Pterodroma externa: Juan Fernandez Petrel

Juan Fernandez Petrel - Pterodroma externa
( Salvin, 1875 )

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Subspecies:	Unknown
Est. World Population:

CITES Status:	NOT LISTED
IUCN Status:	Vulnerable
U.S. ESA Status:	NOT LISTED

Body Length:
Tail Length:
Shoulder Height:
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Top Speed:
Jumping Ability:	(Horizontal)

Life Span:	in the Wild
Life Span:	in Captivity

Sexual Maturity:	(Females)
Sexual Maturity:	(Males)
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Habitat:

The species is highly pelagic and rarely approaches land, except at breeding colonies. It nests in burrows on slopes in Dicksonia externa fern-forest, stands of low fern and adjacent grasslands and along open ridges at elevations of 600-1,150 m (J. C. Torres-Mura in litt. 1999, Hodum 2009, Reyes-Arriagada et al. 2012). One egg is laid in mid-December to early January (Hodum 2009) and chicks hatch in February-March (Hodum and Wainstein 2003). It is dependent on subsurface predators, especially Yellowfin Tuna Thunnus albacares, to drive prey to the surface (Au and Pitman 1986, Ballance et al. 1997).

Range:

Pterodroma externa breeds on Alejandro Selkirk Island in the Juan Fernández Islands, Chile. It is very numerous, but could be declining (Schlatter 1984), although there is no firm evidence of this (Brooke 2004). It is a transequatorial migrant, dispersing over the tropical and subtropical waters of the east Pacific, north to Hawaii (U.S.A.), and is regularly seen off the west coast of Mexico, with vagrants recorded to 42°N in the central Pacific (Howell 2012) and in New Zealand and east Australia (Carboneras 1992, Patterson 1996). Further information could indicate declines that would warrant uplisting.

Conservation:

Conservation Actions Underway The Juan Fernández Islands were designated a National Park in 1935 (protected from 1967) and a Biosphere Reserve in 1977 (Stattersfield et al. 1998, J. C. Torres-Mura in litt. 1999). The Chilean government began a habitat restoration programme in 1997 (J. C. Torres-Mura in litt. 1999), and the islands have been nominated for World Heritage listing (Hulm 1995). Reserve rangers have been trained in fighting fires, but there is only one ranger on Alejandro Selkirk (J. C. Torres-Mura in litt. 1999). Sheep were removed from Alejandro Selkirk in 1983 (Carboneras 1992). A goat eradication programme was unsuccessful. Population monitoring plots were established between 2003-2006 by Oikonos Ecosystem Knowledge (Hodum 2009). Oikonos also maintains an ongoing small-scale community conservation education programme in the islands, including on Alejandro Selkirk. Incipient invasive plant species are also being systematically eliminated from the island by Oikonos in collaboration with the Corporación Nacional Forestal (CONAF), the Chilean agency that administers the park.

Conservation Actions Proposed Establish population monitoring plots (M. de L. Brooke in litt. 1999). Improve sustainable management of yellowfin tuna stocks. Eradicate introduced fauna (goats, feral cats, rats, house mice, etc) from Alejandro Selkirk. Eradicate invasive and incipient invasive plant species from the island. Monitor effects of flash floods on colonies. Improve community awareness of the status of the species and the need for eradication programs. Improve management of cattle herds to ensure that it is excluded from potential breeding habitat.