Territorial Behaviour of Common Goldeneye, Barrow's Goldeneye and Bufflehead in Areas of Sympatry

Abstract

Like Barrow's Goldeneye Bucephala islandica and Bufflehead B. albeola, Common Goldeneye B. clangula defend territories on their breeding grounds. Territorial behaviour of the three species is similar: paired drakes exclude all conspecifics but their mates from their territories; interactions with neighbouring territorial drakes last longer, are less violent and more ritualized than interactions with strangers. All three species are interspecifically territorial and interspecific confrontations are similar to intraspecific ones. Both goldeneyes dominate Bufflehead. Barrow's Goldeneye appear more aggressive than Common Goldeneye but neither species clearly dominate the other. Common Goldeneye and Bufflehead occur on both fresh and saline ponds whereas Barrow's Goldeneye prefer saline ones.