Gannets are great white sea birds easily recognizable by their unique diving methods. The sight of the Northern Gannet hunt is unlike any other, a sight that ranks among the greatest wildlife wonders to behold in the UK.
Here, wildlife photographer Richard Shucksmith presents his expert guide to gannets, with details on where to see them, how to identify them, anatomy, hunting techniques, what they eat and mating patterns.
Where do gannets live?
Favorite breeding grounds for gannets are towering cliffs on remote, windswept islands. Sheltered from large predatory mammals, these refuges are surrounded by the gannet’s favorite food: oily fish. Food is important for Northern Gannets: these birds carry a lot of fat, providing both insulation that saves them energy in icy waters and a reserve of fuel to tide them over in times of cold. lean cows.
Northern gannet colonies are also windy places, and the wind is particularly important for the northern gannet. Its long, narrow wings are adapted for foraging far out to sea, but they make landing and take-off difficult without the aid of the wind. The islands’ isolated cliffs provide strong updrafts, which the northern gannet uses to land and take flight.
Visiting a gannet cliff on foot offers a different experience. As you approach the edge of a cliff, even before you see the birds, the sound of thousands of gannets and the strong, pungent smell of guano hit your senses. Looking down from the top of the cliff, you see a swirling mass of gannets, like a throbbing giant white organism, encrusting the cliff.
Looking closely at the white-covered ledges, however, you will see an organization, a remarkable pattern of thousands of nests evenly spaced about 80cm apart – just enough to accommodate two large adults, including room for mutual display and a fat chick.
Gannets build substantial nests, often using seaweed to form the base. A sticky gelatin present in the algae makes it possible to stick the nest to the rock. The finished structure is approximately 30cm in diameter, with a nest in the middle. Grass and other materials floating in the sea are incorporated into the nest. It is rare today to find a gannet’s nest without some form of plastic, such as rope and old fishing nets. This causes problems – mainly tangling. It is not uncommon to see a gannet hanging from the cliff by a piece of rope and suffering a slow and painful death.
With adjacent nests so close together, collective noise and pair displays, from beak tapping to mutual preening, energize all birds, improving breeding success throughout the colony. This helps gannets lay their eggs early, so their young can fledge before winter storms.
Gannet Mating Patterns
Gannets mate for life and return to the same nest year after year. They lay an egg and both sexes incubate, taking around 44 days to hatch. The newborn chick is about 11 cm long and weighs 70-80 grams. Just 13 weeks later, the chick is eight times bigger at around 90cm long and – at over four kilos – more than 50 times heavier.
How do gannets hunt?
For the chick to reach this weight, gannets must feed on rich, seasonal fish such as herring, sand eels and, in particular, mackerel, which are rich in nutrients and oils. The latter are abundant on the coast from June to September.
Offshore, the northern gannet is practically the only seabird who feeds on them; only a gannet has the weight to dive deep enough to catch a mackerel, and the strength to handle these mighty fish.
The evolutionary adaptations required to catch these relatively large fish are remarkable. Gannets will dive from nine meters to 15 meters above the sea, reaching up to 60 mph when entering the water. Their wings fold backwards, turning their bodies into a narrow, streamlined shape, so they travel farther and faster through the water without their wings being damaged on impact.
To reduce the risk of impact injuries, head and neck airbags inflate, like airbags in cars. The gannet’s nostrils are fused, preventing water from entering the sinuses. They have binocular vision and the ability to adapt their sight by changing the shape of the lens in a split second to give them precise vision both above and below the waves to catch fish.
Diving only allows the bird to reach a few meters depth, but gannets can swim very well underwater, using both wings and legs to propel themselves, allowing them to dive even deeper, chasing fish down to about 30 meters.
Gannets have two types of dives: a V-shaped one, which lasts only a few seconds; the other U-shaped, in which the bird swims and can be submerged for about 20 seconds. The U-shaped dive is about 50% more efficient at catching prey.
Northern gannet migration
Having built their strength on fish, juvenile gannets migrate rapidly south up to 5,000 km, almost to the equator of West Africa. At the same time, adult gannets migrate towards the Mediterranean and as far as Morocco and Senegal.
Many species of British seabirds have fallen on hard times in recent decades as changes in sea temperature affect their food supply. Gannets, however, are a rare achievement. Northern gannet populations are increasing 3-5% per year, thanks to well-managed mackerel and herring stocks. The northern gannet now has a UK population of around 600,000 (240,000 breeding pairs). This is important internationally, comprising 60-70% of the world’s population.
All of this means that with luck, gannets will remain in the wild places of Britain for generations to come – and their vibrant, numerous and noisy colonies will continue to be one of the must-see places to visit for an unforgettable wildlife experience.
Anatomy of a Gannet
- Name: Gannet, Morus bassanus
- Size: the northern gannet is the largest in the UK seabird.
- Length: 87-100cm
- Wingspan: 165–180 cm
- Weight: 2.4 to 3.6 kg
- Lifespan: typically 17 years. The oldest known gannet is 37 years, four months and 16 days old, banding studies show.
- Gannets take five years to mature.
- Appearance: Both sexes are very similar in appearance. They have the eyes of birds of prey, their binocular vision enabling them to perceive depth. They are able to adapt their sight by changing the shape of the lens in a fraction of a second, giving them precise vision both above and below the waves to catch fish.
- Air sacs: Located in the head and neck, these inflate on inspiration to reduce the risk of impact injury.
- Nostrils: they are fused, preventing water from entering the sinuses.
- Wings: by folding their wings backwards (see opposite), bishops give their bodies a taut and streamlined shape (hydrodynamic) which prevents their wings from being damaged on impact with the surface and allows faster movement through water.
Where and when to see gannets
The best time to see gannet colonies is summer, from May to August.
- Troop Leader in Aberdeenshirewith 2,000 pairs.
- Bempton Cliffs on the Yorkshire Coastwith 13,000 pairs.
- Bass Rock is the largest gannet colony in the world with over 75,000 gannet pairs. It’s probably one of the easiest islands to visit, with boat trips organized by the Scottish Seabird Center in North Berwick, East Lothian, just 20 miles east of Edinburgh. seabird.org
- st kilda is a spectacular isolated archipelago 40 miles west-northwest of North Uist in the North Atlantic Ocean. It has over a million seabirds nesting on the islands with over 60,000 pairs of northern gannets and is the second largest colony. Several companies run boat trips to St Kilda, from the Isle of Harris, Uist and Skye.
- Grassholm National Nature Reserve in Pembrokeshire is home to 39,000 pairs of northern gannets, the third largest colony in the world. Several companies run boat trips to the island, including RSPB-accredited Thousand Island. ramseyisland.com
- Ailsa Craig in the Firth of Clyde is one of RSPB Scotland’s most spectacular and least accessible reserves, with 33,000 pairs of gannets. Boat trips depart from mainland Scotland and the Isle of Arran.
- Cliffs of Noup on Westray, Orkney, has 1,500 gannet pairs and is managed by the RSPB. The Orkney inter-island ferry takes you to Westray Island, where the settlement can be explored on foot.
How to Photograph Gannets
Trying to photograph a natural feeding frenzy of thousands of gannets diving over a school of fish proved impossible in the UK – so we photographers had to improvise.
Gannets have learned to follow fishing vessels, feeding on discards or bycatch – unwanted fish thrown overboard. So I imitated a fishing boat to create a gannet feeding frenzy. It was 10 years ago; the technique is now perfected. By building chutes that release fallen fish two or three meters below the surface, I can imitate schools of fish. I’ve tried several ways – hanging over the side of the boat, using a fishing rod, snorkeling and diving – and they all work. By far the most exhilarating thing is being myself in the water. Gannets dive incredibly close, within inches, but never reach me. I can get a wing in the face sometimes, but with the gannet’s ability to spot fish, I never get hit – it’s not in the booby’s best interest to hit an object while diving into the water. water.
Every summer I photograph and film this dramatic spectacle and help other photographers and film productions.