The storm-petrel (order Procellariiformes, family Hydrobatidae) is a small seabird (14-25 cm long) related to albatrosses and like them having nostrils encased in a tube. Storm-petrels are usually blackish with a white rump. The name petrel is probably derived from the English term "pitteral", meaning "walking elegantly," because of their habit of fluttering low over the waves, giving the impression of walking on water. Superstitious seamen, believing they warned of coming storms, called them Mother Carey's chickens, the birds which Mater Cara (Virgin Mary) sent to protect them.

The fork-tailed storm-petrel (Oceanodroma furcata) and Leach's storm-petrel (O. leucorhoa) breed in BC. Leach's also breeds in Atlantic Canada; its huge colonies in southeastern Newfoundland contain most of the North Atlantic population. Large numbers of Wilson's storm-petrel (Oceanites oceanicus) from Antarctica and Tierra del Fuego occur off Nova Scotia in summer.

Petrels nest in burrows on offshore islands, visiting these only at night. Introduced cats and rats have caused havoc in many colonies.