Black-capped petrel

The black-capped petrel (Pterodroma hasitata), also known as the diablotín, is a small seabird native to the West Indies in the genus Pterodroma. It is a long-winged petrel with a grey-brown back and wings, with a white nape and rump. Underparts are mainly white apart from a black cap (that in some individuals extends to cover the eye) and some dark underwing markings. It picks food items such as squid from the ocean surface.

The black-capped petrel is large compared to other gadfly petrels, with a length of about 16 inches (40.5 cm) and 37 inches (94 cm) wingspan. The most similar species within its range is the Bermuda petrel, which is smaller and has a narrower white rump patch and an extensive gray cowl. The great shearwater is also superficially similar. The critically endangered or possibly extinct Jamaica petrel (P. caribbaea) was a related dark form. The local Spanish name, Diablotín, means "little devil" because of its night-time habits and odd-sounding mating calls, which suggested to locals the presence of evil spirits in the dark. The petrel will occasionally utter other croaks and sounds while foraging at sea.

The black-capped petrel is nocturnal on its breeding grounds, possibly to avoid predation by gulls, hawks or crows. Like most petrels, its walking ability is limited to a short shuffle to the nest burrow.