Mascarene Petrel (Pseudobulweria aterrima)

Mascarene Petrel

Subspecies

Genus	Species	subspecies	Region	Range
Pseudobulweria	aterrima		IO	w

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, dark gadfly petrel. Dark chocolate-brown with slightly paler chin, upper throat and underwing. Black bill. Pink tarsi. Black feet, webs with pale patch towards base of inner web. Like Bulwer’s Petrel Bulweria bulwerii and Jouanin’s Petrel B. fallax but more robust, smaller with heavier bill, shorter tail and lacking wing-bar. Dark phase of Trindade Petrel Pterodroma arminjoniana has longer wings.

wingspan min.:	0	cm	wingspan max.:	0	cm
size min.:	34	cm	size max.:	38	cm
incubation min.:	0	days	incubation max.:	0	days
fledging min.:	0	days	fledging max.:	0	days
broods:	0		eggs min.:	0
			eggs max.:	0

Range

Indian Ocean : West. Pseudobulweria aterrima is known from Reunion (to France) and by subfossil remains on Rodrigues (Mauritius).

Habitat

All known breeding sites are on cliffs, presumably in heathy vegetation

Reproduction

Hardly any information. Recent data confirms austral summer breeding, with incubation around December, and fledging between February and March

Feeding habits

No data.

Conservation

This species is classified as Critically Endangered because it is assumed to have an extremely small breeding population and to be undergoing a continuing decline owing to predation and light-induced mortality. Effective conservation measures are urgently needed.
The few records include four specimens collected in the 19th century, two birds found dead in the 1970s, and rare observations of birds in the waters south of Reunion since 1964. Recently four more individuals, two of which died, were found attracted to urban lights of Reunion towns. Five breeding sites are known (9-10 pairs in total, including one loose colony with four pairs), all restricted to a small area which is unlikely to harbour more than c.40 breeding burrows in total. Data collected at sea during the period 1978-1995 indicates that the population is probably c.1,000 individuals with perhaps 45-400 pairs, although 50-100 pairs is probably more likely.

Mascarene Petrel status Critically Endangered

Migration

No data

Distribution map

Mascarene Petrel distribution range map

Planet of Birds