The Juan Fernández petrel (''Pterodroma externa'') is a species of

seabird Seabirds (also known as marine birds) are birds that are adapted to life within the marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution, as the same enviro ...

in the family

Procellariidae The family Procellariidae is a group of seabirds that comprises the fulmarine petrels, the gadfly petrels, the diving petrels, the prions, and the shearwaters. This family is part of the bird order Procellariiformes (or tubenoses), which also ...

. It nests on a single island off the coast of Chile, in the

Juan Fernández Archipelago ''Juan'' is a given name, the Spanish and Manx versions of ''John''. It is very common in Spain and in other Spanish-speaking communities around the world and in the Philippines, and also (pronounced differently) in the Isle of Man. In Spanish, t ...

. It was previously classified as a subspecies of the

white-necked petrel The white-necked petrel (''Pterodroma cervicalis''), also known as the white-naped petrel, is a species of seabird in the family Procellariidae. During the non-breeding season it occurs throughout a large part of the Pacific, but it is only known ...

(''Pterodroma cervicalis''), which is found in tropical waters of the Pacific and Indian Oceans.

Description

The Juan Fernández petrel is a large species of

gadfly petrel The gadfly petrels or ''Pterodroma'' are a genus of about 35 species of petrels, part of the seabird order Procellariiformes. The gadfly petrels are named for their speedy weaving flight, as if evading gadflies (horseflies). The flight action is ...

, long with a wingspan of and a mass of . The upperparts are dark brownish-grey and there is a black M-shaped marking across the extended wings. The underparts are white, with the underside of the wing is edged black. The face is white, with a black "cap" extending below the eyes. The feet are yellow, dark brown at the tips. The bill is black with a hooked tip and houses the tubular nostrils that are unique to

Procellariiformes Procellariiformes is an order of seabirds that comprises four families: the albatrosses, the petrels and shearwaters, and two families of storm petrels. Formerly called Tubinares and still called tubenoses in English, procellariiforms are of ...

Behaviour

Breeding

Nesting

habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

is high elevation (above ) ridges, where it digs a

burrow An Eastern chipmunk at the entrance of its burrow A burrow is a hole or tunnel excavated into the ground by an animal to construct a space suitable for habitation or temporary refuge, or as a byproduct of locomotion. Burrows provide a form of sh ...

to raise one chick per year. Females lay a single, white egg in mid-November and both birds in a pair will take turns incubating the egg for about 60 days. The chick hatches in mid-February and is fed by both parents for 90–100 days before fledging in May. The chick remains underground in the burrow until it has reached fledgling mass and is fully feathered. Chicks are fed a diet consisting mainly of regurgitated fish and squid.

Distribution and status

During the breeding season, the petrels forage in waters surrounding Isla Alejandro Selkirk and Isla Robinson Crusoe (both islands in the

), as well as coastal Chile. The birds can be found in flocks with

pink-footed shearwater The pink-footed shearwater (''Ardenna creatopus'') is a species of seabird. The bird is in length, with a wingspan. It is polymorphic, having both darker- and lighter-phase populations. Together with the equally light-billed flesh-footed shea ...

s and other seabirds. During the non-breeding season, the petrels forage in the equatorial currents and counter-currents, as far north as the

Hawaiian Islands The Hawaiian Islands ( haw, Nā Mokupuni o Hawai‘i) are an archipelago of eight major islands, several atolls, and numerous smaller islets in the North Pacific Ocean, extending some from the island of Hawaii in the south to northernmost Kur ...

. It has been recorded as a vagrant in

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

, the

Chatham Islands The Chatham Islands ( ) (Moriori: ''Rēkohu'', 'Misty Sun'; mi, Wharekauri) are an archipelago in the Pacific Ocean about east of New Zealand's South Island. They are administered as part of New Zealand. The archipelago consists of about te ...

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

Fiji Fiji ( , ,; fj, Viti, ; Fiji Hindi: फ़िजी, ''Fijī''), officially the Republic of Fiji, is an island country in Melanesia, part of Oceania in the South Pacific Ocean. It lies about north-northeast of New Zealand. Fiji consists ...

, and the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

(in

Arizona Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Fou ...

and

Oregon Oregon () is a U.S. state, state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington (state), Washington, while the Snake River delineates much of it ...

). The petrel breeds only on one island in Chile, Isla Alejandro Selkirk. The breeding population was estimated at 1 million pairs in 1985–86, and there may be up to 3–5 million birds globally. It is threatened at its nesting sites by predation from introduced species (cats and rats) and, to a lesser extent, from

habitat loss Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...

caused by introduced herbivores (goats). The

IUCN Red List The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biol ...

lists the species as vulnerable due to its endemic status and threats from introduced predators.

References

*Brooke, M. 1987. Population estimates and breeding biology of the petrels ''Pterodroma externa'' and ''P. longirostris'' on Isla Alejandro Selkirk, Juan Fernandez Archipelago. The Condor. 89: 581–586.

External links

BirdLife species factsheet
{{Taxonbar, from=Q559959 Juan Fernández petrel Endemic fauna of the Juan Fernández Islands Alejandro Selkirk Island Robinson Crusoe Island Juan Fernández petrel Juan Fernández petrel Taxonomy articles created by Polbot