David A. Budeau Una G. Swain Craig R. Ely 1987 <p>Interspecific aggression in waterfowl (Anatidae) is relatively common (McKinney 1965; Kear 1972; Savard 1982, 1984), but interactions leading to mortality of one of the combatants are rarely-observed in the wild. A recent debate (Livezey and Humphrey 1985a, 1985b; Nuechterlein and Storer 1985a, 1985b; Murray 1985) has centered on the proximate and ultimate causes of interspecific territoriality and killing in steamer-ducks (<i>Tachyeres</i> spp.), a group of large-bodies antids. We report here aggressive encounters between Greater White-fronted Geese (<i>Anser albifrons</i>) and Tundra Swans (<i>Cygnus columbianus</i>) during brood rearing on the Yukon-Kuskokwim Delta, Alaska, which on two occasions resulted in the death of a White-fronted Goose gosling.</p> application/pdf 10.2307/1368496 en Cooper Ornithological Society Aggressive encounters between tundra swans and greater white-fronted geese during brood rearing article