Gannet Diet and Size: Feeding Habits, Predators, and Measurements
The Gannet, or Morus bassanus, is one of the most remarkable seabirds, gracing the skies and coastlines of the UK with its distinctive white plumage, black wingtips, and yellowish head.
Known for their dramatic high-speed dives, Gannets are skilled hunters, plunging into the ocean to catch their prey.
In this article, let’s learn more about the dietary habits, size and weight, breeding behaviours, and threats facing these extraordinary birds!
Table of Contents
The Dietary Habits Of The Gannet
Gannets are skilled hunters of the sea, employing spectacular diving techniques to catch their prey.
What Does A Gannet Eat?
Gannets feed primarily on fish, including mackerel, herring, sprat, and sand eel. They are extraordinary hunters, diving from great heights to catch their prey underwater, using their long, pointed beaks to snatch fish.
These remarkable birds have several adaptations that make them efficient hunters. Their binocular vision helps them accurately judge distances when diving, while special air sacs under their skin protect them from impact when they hit the water. They can dive to depths of about 15 metres, though they typically hunt fish swimming near the surface.
During the breeding season, Gannets often hunt in groups, working together to herd fish into manageable shoals. This cooperative hunting behaviour increases their chances of successful catches and helps ensure they can provide enough food for their chicks.
What To Feed A Baby Gannet?
Baby Gannets, called chicks or gugas, are fed regurgitated fish by both parents. The parents take turns foraging and returning to the nest with partially digested fish, which they feed directly to their chick.
As the chicks grow, they receive whole fish rather than regurgitated food. This rich diet helps them build up the fat reserves they’ll need for their first migration.
Breeding Habits Of Gannets
The breeding season is a crucial time in the Gannet’s life cycle, marked by impressive displays and dedicated parental care.
Do Gannets Mate For Life?
Gannets are generally monogamous and tend to reunite with the same mate each breeding season. Their strong pair bonds are reinforced through mutual preening and shared responsibilities in nest building, incubation, and chick rearing.
Gannets typically lay a single egg each breeding season, and both parents share in the incubation process, which lasts around 40 to 45 days. This level of parental care ensures the chick receives adequate protection and sustenance throughout its development.
The Size & Weight Of Gannets
Gannets are impressive in size, being among the largest seabirds found in British waters.
How Much Does A Gannet Weigh?
Adult Gannets typically weigh between 2,400 to 3,600 grams (2.4 to 3.6 kg). Males are generally slightly heavier than females, though the difference is not always noticeable.
Their substantial weight provides the momentum needed for their powerful dives, while their streamlined body shape helps them cut through both air and water efficiently.
How Big Is A Gannet?
Gannets measure between 87 to 100 cm in length, with an impressive wingspan of 165 to 180 cm. This large wingspan allows them to soar effortlessly over vast distances during their foraging trips and migrations.
Their size makes them one of the largest seabirds in the North Atlantic, surpassed only by some species of albatross and large gulls. Their long, pointed wings and streamlined body shape are perfectly adapted for both sustained flight and high-speed diving.
Are Gannets Under Threat?
Gannets are currently listed as Amber on the UK Birds of Conservation Concern list.
Globally, they are classified as Least Concern on the IUCN Red List of Threatened Species, indicating stable populations.
What Eats A Gannet?
Due to their size and aggressive behaviour, adult Gannets have few natural predators. However, their eggs and young chicks are vulnerable to predation by larger birds such as gulls, which often target nests in densely packed colonies.
Additionally, on the rare occasions when Gannets venture near land, they can face threats from terrestrial predators such as foxes and cats.
Where Can I See Gannets In The UK?
The UK hosts internationally important breeding populations of Gannets. The largest colony is found at Bass Rock in the Firth of Forth, Scotland, home to over 75,000 breeding pairs. Other significant colonies can be found at Bempton Cliffs in Yorkshire, St Kilda in the Outer Hebrides, and Grassholm in Wales.
The best time to observe Gannets is during the breeding season, usually from March to September, when they gather at these colonies. However, they can be seen around the British coastline throughout the year, with some birds remaining in UK waters even during winter.
SEE ALSO: Gannet Life Cycle: Nest Building To Fledging (and everything in between)
Frequently Asked Questions
Gannets are remarkably long-lived birds, with an average lifespan of 17 years in the wild. Some individuals can live significantly longer, with records of birds reaching 37 years of age.
Gannets dive from heights of up to 30 metres to build up enough speed to catch fish swimming below the surface. Their streamlined body shape and special air sacs protect them from the impact when they hit the water.
Yes, many Gannets migrate south during winter, travelling to the Bay of Biscay or even as far as the West African coast. However, some birds remain in UK waters throughout the year.
