Justification This species qualifies as Vulnerable because it has a very small breeding range at three or four locations, and is therefore susceptible to stochastic events or human impacts. It is likely to have been extirpated from one island some time ago, but the bulk of the population is presumably stable.

Family/Sub-family Procellariidae

Species name author (Giglioli & Salvadori, 1869)

Taxonomic source(s) Brooke (2004), SACC (2005 + updates), Sibley and Monroe (1990, 1993), Stotz et al. (1996)

Identification 26 cm. Small, typical "M" marked gadfly petrel. Dark grey upperparts with sharp "M" mark. White forehead but dark grey cap and mask, extending to grey half-collar on upper breast. Dark grey rump and uppertail-coverts. Paler outer tail feathers. White throat and lower chest/belly. Predominantly white underwing, but black tip and narrow trailing edge, extending to leading edge. Similar spp. Separated from most other small gadfly petrels by whiter underwing. Cook's Petrel P. cookii has shorter and thinner bill and shorter tail. Stejneger's Petrel P. longirostris has paler crown and nape, and lacks darker central tail feathers. Pycroft's Petrel P. pycrofti is possibly inseparable, but ranges may not overlap.

Population estimate

Population trend

Range estimate (breeding/resident)

Country endemic?

10,000-19,999

unset

1,630,000 km²

Yes

Range & population Pterodroma defilippiana is an east Pacific seabird, currently breeding on three or four islands off the coast of Chile. In the Des Venturadas Islands, 10,000 or more birds occurred on San Ambrosio in 1970, with an additional 150-200 pairs on San Félix. In the Juan Fernández Islands, it has possibly been extirpated on Robinson Crusoe, and the population on Santa Clara was suggested at hundreds, possibly thousands, in 1986, but available habitat was found for only 100-200 individuals in 1991. It ranges at sea in the nearby Peru Current, south of the equator^4,6.

Ecology: It breeds on sheltered cliff-ledges, crevices, caverns and amongst boulders at the foot of lava cliffs. It nests colonially, with eggs apparently laid July-September, chicks hatching in October and colonies abandoned in December-January. However, it has been reported breeding in February on San Félix.

Threats Feral cats and coatis are blamed for the possible extinction on Robinson Crusoe, and cats have caused extensive mortality on San Félix. Rats have been cited as a predator but on which island is unknown. Santa Clara and San Ambrosio appear to be predator-free.

Conservation measures underway The Juan Fernández Islands were designated as a national park in 1935 (protected from 1967) and a biosphere reserve in 1977. The Chilean government began a habitat restoration programme in 1997⁷, and the islands have been nominated for World Heritage listing³.

Conservation measures proposed Remove all introduced mammals, initially within intensively managed, fenced, feasibility study areas. Survey to establish population size, local distribution and breeding productivity.

References Collar et al. (1992). 1. Giglioli and Salvadori (1869). 2. Howell et al. (1996). 3. Hulm (1995). 4. Roberson and Bailey (1991). 5. Sibley and Monroe (1990). 6. Spear et al. (1992). 7. J. C. Torres-Mura in litt. (1999).

Text account compilers Jeremy Bird (BirdLife International), David Capper (BirdLife International), Rob P Clay (Guyra Paraguay), Helen Temple (BirdLife International)

Contributors J. C. Torres-Mura

IUCN Red List evaluators Jeremy Bird (BirdLife International), Stuart Butchart (BirdLife International)

Recommended citation BirdLife International (2009) Species factsheet: Pterodroma defilippiana. Downloaded from http://www.birdlife.org on 9/2/2010

This information is based upon, and updates, the information published in BirdLife International (2000) Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004) Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.

To provide new information to update this factsheet or to correct any errors, please email BirdLife

To contribute to discussions on the evaluation of the IUCN Red List status of Globally Threatened Birds, please visit BirdLife's Globally Threatened Bird Forums