Interspecific territoriality and competitive interactions between American Black Ducks Anas rubripes and Mallard A. platyrhynchos

Abstract

Interactions between pairs of American Black Ducks and Mallards were studied at six sites in northeastern Nova Scotia during territory establishment. Interspecific territoriality was well developed and most frequently resulted in competitive superiority by resident pairs, regardless of species. Also, intruding pairs sometimes remained on territories already occupied by the other species. Exclusion of Black Duck pairs by Mallards occurred twice.