Great shearwater

How it lives

Great shearwaters breed in large colonies, in burrows or in open grass, and visit the nests only at night. They lay one white egg. At Tristan da Cunha birds return to the colonies in late August, lay in November, hatch chicks in January and fledge them in May. Great shearwaters are gregarious and make a piercing cry when resting in groups on the water.

Where it goes

A full migrant that breeds in the South Atlantic and spends the northern summer in the North Atlantic. Adults begin the journey in April, moving north-west to South America, then on to Canada, past Greenland and into the north-east Atlantic, before returning south in November. Most birds reach waters off Newfoundland and Greenland in June and July. Off Britain and Ireland they are seen mostly in August and September, with most records from the south-west of England.

We only draw a journey on the map when scientists have tracked it or clearly documented it. For this animal we have not found one yet.

Populations

IUCN (2018): Least Concern, with the population suspected to be stable. A 2004 estimate gave at least 15 million individuals. IUCN cites at least 5 million pairs at Tristan da Cunha and 600,000 to 3 million pairs at Gough. A 2015 survey of Nightingale Island estimated about 1.82 million pairs (95% range 1.67 to 1.97 million), and a Tristan da Cunha page gives 2 to 3 million pairs there, 2 million on Inaccessible and 1 million on Gough. IUCN notes high bycatch in Atlantic fisheries. Several thousand adults and about 50,000 chicks are harvested each year from Nightingale Island by islanders, and IUCN says sustainable levels are not known. Plastic ingestion is also reported. It is Green listed in the UK.