PubMed · 2026-06-16
A study of five large grazing animals in Yellowstone found that how much individuals within a species vary their movements determines how much that species overlaps in resource use with other species. Animals with more predictable, uniform movement patterns (like bighorn sheep) competed less with neighbors than animals with highly variable individual movements (like elk and bison).
Species whose individuals moved more uniformly (bighorn sheep, pronghorn) overlapped less in resource use with other species than those with highly variable individual movements (elk, mule deer, bison).
Individuals tracked plant phenology (seasonal green-up) and snow conditions to access different quality forage across space, driving community-level resource partitioning.
Despite differences in movement strategies, all five Yellowstone ungulate species showed high overall similarity in resource use, suggesting interspecies competition was not a major driver of their ecology.