Cape Hay is located at the entrance of Lancaster Sound near the northwestern tip of Bylot Island. Bylot Island, which is situated immediately northeast of Baffin Island, is comprised mostly of Precambrian metamorphic rock. As part of the Arctic Cordillera, the island is quite mountainous with numerous glaciers and elevations up to 1,900 m above sea level. The site that contains the colonial seabirds is comprised of vertical cliffs of Precambrian dolomite that rise 60 to 460 m above sea level.
Offshore, the Lancaster Sound is a major migration route for marine mammals such as beluga, narwhals, ringed seals and harp seals. Polar bears are also numerous, and the north shore of Bylot Island is reported to be a maternity denning area and summer retreat.
During the 1970s surveys indicated that approximately 140,000 pairs of Thick-billed Murres were present at Cape Hay during the breeding season. No recent surveys have been completed. If these figures are still accurate, this represents approximately 1.3% of the global, 2.2% of the North Atlantic and about 9.5% of the eastern Canada Thick-billed Murre population. Historically, this site may have supported even larger numbers of murres. In 1957, approximately 400,000 pairs were estimated at this site. Large numbers of Black-legged Kittiwakes also nest at Cape Hay (provisional estimates of 20,000 pairs). This may represent from 7.6% to as much as 10% of the western Atlantic population of Black-legged Kittiwakes. This species may have also declined in numbers at Cape Hay. In 1957, 50,000 pairs were estimated at this site.
BirdLife International (2020) Important Bird Areas factsheet: Cape Hay. Downloaded from http://www.birdlife.org on 07/08/2020.