Interspecific aggression between fallow and roe deer

Information on interspecific aggression is scarce for wild ungulates. I described patterns and sex/age correlates of interspecific aggression between wild roe deer Capreolus capreolus and fallow deer Dama dama at feeding sites in Maremma Regional Park, central Italy. A previous study showed that fallow deer can actively exclude roe from feeding areas. Here I show that 81% out of 42 aggressive interactions were fallow–roe deer aggressions, whereas 19% were roe–fallow aggressions. No aggressive interaction involved physical contact between opponents and roe deer were displaced in all events. When roe deer avoided fallow deer, the probability of remaining feeding increased significantly with respect to when aggression occurred. Fallow deer males, especially yearlings, were more aggressive than females to all roe deer sexes/age classes. For fallow deer, aggression was an efficient way to monopolise the access to foraging space. For roe deer, spatial avoidance of fallow was a way to remain at feeding areas.