Interspecific Competition between White-Tailed, Fallow, Red, and Roe Deer

Abstract

We conducted a series of studies in the Dobris Forest, Czech Republic, to determine whether competition between white-tailed deer (Odocoileus virginianus) and sympatric cervid species could limit expansion of the white-tail population. We used grazing time among species as an indication of potential interspecific competition and predicted that grazing time on an open pasture would decrease if deer other than conspecifics were present or entered the pasture. We used 710 observational records in our analyses: 409 for white-tailed deer, 225 for fallow deer (Dama dama), 66 for red deer (Cervus elaphus), and 10 for roe deer (Capreolus capreolus). The time that white-tailed, fallow, and roe deer spent grazing was not affected by whether the pasture was harvested or whether any deer were present when the focal animal entered. We observed a strong tendency for grazing time by red deer to be directly related to the numbers of whitetails or female fallow deer visible before red deer entered the pasture, Grazing time of white-tailed and fallow deer increased if the focal deer was joined by another animal. For white-tailed and fallow deer, the anti-predatory strategy of joining a group may have been balanced by avoiding the most competitive classes of animals. Our results suggest that interspecific cooperative behavior, rather than interspecific competition, occurs among these sympatric cervids.