Interspecific aggressive behaviour by long-toed lapwings (Vanellus crassirostris)

In this paper interspecific aggression is related to ecological relationships between bird species. Three kinds of relationships are distinguished according to the presence or absence of aggression and the degree to which resources are exclusively utilized: interspecific territoriality (aggression, exclusive use), partial exclusion (aggression, no exclusive use), and tolerance (no aggression, no exclusive use). Aggression by long-toed lapwings (Vanellus crassirostris) is examined within this framework, using quantitative data gathered through observational sampling. Lapwings were interspecifically territorial with one species, partially excluded five species, and tolerated four species. The results indicate that the function of interspecific aggressive behaviour may be related to competition, predation, or both.