Seasonal occurrence of waterbirds in Minas Passage, Bay of Fundy, Nova Scotia, Canada, 2010 to 2012

Abstract

We determined patterns of seasonal abundance and diversity of seabirds and coastal waterfowl in Minas Passage, Bay of Fundy, Nova Scotia, Canada using quantitative, shore-based point surveys from mid-March to late August and mid-October to December 2010 to 2012. This area experiences the world’s highest tides and greatest tidal currents. We showed that species and seasonal cycles of waterbirds in Minas Passage reflect patterns typical of the inner Bay of Fundy and the northeast Atlantic coast of North America. The study highlights the importance of Minas Passage as an important local migration pathway for waterbirds including Black Scoter (Melanitta americana) and Red-throated Loon (Gavia stellata) passing through the Bay of Fundy. Large numbers of sea ducks (Black Scoter, Surf Scoter [Melanitta perspicillata], White-winged Scoter (Melanitta fusca), and Long-tailed Duck [Clangula hyemalis]), and Red-throated Loon were observed at the site in spring and fall, corresponding to known peak movements elsewhere in the Bay of Fundy. Fewest species and smallest abundances of waterbirds overall occurred in summer and early winter, while most species and largest abundances occurred in April-May and early November. Of the 46 species observed, resident breeders such as Herring Gull (Larus argentatus), Great Black-backed Gull (Larus marinus), Common Eider (Somateria mollissima), Black Guillemot (Cepphus grylle), and Double-crested Cormorant (Phalacrocorax auritus), were most abundant in spring to early summer during breeding and migrants including Red-throated Loon, Black Scoter, Ring-billed Gull (Larus delawarensis), Surf Scoter, and Northern Gannet (Morus bassanus) occurred in moderate numbers during migration periods.