Subspecies
Monotypic species
Genus
Genus Pterodroma, Pseudobulweria and Aphrodroma are also knwon as the Gadfly Petrels. They vary in size from rather small birds such as the Cookilaria-species, measuring about 26 cm, to the much larger and robust representatives of this group like the White-headed Petrel with an overall length of about 43 cm. Their plumages also vary a great deal from species to species; from completely black to light grey mantles and pure white bellies, and with different color phases within species. One feature shared by all of them is the black bill of which the shape also shows much variation. Some species are extremely rare and restricted to a very limited area, other are abundant and wander widely or have unknown pelagic ranges.
The group of the Gadfly Petrels counts over 35 species, mainly from the Southern Hemisphere. There are three genera: Pterodroma with about 30 species, Pseudobulweria counting four and Aphrodroma with only one. Many authors have tried to classify the large number of species of this group and to determine their relationships. This has resulted in a division in several subgenera and the grouping of several species which are considered to have a more or less close relationship. The taxonomic discussion has not come to an end yet: new species have been added or split recently and probably will be in the near future.
Physical charateristics
wingspan min.: | 89 | cm | wingspan max.: | 102 | cm |
size min.: | 40 | cm | size max.: | 42 | cm |
incubation min.: | 0 | days | incubation max.: | 0 | days |
fledging min.: | 0 | days | fledging max.: | 0 | days |
broods: | 1 | eggs min.: | 1 | ||
eggs max.: | 1 |
Range
Habitat
Reproduction
In early December, a cacophony of haunting screams and cries accompanies the adults as they return to the breeding colonies to begin nesting. Nests are made on a bed of plant debris within earth burrows or natural rock crevices. What happens next is poorly studied because of the relative inaccessibility of most breeding colonies. 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. During this time the nesting adult birds travel long distances back and forth from the colonies to the foraging sites
Feeding habits
The black-capped petrel forages predominantly in multispecies flocks throughout the night but with peak activity at dawn and dusk. While some time is spent foraging on the ocean surface, the preferred technique is to snatch items with their bills whilst in flight. 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
Conservation
Pterodroma hasitata now breeds in Haiti and the Dominican Republic. There are an estimated 1,000 breeding pairs, mostly in the Massifs de la Selle and de la Hotte, southern Haiti, but records at-sea suggest that the population is over 5,000 individuals. The area of suitable habitat in the Pic Macaya region of Massif de la Hotte is estimated to be 5 km2, with a similar area in La Visite, Massif de la Selle (the majority of colonies are found within a 10 km stretch spanning a 500 m elevational range on the north side of the ridge; two more colonies are located further to the east, span 5 km, again within a 500 m elevation range). Small numbers have been recently recorded on Dominica and in adjacent offshore waters, suggesting that it may still nest. It now seems likely that small numbers breed in Cuba based on observation in the Sierra Maestra region (a congregation of 40+ individuals in the vicinity of shoreline, vocalisations heard overhead by landbased observers, and evidence of birds moving inland). It is believed extinct on Guadeloupe (to France) (where common in the 19th century). Black-capped petrel may have bred on Martinique (to France). Even during the breeding season it is highly pelagic, with breeding condition birds recorded off the North Carolina coast, USA. Birds disperse over the Caribbean and Atlantic from the north-east USA to north-east Brazil, with four records in European waters, but the at-sea range has contracted in the north and west.
Migration
Distribution map
Literature
BLACK-CAPPED PETREL, PTERODROMA HAS/TATA, IN CUBA