Wildlife Clinic

Species

Cory's shearwater

Calonectris borealis

A large, pale-billed shearwater that glides over the Gulf Stream in summer, occasionally storm-driven toward shore.

A Cory's shearwater skimming low over blue sea on long, stiff wings, brown-grey above and white below with a pale yellow bill.

Photo Laura Gaudette (opens in a new tab) / iNaturalist, CC BY 4.0 (opens in a new tab)

At a glance

Size
About 45 to 56 cm long; wingspan about 1.1 m
Weight
About 560 to 1,000 g
Habitat
Warm offshore waters
Diet
Fish and squid
In Georgia
A common summer visitor far offshore
Voice
Mostly silent at sea
Rabies vector
No

Identification

Key marks
Large; brown-grey above, white below; pale yellow bill; slow, bowed-wing flight
Told apart from
Great shearwater, which has a dark cap, dark bill and white collar
Where to look
Far offshore in summer

Behaviour

Cory's shearwaters glide effortlessly over waves, rarely flapping. They breed on islands in the eastern Atlantic and Mediterranean.

Why they matter

Shearwaters travel huge distances by using the wind over the waves, and their numbers reflect the health of the open ocean. Their summer visits off Georgia connect the state to breeding islands off Europe and Africa.

Reproduction and lifecycle

Nest — A burrow or crevice on islands
Eggs — One
Incubation — About 52 to 55 days
Chick — Fed by both parents for about three months
Lifespan — Wild birds over thirty years are recorded

Living around people

  • A shearwater found on land cannot take off from flat ground; it needs a rehabilitator.

Misconceptions

  • A seabird on land just needs to rest. Shearwaters' legs are set far back and they struggle on land.

Related species

Seasonal activity

When this species is breeding, and when there are nests on the ground. Mowing during the shaded months is how most nests are found.

Breeding and active nests by month for this species
JanFebMarAprMayJunJulAugSepOctNovDec
BreedingJan: noFeb: noMar: noApr: noMay: noJun: noJul: noAug: noSep: noOct: noNov: noDec: no
Active nestsJan: noFeb: noMar: noApr: noMay: noJun: noJul: noAug: noSep: noOct: noNov: noDec: no
NotesOff South America and AfricaOffshore far southMoving northBreeding in the eastern AtlanticBreedingOffshore off the SoutheastOffshoreOffshoreOffshoreLeavingMoving southFar south

Where it lives

Recorded in 17 states and provinces. Each one links to the other animals there, and to the rehabilitators licensed for them.

If you found one

Answer a few questions and you will get a specific answer for what you are looking at.

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