Northern gannet

Gannets live on the sea.

They come to cliffs and islands to make their nests.

Northern gannets live on both sides of the North Atlantic Ocean. They spend most of their lives at sea, mostly over the shallower waters of the continental shelf.

They nest on sea cliffs and islands in places such as eastern Canada, Iceland, Britain, Ireland, Norway and northern France. After the breeding season, many gannets fly south, and young birds go the farthest. Most of Britain's gannets spend the winter in the Bay of Biscay or farther south along West Africa, and a few cross the equator.

The IUCN describes a strictly marine species found on both sides of the Atlantic, wandering mostly over continental shelves, from Norway in the north to small numbers reaching the equator in the south, and up to 200 meters above sea level. It names breeding sites in northern France, the United Kingdom, Ireland, Iceland, Norway and the eastern tip of Quebec, Canada (del Hoyo et al. 1992).

Young birds migrate to the far south of the range, while adults range less widely but still regularly winter in the Mediterranean and the Gulf of Mexico. The BTO says most British gannets winter in the Bay of Biscay or farther south along West Africa, with some crossing the equator. In North America, Audubon's guide describes birds moving south off the Atlantic coast, some around Florida and along the Gulf Coast to Texas, with immatures wintering farther south than adults.

Gannets eat fish.

They fly high, then dive headfirst into the sea to catch them.

Northern gannets eat mostly small fish that swim in big groups called schools, such as herring, sand lance, cod, pollack and menhaden. They may also eat some squid.

To hunt, a gannet flies high and circles, then plunges headfirst into the sea, sometimes from more than 30 meters up. It can also hunt while swimming: it puts its head under the water to look for fish, then dives and swims after them. Sometimes they look for scraps around fishing boats.

The diet is mostly small schooling fish 2.5 to 30 centimeters long, including herring, sand lance, cod, pollack and menhaden, and perhaps some squid (Audubon guide, Kaufman 1996). The IUCN describes shoaling pelagic fish caught mostly by plunge-diving from great heights.

Audubon's account describes plunges headfirst from more than 30 meters (100 feet) above the surface, and a second method: swimming with the head submerged to look below, then diving and swimming underwater. Gannets may also take food at the surface, steal from other birds and scavenge scraps and offal around fishing boats; the IUCN notes that they attend trawlers and gather in large numbers where food is plentiful.

Gannets nest very close together.

Partners say hello by tapping their beaks together.

A gannet colony is crowded, noisy and smelly. The birds are packed so close that each one sits just out of reach of its neighbors' beaks, and there is a lot of competition for the best nest sites.

A male claims a nest spot and shakes his head from side to side to attract a mate. When partners meet, they stand face to face with their wings out, knock their bills together and bow. Gannets may stay with the same mate for life.

The BTO describes breeding colonies as noisy and pungent, with each bird just out of beak reach of its neighbors. Audubon's account (Kaufman 1996) notes strong competition for prime nest sites: the male claims a territory and displays to attract a mate with an exaggerated sideways shaking of the head, and mated pairs greet each other face to face, wings out, knocking bills together and bowing. Pairs may mate for life.

The call is a guttural croak or grunt, heard only on the breeding islands. The IUCN notes that gannets also gather in large numbers at sea where food is plentiful.

Long ago, people took many gannet eggs. Then gannets were protected, and there were more of them.

In 2022, bird flu made many gannets sick.

In the 1800s, gannet numbers fell sharply because people took their eggs and hunted the adults. With protection, they began to recover in the early 1900s. In Britain and Ireland, colonies grew by about 2% a year from 1969-70 to the last full count in 2013-15.

In 2022, bird flu reached gannet colonies. A count in 2023 using a drone found that Bass Rock in Scotland, the world's largest gannet colony, had shrunk from about 75,000 sites (each a spot held by one bird or a pair) to about 55,000. A 2026 study predicts that Bass Rock and Grassholm in Wales may not recover until 2041 at the earliest.

Audubon's account (Kaufman 1996) records a drastic 19th-century decline from egg collecting and the killing of adults, especially off eastern Canada, and recovery under protection from the early 20th century. BirdLife International assessed the species as Least Concern in 2018 (published 2018): 683,000 pairs in Europe (2015), which holds 75 to 94% of the range, give 1.5 to 1.8 million mature individuals, with an increasing trend. The IUCN says bycatch on longlines, set-nets and purse-seines is enough to cause significant declines; offshore wind farms pose a collision risk, though impacts appear limited so far. The BTO notes that colonies in Britain and Ireland grew about 2% a year from 1969-70 to 2013-15 (JNCC 2022), while a 2022 study found that warming seas and overfishing may be causing declines at Canada's southernmost colonies.

H5N1 bird flu was confirmed at Bass Rock on 4 June 2022. The Scottish Seabird Centre reported the colony down 25 to 30% on its 2014 count in 2023. An RSPB and Aarhus University study (2026) found that bird flu sharply raised the death rate of adults, that colonies shrank 26% at Bass Rock and 38% at Grassholm by 2023, and that recovery may not come before 2041; its authors recommend that the global status be revised.

Listen to the sound at the start of this page.

It is a real gannet colony on an island in Wales.

At the start of this page you can play a real recording of a northern gannet colony. It was made on Grassholm, an island off the coast of Pembrokeshire in Wales, in May 1965, and is kept by the British Library.

Audubon's guide describes the gannet's call as a throaty croak or grunt, heard only on the breeding islands.

The recording on this page was made by Lawrence Shove on Grassholm Island, off Pembrokeshire, Wales, in May 1965 (British Library, shelfmark W1CDR0001422 BD11, shared on Wikimedia Commons). Its notes describe a colony of northern gannets.

Audubon's account (Kaufman 1996) describes the call as a guttural croak or grunt heard only on the breeding islands. Grassholm is one of the two colonies in the RSPB-led bird flu study of 2026.