Offshore Flight of Buffleheads, Bucephala albeola, After Twilight in Winter: An Anti-Predation Tactic?

Abstract

In winter, on Vancouver Island, Buffleheads depart from coastal marine feeding habitat shortly after the onset of civil twilight. This precisely-timed phenomenon may have evolved in response to predation pressure from Peregrine Falcons, Falco peregrinus. The dual habitat requirements of Buffleheads in Shoal Harbour Migratory Bird Sanctuary (1931) and Sidney Channel Important Bird Area are to be included within the proposed Gulf Islands National Marine Conservation Area.