BEHAVIORAL PLASTICITY IN A SHORT DISTANCE MULE DEER MIGRATION. TO GO OR NOT TO GO?
Jerrod L. Merrell; University of Nevada, Reno; 121 Southend Dr, Dayton, NV, 89403; (775) 225-1857; jmerrell@cabnr.unr.edu; Kelley M. Stewart, Shelly D. Blair
Migration maximizes accessibility of high-quality forage in variable systems. This ubiquitous behavior is found in taxa worldwide. Large herbivores in Africa use long distance migrations to obtain seasonally productive forage. Mule deer (Odocoileus hemionus) and elk (Cervus canadensis) of the western US migrate to lower elevations when snow leaves high elevation forage inaccessible. A migratory herd of Rocky Mountain mule deer (Odocoileus hemionus hemionus) and Columbian Black-tailed deer (Odocoileus hemiones columbianus) found on the western slope of the Sierra Nevada Mountains in California show plasticity in migration behavior. The average migration distance for this herd is 32 km. In these migrations we see back and forth movement between habitat patches. These exploratory movements range from less than 1 km to more than 38 km. We hypothesize these individuals are testing forage quality in holdover locations and then deciding to continue with migration or move back to seasonal range. We have observed 95 migrations from 32 collared female deer. Individual variation in migration ranges from 25-141 days. Plasticity in migration behavior allows for optimal use of higher quality forage and may be an adaption to changing climate conditions.
Ecology and Conservation of Mammals II