Cory's shearwater (''Calonectris borealis'') is a large shearwater in the

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 envir ...

family Procellariidae. It breeds colonially of rocky islands in the eastern Atlantic. Outside the breeding season it ranges widely in the Atlantic. It was formerly considered to be

conspecific Biological specificity is the tendency of a characteristic such as a behavior or a biochemical variation to occur in a particular species. Biochemist Linus Pauling stated that "Biological specificity is the set of characteristics of living organis ...

with Scopoli's shearwater.

Taxonomy

Cory's shearwater was formally described in 1881 by the American ornithologist Charles B. Cory from a specimen collected off Chatham Island, Massachusetts. He coined the

binomial name In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bo ...

''Puffinus borealis''. Cory's shearwater is now placed in the genus '' Calonectris'' that was introduced in 1915 by the ornithologists Gregory Mathews and

Tom Iredale Tom Iredale (24 March 1880 – 12 April 1972) was an English-born ornithologist and malacologist who had a long association with Australia, where he lived for most of his life. He was an autodidact who never went to university and lacked forma ...

. The genus name combines the

Ancient Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic pe ...

''kalos'' meaning "good" or "noble" with the genus name ''Nectris'' that was used for shearwaters by the German naturalist

Heinrich Kuhl Heinrich Kuhl (17 September 1797 – 14 September 1821) was a German naturalist and zoologist. Kuhl was born in Hanau (Hesse, Germany). Between 1817 and 1820, he was the assistant of professor Th. van Swinderen, docent natural history at the ...

in 1820. The name ''Nectris'' comes from the Ancient Greek ''nēktris'' meaning "swimmer". The specific epithet ''borealis'' is Latin and means "north". The species is considered to be

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispe ...

: no

subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics ( morphology), but that can successfully interbreed. Not all specie ...

are recognised. The Cape Verde shearwater ''C. edwardsii'' ( Oustalet, 1883) was once considered a subspecies of Cory's shearwater but has been split off as a separate species . It is

endemic Endemism is the state of a species being found 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 found else ...

to the Cape Verde Islands. It has an all dark, slim bill, and darker head and upperparts than Cory's. The flight has been described as rather more typically shearwater-like than the Cory's, with stiffer and more rapid wing beats. Scopoli's shearwater and Cory's shearwater were previously considered as

. They formed the Cory's shearwater complex (''Calonectris diomedea''). Based on the lack of hybridization and differences in mitochondrial DNA, morphology and vocalization, the complex was split into two separate species. The English name "Cory's shearwater" was transferred to ''Calonectris borealis'' while what was previously the

nominate subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics ( morphology), but that can successfully interbreed. Not all speci ...

became Scopoli's shearwater (''Calonectris diomedea'').

Description

This shearwater is identifiable by its size, at in length and with a wingspan. It has brownish-grey upperparts, white underparts and a yellowish bill. It lacks the brown belly patch, dark shoulder markings and black cap of the great shearwater.

Distribution and habitat

This species breeds on

Madeira ) , anthem = ( en, "Anthem of the Autonomous Region of Madeira") , song_type = Regional anthem , image_map=EU-Portugal_with_Madeira_circled.svg , map_alt=Location of Madeira , map_caption=Location of Madeira , subdivision_type=Sovereign st ...

, the

Azores ) , motto =( en, "Rather die free than subjected in peace") , anthem= ( en, "Anthem of the Azores") , image_map=Locator_map_of_Azores_in_EU.svg , map_alt=Location of the Azores within the European Union , map_caption=Location of the Azores wi ...

and the Berlengas Archipelago in

Portugal Portugal, officially the Portuguese Republic ( pt, República Portuguesa, links=yes ), is a country whose mainland is located on the Iberian Peninsula of Southwestern Europe, and whose territory also includes the Atlantic archipelagos of th ...

and the

Canary Islands The Canary Islands (; es, :es:Canarias, Canarias, ), also known informally as the Canaries, are a Spanish Autonomous communities of Spain, autonomous community and archipelago in the Atlantic Ocean, in Macaronesia. At their closest point to ...

Spain , image_flag = Bandera de España.svg , image_coat = Escudo de España (mazonado).svg , national_motto = '' Plus ultra'' (Latin)(English: "Further Beyond") , national_anthem = (English: "Royal March") , ...

Behaviour and ecology

This bird flies with long glides, and always with wings bowed and angled slightly back, unlike the stiff, straight-winged flight of the similarly sized great shearwater.

Breeding

They nest on open ground or among rocks or less often in 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 s ...

where one white egg is laid. The burrow is visited at night to minimise predation from large

gull Gulls, or colloquially seagulls, are seabirds of the family Laridae in the suborder Lari. They are most closely related to the terns and skimmers and only distantly related to auks, and even more distantly to waders. Until the 21st century ...

s. In late summer and autumn, most birds migrate into the Atlantic as far north as the south-western coasts of

Great Britain Great Britain is an island in the North Atlantic Ocean off the northwest coast of continental Europe. With an area of , it is the largest of the British Isles, the largest European island and the ninth-largest island in the world. It ...

and

Ireland Ireland ( ; ga, Éire ; Ulster-Scots: ) is an island in the North Atlantic Ocean, in north-western Europe. It is separated from Great Britain to its east by the North Channel, the Irish Sea, and St George's Channel. Ireland is the s ...

. They return to the Mediterranean in February. The biggest colony is located in

Savage Islands The Savage Islands or Selvagens Islands ( pt, Ilhas Selvagens ; also known as the Salvage Islands) are a small Portuguese archipelago in the North Atlantic Ocean, south of Madeira, and north of the Canary Islands.30,000), white-faced storm- ...

, Madeira.

Food and feeding

Cory's shearwater feeds on

fish Fish are Aquatic animal, aquatic, craniate, gill-bearing animals that lack Limb (anatomy), limbs with Digit (anatomy), digits. Included in this definition are the living hagfish, lampreys, and Chondrichthyes, cartilaginous and bony fish as we ...

mollusc Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is est ...

s and offal, and can dive deep ( or more) in search of prey. It readily follows fishing boats, where it indulges in noisy squabbles. This is a gregarious species, which can be seen in large numbers from ships or appropriate headlands. The

Bay of Biscay The Bay of Biscay (), known in Spain as the Gulf of Biscay ( es, Golfo de Vizcaya, eu, Bizkaiko Golkoa), and in France and some border regions as the Gulf of Gascony (french: Golfe de Gascogne, oc, Golf de Gasconha, br, Pleg-mor Gwaskogn), ...

ferries are particularly good for this species. It is silent at sea, but at night the breeding colonies are alive with raucous cackling calls.

Gallery

Calonectris borealis MHNT ZOO 2010 11 42 Ilha do Corvo Naurois.jpg, Egg from MHNT CorysShearwaterGroup.jpg, A group 200 nm east of

Cagarra Selvagem Pequena.jpg, Nest site on Selvagem Pequena Island Sepiasturmtaucher.jpg, Cory's Shearwater in flight Cory's shearwater (Calonectris borealis).jpg,

La Gomera La Gomera () is one of Spain's Canary Islands, located in the Atlantic Ocean off the coast of Africa. With an area of , it is the third smallest of the eight main islands of this archipelago. It belongs to the province of Santa Cruz de Tene ...

Cory's shearwater (Calonectris borealis) looking for fish, Corvo Island, Azores, Portugal (PPL1-Corrected) julesvernex2.jpg, Corvo,

Notes

References

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External links

Cory's Shearwater Species text in The Atlas of Southern African Birds

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