No.057 · Birds · Common
Gannet
Morus bassanus
Britain's biggest seabird: a dazzling white bird with black wingtips that folds into a spear and plunges into the sea from height.
When to see a gannet
April to October, mostly at dawn and by day.
- J
- F
- M
- A
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Time of day
- Dawn
- Day
- Dusk
- Night
Where to see a gannet in the UK
- The Pembrokeshire coast. Watch offshore from Martin's Haven and the Marloes headlands; the birds fish over the sea between Skomer, Grassholm and the mainland.
Gannet facts at a glance
- Best time
- Spring to autumn, watching the sea from the headlands. In 2024 the count off Skomer peaked in September–October.
- Where in the game
- the Pembrokeshire coast (sea and clifftop)
- Size
- 87–100 cm
- Wingspan
- 170–180 cm
- Weight
- About 3 kg
- Lifespan
- Typically 17 years once breeding; oldest ringed bird 37 years (BTO)
- Population
- 295,000 nests in the UK (BTO, 2013–14). Grassholm, the biggest gannet colony in Wales, fell from 34,491 pairs in 2022 to 16,482 in 2023, a 52% drop after bird flu (RSPB Cymru census)
- Status
- Amber list, UK Birds of Conservation Concern (BTO); Red list in Wales since the 2024 review (Birds of Conservation Concern in Wales)
Diet
Shoaling fish such as mackerel and herring, caught in plunge dives
Habitat
Open sea; nests in dense colonies on cliffs and rocky islands
Breeding
One egg per year, incubated for 42–46 days by both parents. The chick fledges after 84–97 days
Field signs
- A huge white bird with black wingtips, cruising over the sea
- A sudden, steep dive that ends in a white splash
- A long neck and long, pointed bill and tail
- Yellowish head in adults; young birds are dark brown and speckled
Did you know?
- Grassholm, 11 miles off St David's Head, held about 6% of the world's gannets before 2022; bird flu then cut the colony by 52% in a year.
- A gannet's bill and skull are built to take the impact of plunge dives from height.
- On Skomer in 2024 the monthly gannet maximum peaked at 205 in September and 200 in October, then fell away in November, probably as Grassholm's birds left.
Moments worth waiting for
- Plunge-dive
A gannet circles high, folds its wings and drops like a spear, striking the water in a burst of white spray.
Photo tip
Sit on a headland facing the wind on a bright day, use 300–600 mm and pre-focus on the water where a bird has just folded its wings. Shoot bursts at 1/2000 s. Keep the sun over your shoulder for white feathers against a blue sea.
Be a good naturalist
Watch from the coast with binoculars. Do not approach the colony on Grassholm (landing needs permission) and keep boats well back. If you find a dead or sick seabird, do not touch it: report it, because bird flu has hit gannets hard.
The law
Protected as a wild bird under the Wildlife and Countryside Act 1981. Grassholm is an RSPB reserve and Special Protection Area
