenium concentration

Area of Science:

• Animal Ecology
• Nutritional Ecology
• Wildlife Nutrition

Background:

• Selenium-accumulator plants are often unpalatable to large ungulates.
• Elk (Cervus canadensis) in Idaho inhabit areas with selenium-rich plants, but their dietary preferences are not well understood.
• Understanding elk dietary preferences is crucial for managing wildlife in selenium-affected ecosystems.

Purpose of the Study:

• To determine elk preference for feeds with varying selenium concentrations under controlled conditions.
• To investigate the influence of plant selenium concentration on elk dietary choices.
• To provide data on elk's ability to discriminate against high-selenium forages.

Main Methods:

• Seven yearling female elk were fed alfalfa pellets with added western aster to achieve selenium concentrations of 0.4, 5, 20, 50, and 100 mg/kg.
• Three feeding trials were conducted with varying combinations of selenium concentrations offered to the elk.
• Pellet consumption was measured to assess elk preference and discrimination against different selenium levels.

Main Results:

• Elk consumed significantly less of the higher selenium-containing pellets (5, 20, 50, 100 mg/kg) compared to the control (0.4 mg/kg).
• Elk demonstrated clear discrimination against pellets with the highest selenium concentrations, especially when multiple choices were available.
• Consumption patterns indicated a preference for lower selenium levels, with significant avoidance of concentrations above 5 mg/kg.

Conclusions:

• Elk are likely to avoid forages with high selenium concentrations in their natural habitat.
• Dietary selection by elk can mitigate potential selenium toxicity from accumulator plants.
• These findings have implications for wildlife management in areas with selenium-rich vegetation.