Migratory connectivity and spatio-temporal aspects of Pacific Barrow's goldeneye (Bucephala islandica) migration

Effective management of animals requires understanding movement throughout the annual cycle. We used satellite transmitters to track 229 adult Pacific Barrow's goldeneye (Bucephala islandica) captured across their full geographic range. We assessed the strength of migratory connectivity and determined latitudinal and sex effects on annual cycle phenology. Male and female goldeneye demonstrated strong migratory connectivity across wintering, breeding, and moulting stages. Males departed breeding grounds before females, spending less time on breeding grounds and more time on moulting grounds. Individuals at northern latitudes spent more time on wintering grounds than individuals at southern latitudes. These results indicate that, within a species, the timing of transitions throughout the annual cycle can vary with both sex and latitude. The spatio-temporal settings in which individuals occur, and the regional associations across annual cycle stages, inform the appropriate scale of management units and the effects of habitat perturbations at different places and times.