Nesting biology of pacific loons, Gavia pacifica, on the Yukon-Kuskokwim Delta, Alaska

The nesting biology of Pacific Loons, Gavia pacifica, was studied from 1973 to 1975 on the Yukon-Kuskokwim Delta, Alaska. Loons maintained territories on ponds throughout the pre-nesting period. Both adults incubated eggs and raised the young. Males incubated more than females during early incubation, and females more than males during late incubation. The female assumes much of the early brood rearing, with the male assisting more when food demands of young increase later in brood rearing.