Daytime spring migrations of Scoters (Melanitta spp.) in the Bay of Fundy

Each spring, Black Scoters (Melanitta nigra), Surf Scoters (M. perspicillata) and White-winged Scoters (M. fusca), pass through the Bay of Fundy in daytime on their northward migration to the sub-arctic breeding grounds. Their migrations along the Fundy coast were monitored from the Point Lepreau Bird Observatory at Point Lepreau, New Brunswick, from 1996 to 2004. Black Scoters migrated first (peak migration day: 13-17 April), followed by Surfs (23-25 April) and White-wings (22-28 April) which migrated together, although White-wings persisted over a longer period. Based on their rates of passage, we estimated the relative proportions of the wintering eastern North American populations of scoters, assumed to be of breeding age, which migrated by Point Lepreau each spring. We determined that 6-18% and 28-37% of the North American breeding populations of Surf Scoters and Black Scoters, respectively, utilized this northward migration route annually. The low numbers of White-wings (0.4-0.6%) suggested that larger numbers of this species employed a different migration route in spring or migrated at night. This observatory offers an exceptional facility for monitoring this group of sea ducks, over time.