Great black-backed gull

Latin Larus marinus (L.)
Estonian Merikajakas

Also known as: the king of the Atlantic waterfront, swaabie

Status in Estonia

Breeding, migratory and wintering bird.

Description

The great black-backed gull is Estonia’s largest seagull. Has a thick neck, a very powerful beak, a blackish top side and a white underside. Up to 1.5 years of age, there is no black on the back, making it difficult to differentiate from other grey-feathered gulls. The colour of the featherless sections of the body varies gradually: a juvenile bird’s entirely black beak changes to a yellow beak with a red nostril patch and an adult bird’s eye changes from brown to yellowish grey. The legs are pink in every plumage.

Size

Body length 61–74 cm, wingspan 144–166 cm, body mass 1.2–1.8 kg.

Similar species

European herring gull, lesser black-backed gull.

Distribution

It is widespread on the North Atlantic and Baltic Sea coasts and islands. The Kola Peninsula in Russia and the area surrounding the White Sea have 3000–4000 breeding pairs. The distribution area also extends to North America. It is common on the coasts of Western and Northern Estonia as well as on open sea islets.

Population

Estonia has 1000–1500 breeding pairs.

Occurrence in Estonia

In the spring, it arrives at its nesting grounds in March and leaves usually by the end of November or early December. Between 500 and 1000 seagulls stay in Estonia to winter. They spend the winter on ice-free coasts and ports.

Diet

It is omnivorous (including bird eggs and chicks, carrion), but its main source of food is fish.

Habitat

It can only be seen at sea; it does not travel inland. Seagulls are almost always seen in large city ports, where they fly alongside lesser gulls to accompany ships. It breeds primarily on small sea islands far from the coast and to a lesser extent on high sea coastlines, on huge rocks near the coast and occasionally in coastal lagoons.

Nesting

The nest is commonly built near the island’s coastal zone by a rock; it prefers the parts of islands that stretch far into the sea. On a suitable rocky island with limited vegetation, seagull population density can exceed 60 pairs/ha in scattered colonies. The nest is a large (diameter 60–70 cm) mound of twigs, plants and algae lined with feathers on the inside. Towards the end of April, the female bird lays 2–3 eggs. Incubation begins after the first egg is laid and both parents incubate for 26–30 days. The chicks hatch at different times and are fed by both parents. The chicks grow a proper plumage after half a month and learn to fly between one and a half and two months old. However, the family stays together until flocking or migration to warmer climates in the autumn. Young seagulls start their families in their third year of life.

Conservation status and protection

Not under protection. The most serious threat is nests washing away and young drowning during increasing storms.

Distribution and population in Lääne County

The great black-backed gull is a common seagull species along the shore of Lääne County, but relatively uncommon here compared to rest of the world. Great black-backed gulls can be found on the seashore, inland bays and coastal lakes. In Matsalu National Park, they can be found at Keemu and Puise ports as well as Haeska and Põgari-Sassi. Great black-backed gulls are also common in Haapsalu and the Noarootsi region.
They often sit on large rocks, where they can be observed for a long time.