Trindade Petrel (Pterodroma arminjoniana)

Trindade Petrel

Subspecies

Genus	Species	subspecies	Region	Range
Pterodroma	arminjoniana		AO	sw

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

Medium-sized, polychromatic petrel (dark, pale and intermediate plumages) with diagnostic white patch on underwing at the bases of primary feathers.. Dark morph is wholly dark brown. Pale morph has very dark grey upperparts, white forehead-sides, and is white below with indistinct or well delimited grey breast-band. Black, deep and narrow bill, with strongly hooked nail, typical of the genus. Juvenile like adult. Dark morph is similar to Kermadec Petrel P. neglecta, but has pointed tail ,more white on underwing, but only separated from the Trindade petrel by absence of pale primary shafts in the upperwing and distinct call. Pale morph has less white on face and more on underwing than P. neglecta.

wingspan min.:	88	cm	wingspan max.:	102	cm
size min.:	35	cm	size max.:	39	cm
incubation min.:	50	days	incubation max.:	56	days
fledging min.:	95	days	fledging max.:	105	days
broods:	1		eggs min.:	1
			eggs max.:	1

Range

Atlantic Ocean : Southwest. Pterodroma arminjoniana breeds on Trindade and Martin Vaz Islands off the coast of Espirito Santo, Brazil. It was considered abundant on Trindade in 1913 and 1986

Habitat

Highly pelagic, during breeding found in the hilly parts of Trinidade. Sometimes breeds at sea level.

Reproduction

It breeds year-round (all months) in crevices and other cliff-cavities in the highest parts of Trindade but sometimes down to sea level. The peak times for breeding activities (laying) are October and April. Females lay 1 egg that is incubated for 53 days. Young are fledged at about 100 days old. Both parents incubate the egg and feed the young. They alternate incubation shifts of about 8 to 9 days long. Hatchlings are fed most frequently in their first 10 days, then less frequently through 75 days old, and much less frequently after that. Young are fed up to 138 grams of regurgitate at a feeding

Feeding habits

Little known, they have been observed eating squid and may eat primarily squid.

Video Trindade Petrel

httpv://www.youtube.com/watch?v=AnO0Rjq5_94

Conservation

This species has a very small breeding range and population on two groups of islands in the south Atlantic Ocean, where it is susceptible to human impacts and stochastic events. An unidentifed Pterodroma species breeding on Round Island in the Indian Ocean may refer to this species. If so, the species’s status would require re-evaluation.

Migration

No data.

Distribution map

Trindade Petrel distribution range map

Planet of Birds