Black-capped petrel (Pterodroma hasitata)
|Also known as:||Chanwan Lasél, Diablotín|
|Size||Length: 40 cm (2)|
Wingspan: 96 cm (3)
Classified as Endangered (EN) on the IUCN Red List (1).
Diablotin (little devil) was the name given to the black-capped petrel by the Caribbean islanders whose nights were commonly punctuated by the eerie calls of this now rare bird (3) (4). The back and upper surface of the wings of this medium-sized petrel are entirely black, as is the tip of tail. A white collar around the nape separates the black plumage of the back from that of the head, giving the impression of a black cap above the eyes. This distinctive black cap, for which the bird is named, is somewhat variable, and may in some individuals extend below the eyes (5). White uppertail coverts are equally conspicuous against the black of the back, wings and tail. Underneath, this petrel is almost entirely white, except for a black band bordering the edges of the wings (2) (3). It has a black, hooked bill, mostly pink legs and black feet (5) (6).
The only known extant black-capped petrel breeding populations are located in the highlands of Hispaniola, predominantly in southern Haiti but also in low numbers across the border in the Dominican Republic (7) (8) (9) (10). Historically, breeding populations were also recorded on several other Caribbean islands, including Martinique, Guadeloupe, Dominica and Cuba (4) (10) (11). It is almost certainly extinct on Martinique and Guadeloupe (4) but recent reports suggest the presence of breeding birds on Cuba (12). Its foraging range extends throughout the Caribbean and the Atlantic, but is observed most frequently on the western edge of the Gulf Stream from northeast South America to northeast USA (2) (3).
Nests are typically found along forested mountain slopes and cliffs at elevations from 1,500 metres up to 2,300 metres. During the non-breeding season, from approximately May to November, the black-capped petrel lives and forages at sea with the largest numbers concentrated around areas of nutrient rich upwelling (2) (3) (13).
In early December, a cacophony of haunting screams and cries accompanies the adults as they return to the breeding populations to begin nesting (3). Nests are made on a bed of plant debris within earth burrows or natural rock crevices (3) (10). What happens next is poorly studied because of the relative inaccessibility of most breeding populations. However, in common with other petrels, a single egg will undergo a lengthy incubation period before hatching, with the eventual fledging of young between late May and early June (3) (14). During this time the nesting adult birds travel long distances back and forth from the colonies to the foraging sites (2).
The black-capped petrel forages predominantly in multispecies flocks throughout the night but with peak activity at dawn and dusk (2) (3) (13). While some time is spent foraging on the ocean surface, the preferred technique is to snatch items with their bills whilst in flight (3) (13). Fish, squid and invertebrates all form part of the petrel’s diet, with fauna associated with Sargassum seaweed reefs being particularly popular. In addition, these birds are not averse to occasionally scavenge behind fishing vessels (2) (3) (13).
Up until the latter half of the 19th century, the black-capped petrel was relatively common within its breeding range (3) (10). Around this time, a burgeoning human population in the Caribbean islands and consequential habitat loss, harvesting for food and predation by introduced mammals, saw petrel numbers crash almost to the point of extinction. Indeed, for several decades prior to the early 1960s, the species appeared to have vanished completely. Fortunately, in 1963, an estimated 2,000 breeding pairs were discovered at the existing colonies in Haiti (7). It soon became evident, however, that these populations were under the same pressures that extirpated the breeding populations on other islands. By the turn of this century, the estimated number of breeding pairs had declined to 1,000, with a total population size of approximately 5,000 birds (3). Despite increased awareness, the population in Haiti is likely to continue to decline as a result of continued conversion of broadleaf forest to cropland and pasture at Parc La Visite. Sadly, this downward population trend on the breeding grounds may be further exacerbated by proposals to develop oil and gas fields within petrel foraging grounds off the coast of the USA (2) (15).
Most of the known black-capped petrel breeding populations occur within La Visite National Park and Pic Macaya National Park in Haiti, while Sierra de Baoruco National Park in the Dominican Republic also contains small populations (7) (8) (9) (10). However, despite official park status, the implementation of a sustainable conservation plan in Haiti’s two national parks has no measurable conservation effect due to political instability, corruption, absence of political will, and the abject poverty of the local population who depend critically on the forest for their day-to-day survival. Given that almost the world’s entire black-capped petrel breeding population occurs within these two parks, ensuring their protection presents the most critical challenge to conservation efforts (16). Current proposals for Haiti’s National Parks include establishing core ecological reserves that are strictly off-limits to humans, maintenance of defined park boundaries and long-term monitoring and research of avian populations (17) (18). However, with Haiti’s breeding populations still under threat, the presence of alternative nesting sites may be crucial to the species’ survival.
For further information on the black-capped petrel see:
- National Audubon Society:
- BirdLife International:
- U.S. Fish and Wildlife Service:
Authenticated (01/07/09) by James E. Goetz, Conservation Biologist, Cornell Laboratory of Ornithology.
- Coverts: small feathers concealing the bases of larger flight feathers, usually on the wings or tail.
- Extant: still occurring, not extinct.
- Incubation: the act of incubating eggs, that is, keeping them warm so that development is possible.
- Invertebrates: animals with no backbone.
IUCN Red List (November, 2011)