McInnes and Varva looked at the species and amount of vegetation consumed by cattle, feral horses and pronghorn to try and discern the possibility of competitive exclusion or noncompetitive coexistence that may exist between these animals. They found that cattle and feral horse diets, composed mainly of grass, had a 90% overlap in the summer, but did not seem under any real competition during this study. The authors assessed that, under poor range conditions, it would be quite possible for these two species to exclude one another. Pronghorn diets were heavy in forage and browse so they did not have much overlap at all with horses and cattle. McInnes and Varva also found that pronghorn diets have much higher proportions of crude protein and consistently lower levels of ADF than that of cattle and horses.
Citations and enhanced abstracts for journals articles and documents focused on rangeland ecology and management. RSIS is a collaboration between Montana State University, University of Idaho, and University of Wyoming.