Common Black-headed Gull - Larus ridibundus

Common Black-headed Gull

Larus ridibundus

Order : Charadriiformes

Family : Laridae ;

Biometrics :

Size : 37 à 43 cm
Wingspan : 94 à 105 cm
Weight : 225 à 350 g

Longevity : 32 years

IUCN conservation status :

Extinct

Threatened

Least
concern

Extinc
in the Wild

Near
threatened

Not
evaluated

EX EW CR EN VU NT LC NE

Geographic range :

Synonyms : Ozernaya Chayka (ru), Skrattmås (sv), Gaviota reidora (es), Gabbiano comune (it), Lachmöwe (al), Kokmeeuw (nl), Common Black-headed Gull (en)

Physical description :
Black-headed Gull is an elegant aquatic bird. Both sexes are similar.
Breeding adult has pale grey back and upper wings. Outer primaries are white, with black tips. Leading edge is pure white, but it becomes black on the outermost primaries. Underside of primaries is dusky.
Black-headed Gull has chocolate-brown hood, which extends back to the ear and conspicuous white eye crescents.
Underparts are white, sometimes tinged with pale pink on the breast. Tail is white. Bill, legs and feet are blackish-red. Eyes are dark.
Adult in winter plumage has conspicuous dark spot behind the eyes. Dark hood disappears after breeding season. We can see two indistinct black bars across the crown, the first from eye to eye, and the other from ear to ear. Bill is red with black tip. Legs and feet are red.
Juvenile and immature have brownish tinge on head and upperparts. White tail has black tips. Bill is pale, flesh to yellow, with blackish tip. Legs and feet are paler than adults. They lack the dark hood. They reach their sexual maturity at two to three years.

Voice :
Sound from CD 'Tous les Oiseaux d'Europe' by Jean C. Roché by courtesy of Sittelle and CEBA. Black-headed Gull's usual call is a raspy 'tee-er'. They are very noisy birds, and short calls may be heard at colonies, and while they are quarrelling. They utter long squealing calls, and short repeated yapping notes.

Habitat : Black-headed Gull breeds in marsh edges, ponds and lakes, in clearings in boreal forest areas.
It winters in varied coastal habitats, from marine waters to harbours, salt marshes and estuaries. We can find it in towns, in urban parks with water.
GEOGRAPHIC RANGE: Black-headed Gull breeds in most part of Europe and Asia, and also in eastern Canada coasts. But this species can be seen now almost anywhere. It is resident in Western Europe areas, and some birds may winter in North-eastern United States.
Northern populations are migratory.

Behaviour : Black-headed Gull is highly gregarious outside breeding season. They feed and roost in large flocks. This bird is an opportunistic feeder. It scavenges in towns and beaches, or in ploughed fields. It follows a plough to snap up earth worms and other invertebrates. It also feeds while walking, swimming, and plunge-diving for fish when it follows fishing boats. It also flies along and plucks food from the surface.
Black-headed Gull nests in colonies, in grassy areas, reed beds and marshes, also on islands in lakes. It is very noisy at colonies.
Some quarrels may occur in colonies, and Black-headed Gull adopts special postures. The bird is aggressive when it stands in front of the opponent, displaying its dark hood. But submissive attitude shows the bird showing its pale nape, bowing head and neck for displaying its white nape. Other displays shows the bird in various postures: oblique display with erect posture; forwards displays with held neck, head in front of the body and horizontal bill; choking display, the bird leans towards the ground, bill downwards and uttering soft calls of short notes in rapid series.
Black-headed Gull is monogamous and faithful to its nest-site where it returns each year. It may nest in mixed groups with terns. Mating process culminates when male regurgitates food for female. Then, copulation occurs.

Flight : Black-headed Gull performs a quick and active flight. It can soar and glide, and even catching insects on the wing.

Reproduction-nesting : Black-headed Gull nests in large colonies, of up to 1000 pairs and more. Nests are at about one to five metres from each other.
It is a wide nest of about 50 cm of diameter. It is situated on the ground, or in low, moist vegetation. It is a shallow scrape lined with plant materials.
Colonies established in coastal marshes may be submerged by spring tides.
Female lays 2 to 3 olive-brown eggs, blotched with brown, in late April or early May. Incubation lasts about 22 to 26 days. Young fledge about 32 to 35 days after hatching, but they are semi-precocial and remain at nest about one week. They are covered with down.
This species produces only one brood per year, but they may start a second clutch until early July, if first is destroyed.

Food habits : Black-headed Gull feeds mainly on aquatic and terrestrial insects, marine invertebrates, fish, and earthworms. It also consumes fruits and seeds, refuse and various debris, and sometimes mice.

Protection / threats : Black-headed Gull populations are extending their range around the world, colonising little by little other countries, from middle latitudes of Europe and Asia, to the Sub-arctic area.
They have several predators such as crows, larger gulls, birds of prey, foxes and humans. But this species is not globally threatened.

Other links :
Iucn
Birdlife

Specification sheet created by Nicole Bouglouan

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