The shearwater (order Procellariiformes, family Procellariidae) is a medium-sized seabird (up to 50 cm long) related to the albatross and fulmar. Shearwaters are all dark or dark above and white below. They breed in large colonies which they visit only at night, and lay their single, white eggs in burrows.

Only the Manx shearwater (Puffinus puffinus) breeds in Canada, in a small colony in Newfoundland. However, large numbers of Southern Hemisphere shearwaters visit Canadian waters in summer. Short-tailed shearwaters (P. tenuirostris) from Tasmania and sooty shearwaters (P. griseus) from New Zealand and Tierra del Fuego occur off BC. Some sooties and the world population of greater shearwaters (P. gravis) from Tristan da Cunha come up to Newfoundland waters; these migrants probably outnumber the local breeding population of seabirds.

Shearwaters feed on squid, capelin, herring and swarms of crustaceans, and scavenge from fishing boats.