The Galápagos shearwater (''Puffinus subalaris'') is a small

shearwater Shearwaters are medium-sized long-winged seabirds in the petrel family Procellariidae. They have a global marine distribution, but are most common in temperate and cold waters, and are pelagic outside the breeding season. Description These tube ...

. Until recently it was considered to be a subspecies of

Audubon's shearwater The Sargasso shearwater (''Puffinus lherminieri'') is a small Tropics, tropical seabird in the Procellariidae, petrel family (biology), family. The only shearwater to nest primarily in the Caribbean, it ranges throughout the western Atlantic duri ...

, but it is actually one of two members of a very ancient lineage of the small ''Puffinus'' species, the other being, as indicated by

mtDNA Mitochondrial DNA (mtDNA and mDNA) is the DNA located in the mitochondria organelles in a eukaryotic cell that converts chemical energy from food into adenosine triphosphate (ATP). Mitochondrial DNA is a small portion of the DNA contained in ...

cytochrome ''b''

sequence In mathematics, a sequence is an enumerated collection of objects in which repetitions are allowed and order matters. Like a set, it contains members (also called ''elements'', or ''terms''). The number of elements (possibly infinite) is cal ...

data, the

Christmas shearwater The Christmas shearwater or ''aoū'' (''Puffinus nativitatis'') is a medium-sized shearwater of the tropical Central Pacific. It is a poorly known species due to its remote nesting habits, and it has not been extensively studied at sea either. ...

. It is an

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

breeder of the

Galápagos Islands The Galápagos Islands () are an archipelago of volcanic islands in the Eastern Pacific, located around the equator, west of the mainland of South America. They form the Galápagos Province of the Republic of Ecuador, with a population of sli ...

, and is largely sedentary, although individuals are commonly seen as far as the

Oaxaca Oaxaca, officially the Free and Sovereign State of Oaxaca, is one of the 32 states that compose the political divisions of Mexico, Federative Entities of the Mexico, United Mexican States. It is divided into municipalities of Oaxaca, 570 munici ...

n coast of

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

Description

The Galápagos shearwater has dark brown upperparts, undertail and underwing flight feathers, the rest of the underparts

plumage Plumage () is a layer of feathers that covers a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage differ between species and subspecies and may vary with age classes. Within species, there can b ...

being white. It sometimes has a dark collar. Both sexes are alike, as are the young after

fledging Fledging is the stage in a flying animal's life between hatching or birth and becoming capable of flight. This term is most frequently applied to birds, but is also used for bats. For altricial birds, those that spend more time in vulnerable c ...

. It is a slender-bodied shearwater, about 29–31 cm long, with a wingspan of around 63 cm and weighs 123-225 g. The species closely resembles the tropical shearwater, although the latter is typically blacker and has a longer tail.Onley, and Scofield, ''Albatrosses, Petrels and Shearwaters of the World'' (Helm 2007)

Behaviour

The Galápagos shearwater is a gregarious species and will feed at sea with other shearwaters and

boobies A booby is a seabird in the genus ''Sula'', part of the family Sulidae. Boobies are closely related to the gannets (''Morus''), which were formerly included in ''Sula''. Systematics and evolution The genus ''Sula'' was introduced by the Fre ...

. It flies low over the water and feeds on

squid A squid (: squid) is a mollusc with an elongated soft body, large eyes, eight cephalopod limb, arms, and two tentacles in the orders Myopsida, Oegopsida, and Bathyteuthida (though many other molluscs within the broader Neocoleoidea are also ...

fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

and offal. It intersperses 4-10 stiff wing beats with shallow glides.

References

External links

Galapagos shearwater photos
{{Taxonbar, from=Q1271926 Puffinus Shearwaters Endemic birds of the Galápagos Islands Galápagos Islands coastal fauna Birds described in 1897 Taxa named by Robert Ridgway