Nutrients Influence Diet Selection in Herbivores
Dykes, Jacob Lee.
AdvisorLashley, Marcus A.
CommitteeStrickland, Bronson K.
Reynolds, Daniel B.
Natural selection should favor selective foraging in deer to choose among nutrients in plant communities to meet their physiological requirements. I designed a two-tier cafeteria-style experiment where I measured plant nutritional quality and white-tailed deer (Odocoileus virginianus) use on 1) 15 species of herbaceous plants, and 2) 2 species of plants of manipulated nutrient concentrations. I tested the hypotheses: 1) deer use across plants would be influenced by plant nutrients, and 2) soil nutrients would influence plant selection by deer. My analyses indicated deer selected plants of low neutral detergent fiber and sulfur concentrations. However, deer selected for crude protein. I also confirmed soil nutrients indirectly influenced diet selection. Nutrient augmentation altered phosphorus concentrations within plants, and plant phosphorus concentration explained 47% of the variation in diet selection. My data indicated deer use both nutrient maximization and avoidance to balance diet selection and plants mediate the indirect effects of soil nutrients availability on herbivore diet selection.