The effect of interspecific aggression on territorial dynamics in acrocephalus warblers in a marsh area of north-western italy

Abstract

Observations carried out on an Acrocephalus community in north-western Italy during the breeding period have confirmed the occurrence of interspecific territoriality, with Acrocephalus arundinaceus aggressively dominant to-ward A. scirpaceus and A. palustris. The adaptive character of such an inter-specific territoriality is discussed. Data seem to suggest that shifts in territories are also depending on interspecific interactions, even though intraspecific inter-actions have been confirmed to have the major weight in such a phenomenon. Great Reed Warbler territories resulted to be significantly larger than those of Marsh and Reed Warbler. It may be supposed that the Great Reed Warbler has larger territories as a consequence of its stronger aggressiveness. © 1991 Taylor & Francis Group, LLC.