Overview

Black-capped Petrel: Large petrel with white underparts, dark brown to black back and upper wings, black cap, and white collar (this field mark is missing in some birds). Tail is long, dark, and wedge-shaped; underwings show broad dark margins. Hooked bill is dark, legs are pink. High arcing flight.

Black-capped Petrel: The Black-capped Petrel is a little-known seabird that is found at sea from northern South America to the southeastern U.S. Currently, the only known breeding colonies are located in the highlands of Hispaniola - on Massif de la Selle and Massif de la Hotte in Haiti and in the nearby Loma del Toro in the Dominican Republic. The total population is small, and a mere handful drift northward along the Gulf Stream in summer and fall, after the breeding season.

Voice Text

Generally silent

• Black-capped Petrels are also known as Diablotín, or "little devil” because of its night-time habits and odd-sounding mating calls, which reminded villagers of the sounds of evil spirits.
• They once bred on at least four islands in the Caribbean. Now they can only be heard reliably on the Island of Hispaniola. Hunting, habitat alteration, introduced predators and natural disasters have led to the extirpation of this species from much of its previous breeding range.
• Due to their prevalence off the coast of the U.S. some researchers believe that there are other breeding colonies not yet accounted for. Expeditions to find breeding birds in Cuba have been made, but no colonies have been found thus far. Likewise, reports of Black-capped Petrels in Dominica have not been followed by the discovery of other nesting sites.
• A group of petrels are collectively known as a "gallon" and a "tank" of petrels.

• Greater Shearwater
• Dark-rumped Petrel
• Mottled Petrel
• Bermuda Petrel
• Fea's Petrel

Petrels and Shearwaters (Procellariidae)

ORDER

There are four families of seabirds in the PROCELLARIIFORMES (pronounced pro-sel-lehr-EYE-ih-FOR-meez), an order that includes the dainty storm-petrels, the huge albatrosses, and the shearwaters.

FAMILY TAXONOMY

The shearwaters are in the Procellariidae (pronounced pro-sel-lar-EYE-ih-dee), a family composed of eighty-five species in fourteen genera that roam all oceans of the world.

NORTH AMERICA

In North American waters, thirty-five species of shearwaters in six genera have been identified. Included among these are the thin-winged Pterodrama species of the deep waters such as the Black-capped Petrel, and the stocky, gull-like Northern Fulmar.

KNOWN FOR

Shearwaters are known for the prominent tube-like structures on their beaks that, as with all Procellariiformes, help remove excess sea water. Species such as the Sooty and Short-tailed Shearwaters are also known for their open water, low altitude gliding and tilting mode of flight on straight wings, the tips of which often slice or “shear” through the water’s surface.

PHYSICAL

Shearwaters are seabirds that are medium to large in size with elongated round bodies, medium length tails, long, pointed wings, and webbed feet adapted to their marine environment. Their bills are medium length, narrow, have a small hook on the tip, and are topped with tubular nasal structures.

COLORATION

This dull-colored family is plumaged in dark browns, black, white, and gray. Some species such as the Sooty Shearwater are all dark with silvery wing linings, while others such as the Great Shearwater are dark above and light below. The Black-capped Petrel and related species have gray and white plumage with bold black markings on the head, back, and wings.

GEOGRAPHIC HABITAT

Shearwaters are encountered in deep, marine waters off of both coasts with the deepest waters beyond the continental shelf favored by the petrels of the Pterodrama genus. They only occur on fresh water if blown inland by hurricanes, and on land are only likely to be encountered on northern cliffs and islets that are their breeding grounds.

MIGRATION

Some species undertake very long migrations from breeding areas in the Southern Hemisphere to the waters of the Northern Hemisphere.

HABITS

Shearwaters nest in colonies, and often occur in flocks when foraging. Fish, squid, crustaceans, and other food items are sometimes picked from the surface, but mostly obtained by diving into the water.

CONSERVATION

Populations of several species of shearwaters have been declining with subsequent listing as near-threatened or threatened; these declines likely linked to long-line fishing and global warming. Shearwaters are also easily threatened by disturbances at their breeding grounds.

INTERESTING FACTS

Shearwaters produce an oily substance in their stomachs that is fed to young and which can be vomited as a defense mechanism. Young birds high in fat and oil content are harvested by the Maori people in New Zealand where they are called, “muttonbirds”.

Author

Gary Owen Dick

Artist

Samira Belous