Black-headed Gull (Larus ridibundus)

From CopperWiki

Jump to: navigation, search


[edit] Black-headed Gull (Larus ridibundus) Linnaeus, 1766

The black-headed gull’s common name is somewhat misleading, in that its head is not black, but dark brown, but from a distance it’s looks black. It’s also known as laughing gull due to its call that sounds like its laughing.

[edit] Taxonomy

The black-headed gull belongs to the family Laridae. They are most closely related to the terns (family Sternidae). Most gulls belong to the large genus Larus.

Class: Aves
Order: Charadriiformes
Family: Laridae
Genus: Larus
Species: L. ridibundus Linnaeus, 1766

[edit] Distribution

The black-headed gull has historically been confined to Iceland and Eurasia. The black headed gull breeds in northern portions of Europe and Asia south to their southern parts; winters from the southern portions of the breeding range south to Africa and southern Asia. But this species can be seen now almost anywhere.

[edit] Physical Characteristics

Black-headed Gull is an elegant aquatic bird. They are relatively small, measuring 35-38 cm in length. 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. Under parts 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. Black-headed Gull performs a quick and active flight. It can soar and glide, and even catching insects on the wing.

[edit] 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 harbors, salt marshes and estuaries. We can find it in towns, in urban parks with water.

[edit] Diet

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.

[edit] Behavior

Black-headed Gull is highly gregarious outside breeding season. They feed and roost in large flocks. This bird is an opportunistic feeder. 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. They are 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.

[edit] See Also

[edit] Breeding

These gulls nest in colonies, within which pairs defend small territories. 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. They will defend these territories from other birds using ritualized displays. Two to three eggs are produced which are incubated for up to 22-26 days. After a further 32-35 days the chicks will have fledged. Black-headed gulls are fairly long lived, with a maximum recorded life-span of 32 years

[edit] References

  • The gulls (Laridae) of the world : their plumages, moults, variations, relationships and distribution. Bulletin of the AMNH ; v. 52, article 3.
  • The Clements Checklist of Birds of the World: James F. Clements, Jared Diamond, John W. Fitzpatrick.
  • Wetlands International Waterbird Population Estimates - Fourth Edition.
  • Ali, S. & Ripley, D. (1964-74 ) Handbook of the Birds of India & Pakistan (Vols. 1-10). Bombay: OUP
  • Grimmet, R Inskipp, T., & Inskipp, C. (1998) Birds of the Indian Subcontinent. UK: A&C Black.
  • Inskipp, T. et al. (1996) An Annotated Checklist of the Birds of the Oriental Region. Sandy, UK: OBC.
  • Kazmierczak, K. & van Perlo, B. (2000) A Field-Guide to the Birds of the Indian Subcontinent. UK: Pica Press
  • BirdLife International (2004
  • IUCN Red List of Threatened Species. IUCN 2006
  • Harrison, Peter (1988): Seabirds (2nd edition). Christopher Helm, London
  • Peterson, R.T., Mountfort, G. & Hollom, P.A.D. (1993) Collins Field Guide- Birds of Britain and Europe.