Île Grosse Boule and Île La Petite Boule are coastal islands that are part of the Sept-Îles Archipelago, Québec. These two islands are located 5.2 and 3.4 km off the mainland, respectively, in front of the city of Sept-Îles. Sept-Îles is on the shore of the northwest part of the Gulf of St. Lawrence. The islands themselves are round-shaped, hilly and crossed by numerous small intermittent streams. The surface of these islands, which are only 300 m apart at their closest, is covered with mixed woods, mostly White Birch and White Spruce.
Île Grosse Boule and Île La Petite Boule have seven breeding seabird species: Black Guillemot, Razorbill, Great Black-backed Gull, Herring Gull, Common Eider, Black-legged Kittiwake and Double-crested Cormorant. At the last complete survey, in 1985, the total number of colonial birds on both islands was close to 14,000. There are three large colonies, with two species present in significant numbers. A 1,444 pair Double-crested Cormorant colony is located on La Petite Boule. This represents 1.5% of the Atlantic population. Herring Gulls breed on La Petite Boule, (3,570 pairs) and on Grosse Boule (1,671 pairs). Their combined total of 5,241 pairs, accounts for 4.3% of the North American population.
Some other species that were recorded as breeders during the most recent complete survey include: Black Guillemot (35 birds), Razorbill (9 birds), Black-legged Kittiwake (192 pairs), Great Black-backed Gull (379 pairs, almost 1% of the global population) and Common Eider (76 pairs).
BirdLife International (2020) Important Bird Areas factsheet: La Grosse Boule Island. Downloaded from http://www.birdlife.org on 29/11/2020.