Spring migration of scoter and loon species in the Bay of Fundy: quantifying environmental influences, estimating afternoon migration, and analyzing trends between 2000 and 2017

Abstract

Waterfowl migration has been monitored at the Point Lepreau Bird Observatory in the Bay of Fundy every spring since 1996. Derived scoter and loon population estimates from previous studies have suggested declines but there is uncertainty in the estimates due to unequal sampling during mornings and afternoons. This study examines: 1) if afternoon migration rates can be accurately modelled using morning rates and environmental conditions; 2) scoter and loon migration rates through the Bay of Fundy; 3) changes in migration rates between 2000 – 2017. I found: 1) morning migration and environmental data were insufficient to accurately model afternoon migration; 2) greater numbers of Black and Surf Scoter migrate through the Bay of Fundy; 3) migration rates of scoter species have declined, and loons increased between 2000 and 2017. Afternoon migration monitoring is important in maintaining effectiveness of this and similar migration monitoring projects to evaluate changes in populations over time.