|
The colonies of 23 species of aquatic birds were surveyed at 329 sites distributed throughout the St. Lawrence system east of Cornwall. Colonies are mainly established on isolated archipelagos with relatively untouched habitat, or on cliffs on the mainland. The colonies with the greatest number of species were found on the Sainte-Marie Islands (11 species), Baie des Loups Migratory Bird Sanctuary (10 species), Corossol Island (10 species), Bonaventure Island (10 species) and Brion Island (10 species). Currently, the colonies with the greatest numbers of a single species are on Bonaventure Island (which contains 30,000 breeding pairs of Northern Gannets and 35,000 breeding pairs of Black-legged Kittiwakes), and on some islands in the freshwater section, which contain thousands of Ring-billed Gulls (Deslauriers Island with 50,000 breeding pairs and Île de la Couvée with 30,000 breeding pairs). In addition, the heronry on Grande Île in the Berthier region, with over 1000 breeding pairs of Great Blue Herons, is currently the largest breeding colony for this species in the world.
Chapdelaine (1995), in his detailed study on population trends in seabirds in the estuary and Gulf, concluded that most seabird populations in the St. Lawrence are on the increase. In the seabird sanctuaries and conservation parks, where over 95% of alcid populations are concentrated, the increase is probably due to improved enforcement, public awareness and education programs. In addition, an unusually high abundance of prey fish such as sand lance and capelin resulting from the decrease in populations of predatory fish such as the Atlantic cod has led to the strong recovery of seabird populations in the Gulf of St. Lawrence.
Pelagic birds
In summer, some species of pelagic birds with salt glands (which allow the excretion of excess salt accumulated in the body) leave their breeding colonies in the Southern Hemisphere to take advantage of the Gulf's great biological productivity, particularly in the Esquiman, Laurentian and Anticosti channels and off the Gaspé Peninsula and New Brunswick, where they feed with our local seabirds.
Six pelagic species that breed in the Southern Hemisphere and are occasionally recorded in the Gulf of St. Lawrence in summer as "wintering" individuals include the Yellow-nosed Albatross, Cory's Shearwater, Greater Shearwater, Sooty Shearwater, Wilson's Storm-Petrel and Great Skua.
Jean-Luc DesGranges and Benoît Jobin
|
|
