Wildlife Clinic

Species

Great shearwater

Ardenna gravis

A dark-capped shearwater that travels in a giant loop around the Atlantic, sometimes washing ashore on Georgia's beaches in early summer.

A great shearwater skimming low over calm blue water, its dark cap, white collar and long wings mirrored below.

Photo Paul Prior (opens in a new tab) / iNaturalist, CC BY 4.0 (opens in a new tab)

At a glance

Size
About 43 to 51 cm long; wingspan about 1 to 1.2 m
Weight
About 700 to 950 g
Habitat
Open ocean
Diet
Fish and squid
In Georgia
A common migrant offshore, May to July; sometimes found weak on beaches
Voice
Mostly silent at sea
Rabies vector
No

Identification

Key marks
Dark brown cap; white collar; dark bill; white underparts with a dark belly patch
Told apart from
Cory's shearwater, which is paler with a yellow bill
Where to look
Offshore in early summer; occasionally stranded on beaches

Behaviour

Great shearwaters breed on remote islands in the South Atlantic and travel in a giant loop through the North Atlantic during the southern winter. Young birds on their first migration sometimes come ashore exhausted.

Why they matter

Great shearwaters make one of the longest migrations of any seabird. When they wash ashore in numbers, it is a signal of hard conditions at sea, such as food shortages or storms.

Reproduction and lifecycle

Nest — A burrow on remote South Atlantic islands
Eggs — One
Incubation — About 55 days
Chick — Fed by both parents
Lifespan — Several decades

Living around people

  • A shearwater on the beach cannot take off from sand and should not be put back in the surf; it needs a rehabilitator.

Misconceptions

  • Seabirds on the beach are resting. A shearwater ashore is almost always exhausted, starving or injured.

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
NotesBreeding in the South AtlanticBreedingChicksMigrating northPassing off the SoutheastOffshore; some stranded on beachesNorth AtlanticNorth AtlanticMoving southMoving southReturning to breeding islandsBreeding

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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