Hartlaub's Gull
Encyclopedia
The Hartlaub's Gull or King Gull, (Chroicocephalus hartlaubii) is a small gull
, which is a non-migratory
breeding resident endemic to the Atlantic Ocean
coastline of South Africa
and Namibia
. Although it is predominantly coastal or estuarine, it is not a pelagic species, and is rarely seen at sea far from land. 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 traditionally been placed in the genus
Larus
but is now placed in the genus Chroicocephalus
.
About one half of the total population, currently estimated at about 30 000 birds, are within the Greater Cape Town
area. It breeds in large colonies, and the main traditional breeding colony for the Cape Town area is on Robben Island
. The adults fly to the mainland to find food for their chicks, a round trip of about 24 km.
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
in its thinner, darker bill, deeper red legs, paler, plainer head, and dark eyes.
The Hartlaub's Gull 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.
Hartlaub's Gull has accommodated well to humans, and can become very tame around habitations. It is an omnivore 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.
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.
Like most gulls, it 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
-like kaaarrh. This species is frequently the subject of complaints about the noise it makes in urban areas.
This species’ name commemorates the German physician and zoologist, Gustav Hartlaub
.
Gull
Gulls are birds in the family Laridae. They are most closely related to the terns and only distantly related to auks, skimmers, and more distantly to the waders...
, which is a non-migratory
Bird migration
Bird migration is the regular seasonal journey undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat or weather. Sometimes, journeys are not termed "true migration" because they are irregular or in only one direction...
breeding resident endemic to the Atlantic Ocean
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
coastline of South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
and Namibia
Namibia
Namibia, officially the Republic of Namibia , is a country in southern Africa whose western border is the Atlantic Ocean. It shares land borders with Angola and Zambia to the north, Botswana to the east and South Africa to the south and east. It gained independence from South Africa on 21 March...
. Although it is predominantly coastal or estuarine, it is not a pelagic species, and is rarely seen at sea far from land. It was formerly sometimes considered to be a subspecies of the Silver Gull
Silver Gull
The Silver Gull also known simply as "seagull" in Australia, is the most common gull seen in Australia. It has been found throughout the continent, but particularly coastal areas. The South African Hartlaub's Gull and the New Zealand Red-billed Gull The Silver Gull (Chroicocephalus...
(C. novaehollandiae), and, as is the case with many gulls, it has traditionally been placed in the genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Larus
Larus
Larus is a large genus of gulls with worldwide distribution . Many of its species are abundant and well-known birds in their ranges...
but is now placed in the genus Chroicocephalus
Chroicocephalus
Chroicocephalus is a genus of medium to relatively small gulls which were once included in the genus Larus. Some authorities also include the Saunders's Gull in Chroicocephalus...
.
About one half of the total population, currently estimated at about 30 000 birds, are within the Greater Cape Town
Cape Town
Cape Town is the second-most populous city in South Africa, and the provincial capital and primate city of the Western Cape. As the seat of the National Parliament, it is also the legislative capital of the country. It forms part of the City of Cape Town metropolitan municipality...
area. It breeds in large colonies, and the main traditional breeding colony for the Cape Town area is on Robben Island
Robben Island
Robben Island is an island in Table Bay, 6.9 km west of the coast of Bloubergstrand, Cape Town, South Africa. The name is Dutch for "seal island". Robben Island is roughly oval in shape, 3.3 km long north-south, and 1.9 km wide, with an area of 5.07 km². It is flat and only a...
. The adults fly to the mainland to find food for their chicks, a round trip of about 24 km.
Grey-headed Gull
The Grey-headed Gull is a small gull which breeds patchily in South America and Africa south of the Sahara. It is not truly migratory, but is more widespread in winter. This species has occurred as a rare vagrant to North America and Spain. It is also known as the Grey-hooded Gull...
in its thinner, darker bill, deeper red legs, paler, plainer head, and dark eyes.
The Hartlaub's Gull 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.
Hartlaub's Gull has accommodated well to humans, and can become very tame around habitations. It is an omnivore 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.
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.
Like most gulls, it 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
Crow
Crows form the genus Corvus in the family Corvidae. Ranging in size from the relatively small pigeon-size jackdaws to the Common Raven of the Holarctic region and Thick-billed Raven of the highlands of Ethiopia, the 40 or so members of this genus occur on all temperate continents and several...
-like kaaarrh. This species is frequently the subject of complaints about the noise it makes in urban areas.
This species’ name commemorates the German physician and zoologist, Gustav Hartlaub
Gustav Hartlaub
Karel Johan Gustav Hartlaub 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 collect exotic birds, which he donated to the Bremen Natural History Museum. He described some...
.
External links
- Hartlaub's Gull, Avian Demography Unit, University of Cape Town