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

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 ...

in the

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

family

Procellariidae The family (biology), family Procellariidae is a group of seabirds that comprises the fulmarine petrels, the gadfly petrels, the diving petrels, the prion (bird), prions, and the shearwaters. This family is part of the bird order (biology), orde ...

. It breeds colonially on the archipelago of the

Azores The Azores ( , , ; , ), officially the Autonomous Region of the Azores (), is one of the two autonomous regions of Portugal (along with Madeira). It is an archipelago composed of nine volcanic islands in the Macaronesia region of the North Atl ...

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 organism ...

with

Scopoli's shearwater Scopoli's shearwater (''Calonectris diomedea'') is a seabird in the petrel family Procellariidae. It breeds on rocky islands and on steep coasts in the Mediterranean but outside the breeding season it forages in the Atlantic. It is brownish grey ...

Taxonomy

Cory's shearwater was

formally described A species description is a formal scientific description of a newly encountered species, typically articulated through a scientific publication. Its purpose is to provide a clear description of a new species of organism and explain how it differ ...

in 1881 by the American ornithologist Charles B. Cory from a specimen collected off

Chatham Island Chatham Island ( ) ( Moriori: , 'Misty Sun'; ) is the largest island of the Chatham Islands group, in the south Pacific Ocean off the eastern coast of New Zealand's South Island. It is said to be "halfway between the equator and the pole, a ...

, Massachusetts. He coined the

binomial name In taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin grammatical forms, altho ...

''Puffinus borealis''. Cory's shearwater is now placed in the genus ''

Calonectris ''Calonectris'' is a genus of seabirds. The genus name comes from Ancient Greek ''kalos'', "good" and ''nectris'', "swimmer". The genus comprises four large shearwaters. There are two other shearwater genera, ''Puffinus'', which comprises 21 sm ...

'' that was introduced in 1915 by the ornithologists

Gregory Mathews Gregory Macalister Mathews CBE FRSE FZS FLS (10 September 1876 – 27 March 1949) was an Australian-born amateur ornithologist who spent most of his later life in England. Life He was born in Biamble in New South Wales the son of Robert H. M ...

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 Autodidacticism, autodidact who never went to university ...

. The genus name combines the

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

''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 people, 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 of natural ...

in 1820. The name ''Nectris'' comes from the Ancient Greek word ''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 "unisp ...

: no

subspecies In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...

are recognised. The

Cape Verde shearwater The Cape Verde shearwater (''Calonectris edwardsii''), or cagarra locally, is a medium-large shearwater, a seabird in the petrel family Procellariidae. It is endemic to the Cape Verde archipelago of Macaronesia in the Atlantic Ocean, off the coa ...

''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 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 ...

to the

Cape Verde Islands Cape Verde or Cabo Verde, officially the Republic of Cabo Verde, is an island country and archipelagic state of West Africa in the central Atlantic Ocean, consisting of ten volcanic islands with a combined land area of about . These islands ...

and 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.

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 (: 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. ...

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 Madeira ( ; ), officially the Autonomous Region of Madeira (), is an autonomous Regions of Portugal, autonomous region of Portugal. It is an archipelago situated in the North Atlantic Ocean, in the region of Macaronesia, just under north of ...

, the

and the

Berlengas The Berlengas are a Portuguese archipelago consisting of small Atlantic islands off the coast of Peniche, Portugal, in the Oeste region. These islands were traditionally known to British mariners as "the Burlings". The only inhabited island is ...

Archipelago in

Portugal Portugal, officially the Portuguese Republic, is a country on the Iberian Peninsula in Southwestern Europe. Featuring Cabo da Roca, the westernmost point in continental Europe, Portugal borders Spain to its north and east, with which it share ...

and the

Canary Islands The Canary Islands (; ) or Canaries are an archipelago in the Atlantic Ocean and the southernmost Autonomous communities of Spain, Autonomous Community of Spain. They are located in the northwest of Africa, with the closest point to the cont ...

Spain Spain, or the Kingdom of Spain, is a country in Southern Europe, Southern and Western Europe with territories in North Africa. Featuring the Punta de Tarifa, southernmost point of continental Europe, it is the largest country in Southern Eur ...

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 The great shearwater (''Ardenna gravis'') is a large shearwater in the seabird family Procellariidae. It breeds colonially on rocky islands in the south Atlantic. Outside the breeding season it ranges widely in the Atlantic. Taxonomy The great s ...

Breeding

They nest on open ground or among rocks or less often in a

burrow file:Chipmunk-burrow (exits).jpg, 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 Animal lo ...

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 subfamily Larinae. They are most closely related to terns and skimmers, distantly related to auks, and even more distantly related to waders. Until the 21st century, most gulls were placed ...

s. In late summer and autumn, most birds

migrate Migration, migratory, or migrate may refer to: Human migration * Human migration, physical movement by humans from one region to another ** International migration, when peoples cross state boundaries and stay in the host state for some minimum le ...

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 north-west coast of continental Europe, consisting of the countries England, Scotland, and Wales. With an area of , it is the largest of the British Isles, the List of European ...

and

Ireland Ireland (, ; ; Ulster Scots dialect, Ulster-Scots: ) is an island in the North Atlantic Ocean, in Northwestern Europe. Geopolitically, the island is divided between the Republic of Ireland (officially Names of the Irish state, named Irelan ...

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

Savage Islands The Savage Islands or Selvagens Islands ( ; also known as the Salvage Islands) are a small Portugal, Portuguese archipelago in the North Atlantic Ocean, south of Madeira and north of the Canary Islands.30,000), white-faced storm-petrel (>80,0 ...

, Madeira.

Food and feeding

Cory's shearwater feeds on

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 ...

mollusc Mollusca is a phylum of protostome, protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant taxon, extant species of molluscs are recognized, making it the second-largest animal phylum ...

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 ( ) is a gulf of the northeast Atlantic Ocean located south of the Celtic Sea. It lies along the western coast of France from Point Penmarc'h to the Spanish border, and along the northern coast of Spain, extending westward ...

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 Selvagem Pequena Island () is an island in the southeast group of the Savage Islands, Madeira, Portugal Portugal, officially the Portuguese Republic, is a country on the Iberian Peninsula in Southwestern Europe. Featuring Cabo da Roca, the ...

Sepiasturmtaucher.jpg, Cory's Shearwater in flight Cory's shearwater (Calonectris borealis).jpg,

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

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

Notes

References

* * * *

External links

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

* * * * * *