Hartlaub's gull (''Chroicocephalus hartlaubii''), also known as the king gull, it is a small

gull Gulls, or colloquially seagulls, are seabirds of the family Laridae in the suborder Lari. They are most closely related to the terns and skimmers and only distantly related to auks, and even more distantly to waders. Until the 21st century, m ...

. It was formerly sometimes considered to be a subspecies of the

silver gull The silver gull (''Chroicocephalus novaehollandiae'') is the most common gull of Australia. It has been found throughout the continent, but particularly at or near coastal areas. It is smaller than the Pacific gull (''Larus pacificus''), which ...

(''C. novaehollandiae''), and, as is the case with many gulls, it has traditionally been placed in the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

Larus ''Larus'' is a large genus of gulls with worldwide distribution (by far the greatest species diversity is in the Northern Hemisphere). Many of its species are abundant and well-known birds in their ranges. Until about 2005–2007, most gulls ...

'' but is now placed in the genus ''

Chroicocephalus ''Chroicocephalus'' is a genus of medium to relatively small gulls which were included in the genus '' Larus'' until recently. Some authorities also include the Saunders's gull in ''Chroicocephalus''. The genus name '' Chroicocephalus'' is from ...

''. The species’ name commemorates the German physician and zoologist,

Gustav Hartlaub Karel Johan Gustav Hartlaub (8 November 1814 – 29 November 1900) was a German physician and ornithologist. Hartlaub was born in Bremen, and studied at Bonn and Berlin before graduating in medicine at Göttingen. In 1840, he began to study and co ...

Description

Hartlaub's gull is 36–38 cm in length. It is a mainly white gull with a grey back and upperwings, black wingtips with conspicuous white "mirrors", and a dark red bill and legs. When breeding it has a very faint lavender grey hood, but otherwise has a plain white head. Sexes are similar. This species differs from the slightly larger

grey-headed gull The grey-headed gull (''Chroicocephalus cirrocephalus''), also known as the gray-hooded gull, is a small species of gull which breeds patchily in South America and Africa south of the Sahara. It is not truly migratory, but is more widespread i ...

in its thinner, darker bill, deeper red legs, paler, plainer head, and dark eyes. It takes two years to reach maturity. Juvenile birds have a brown band across the wings. They differ from same-age grey-headed gulls in that they lack a black terminal tail band, less dark areas in the wings, darker legs, and a white head.

Distribution and habitat

The gull is a

non-migratory Bird migration is the regular seasonal movement, often north and south along a flyway, between breeding and wintering grounds. Many species of bird migrate. Migration carries high costs in predation and mortality, including from hunting by ...

breeding resident endemic to the

Atlantic Ocean The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...

coastline of

South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countri ...

and

Namibia Namibia (, ), officially the Republic of Namibia, is a country in Southern Africa. Its western border is the Atlantic Ocean. It shares land borders with Zambia and Angola to the north, Botswana to the east and South Africa to the south and ea ...

. Although it is predominantly coastal or estuarine, it is not a pelagic species, and is rarely seen at sea far from land. About one half of the total population, currently estimated at about 30 000 birds, lives within the Greater

Cape Town Cape Town ( af, Kaapstad; , xh, iKapa) is one of South Africa's three capital cities, serving as the seat of the Parliament of South Africa. It is the legislative capital of the country, the oldest city in the country, and the second largest ...

area. It has accommodated well to humans, and can become very tame around habitations. Although it is a relatively rare species, about the tenth rarest of the world's 50 or so gull species, it is common in its range and is widely regarded in Cape Town as a nuisance, fouling buildings and bathing in urban ponds. It has, at times, been a hazard to aircraft near airports.

Behaviour

Like most gulls, Hartlaub's is highly gregarious in winter, both when feeding or in evening roosts. This is a noisy species, especially at colonies. The call is a raucous

crow A crow is a bird of the genus ''Corvus'', or more broadly a synonym for all of ''Corvus''. Crows are generally black in colour. The word "crow" is used as part of the common name of many species. The related term "raven" is not pinned scientifical ...

-like ''kaaarrh''. This species is frequently the subject of complaints about the noise it makes in urban areas.

Breeding

Hartlaub's gull breeds in large colonies, and the main traditional breeding colony for the Cape Town area is on

Robben Island Robben Island ( af, Robbeneiland) is an island in Table Bay, 6.9 kilometres (4.3 mi) west of the coast of Bloubergstrand, north of Cape Town, South Africa. It takes its name from the Dutch word for seals (''robben''), hence the Dutch/Afrik ...

. The adults fly to the mainland to find food for their chicks, a round trip of about 24 km.

Feeding

The species is omnivorous like most ''Larus'' gulls, and they will scavenge at tips and feed on scraps as well as seeking suitable small prey, often by wading in shallow water.

References

* Harrison, ''Seabirds'' * Ian Sinclair, Phil Hockey and Warwick Tarboton, ''SASOL Birds of Southern Africa'' (Struik 2002) * Pons J.M., Hassanin, A., and Crochet P.A.(2005). ''Phylogenetic relationships within the Laridae (Charadriiformes: Aves) inferred from mitochondrial markers.'' Molecular Phylogenetics and Evolution 37(3):686–699

External links

Species text in The Atlas of Southern African Birds
{{Taxonbar, from=Q1274356

Hartlaub's gull Hartlaub's gull (''Chroicocephalus hartlaubii''), also known as the king gull, it is a small gull. It was formerly sometimes considered to be a subspecies of the silver gull (''C. novaehollandiae''), and, as is the case with many gulls, it has t ...

Birds of Southern Africa