White-headed Black-chat
Encyclopedia
Arnot's Chat, also called the White-headed Black-chat, (Myrmecocichla arnotti) is a species of bird
in the chat and flycatcher family Muscicapidae.
The species is found in southern Africa from Tanzania
and Angola
to South Africa
.
in 1869 based upon a specimen collected at Victoria Falls
in modern-day Zimbabwe
, as Saxicola arnotti. Tristram wrote that he named the species after the collector, a Mr. Arnott, but the man was actually named David Arnot. For this reason, it was suggested in 1965 that the name should be spelled arnoti instead. However, since there is no evidence in Tristram's original paper that the name was misspelled, the rules of the International Code of Zoological Nomenclature
mandate that the spelling arnotti be maintained.
Along with the White-fronted Black-chat
this species is sometimes separated into the genus Pentholaea. The species contains two subspecies, hartertii, which is found in Angola, and the nominate, which is found across the rest of its range. A third subspecies, collariis, has recently been split off as a separate species, the Ruaha Chat. This species is indistinguishable from Arnot's Chat in male birds but has different plumage
in females, a difference that has mostly been overlooked for over a century.
and mopane
woodland. It also occurs at lower densities in other kinds of open woodland with little herbaceous cover, and very rarely near buildings. It generally occurs from sea level to 1500 m (4,921.3 ft) , but has been recorded up to 1840 m (6,036.7 ft) in the Democratic Republic of the Congo
.The species is generally not migratory
, but is presumed to undertake some localized wandering.
of the adults is sexually dimorphic
; the male of the nominate race is overall black with a white crown and a white patch on the wing coverts
. The female is similar but with a black crown and a white (tipped with black) throat and neck. The bill and legs are black. Juvenile birds are like the adults but with white feather tips on the crown or throat instead of fuller white. The male of the race harterti has less extensive white on the wings and a mostly black head with a small area of white on the forehead and above the eye; the white throat of the female is also less extensive than on the nominate.
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
in the chat and flycatcher family Muscicapidae.
The species is found in southern Africa from Tanzania
Tanzania
The United Republic of Tanzania is a country in East Africa bordered by Kenya and Uganda to the north, Rwanda, Burundi, and the Democratic Republic of the Congo to the west, and Zambia, Malawi, and Mozambique to the south. The country's eastern borders lie on the Indian Ocean.Tanzania is a state...
and Angola
Angola
Angola, officially the Republic of Angola , is a country in south-central Africa bordered by Namibia on the south, the Democratic Republic of the Congo on the north, and Zambia on the east; its west coast is on the Atlantic Ocean with Luanda as its capital city...
to 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...
.
Taxonomy
The species was described by Henry Baker TristramHenry Baker Tristram
The Reverend Henry Baker Tristram FRS was an English clergyman, Biblical scholar, traveller and ornithologist.Tristram was born at Eglingham vicarage, near Alnwick, Northumberland, and studied at Durham School and Lincoln College, Oxford. In 1846 he was ordained a priest, but he suffered from...
in 1869 based upon a specimen collected at Victoria Falls
Victoria Falls
The Victoria Falls or Mosi-oa-Tunya is a waterfall located in southern Africa on the Zambezi River between the countries of Zambia and Zimbabwe.-Introduction:...
in modern-day Zimbabwe
Zimbabwe
Zimbabwe is a landlocked country located in the southern part of the African continent, between the Zambezi and Limpopo rivers. It is bordered by South Africa to the south, Botswana to the southwest, Zambia and a tip of Namibia to the northwest and Mozambique to the east. Zimbabwe has three...
, as Saxicola arnotti. Tristram wrote that he named the species after the collector, a Mr. Arnott, but the man was actually named David Arnot. For this reason, it was suggested in 1965 that the name should be spelled arnoti instead. However, since there is no evidence in Tristram's original paper that the name was misspelled, the rules of the International Code of Zoological Nomenclature
International Code of Zoological Nomenclature
The International Code of Zoological Nomenclature is a widely accepted convention in zoology that rules the formal scientific naming of organisms treated as animals...
mandate that the spelling arnotti be maintained.
Along with the White-fronted Black-chat
White-fronted Black-chat
The White-fronted Black Chat is a species of bird in the Muscicapidae family.It is found in Benin, Burkina Faso, Cameroon, Central African Republic, Chad, Democratic Republic of the Congo, Ivory Coast, Eritrea, Ethiopia, Gambia, Ghana, Guinea, Guinea-Bissau, Mali, Mauritania, Niger, Nigeria,...
this species is sometimes separated into the genus Pentholaea. The species contains two subspecies, hartertii, which is found in Angola, and the nominate, which is found across the rest of its range. A third subspecies, collariis, has recently been split off as a separate species, the Ruaha Chat. This species is indistinguishable from Arnot's Chat in male birds but has different plumage
Plumage
Plumage refers both to the layer of feathers that cover a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage vary between species and subspecies and can also vary between different age classes, sexes, and season. Within species there can also be a...
in females, a difference that has mostly been overlooked for over a century.
Habitat
The Arnot's Chat is most commonly found in healthy stands of miomboMiombo
Miombo is the Swahili word for Brachystegia, a genus of tree comprising a large number of species. Miombo woodland is classified in the tropical and subtropical grasslands, savannas, and shrublands biome...
and mopane
Mopane
The mopane or mopani tree grows in hot, dry, low-lying areas, in elevation, in the far northern parts of southern Africa, into South Africa, Zimbabwe, Mozambique, Botswana, Zambia, Namibia, Angola and Malawi. The tree only occurs in Africa and is the only species in genus Colophospermum...
woodland. It also occurs at lower densities in other kinds of open woodland with little herbaceous cover, and very rarely near buildings. It generally occurs from sea level to 1500 m (4,921.3 ft) , but has been recorded up to 1840 m (6,036.7 ft) in the Democratic Republic of the Congo
Democratic Republic of the Congo
The Democratic Republic of the Congo is a state located in Central Africa. It is the second largest country in Africa by area and the eleventh largest in the world...
.The species is generally not 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...
, but is presumed to undertake some localized wandering.
Description
The Arnot's Chat ranges in size from 16 to 18 cm (6.3 to 7.1 in) and weighs around 35 g (1.2 oz). The plumagePlumage
Plumage refers both to the layer of feathers that cover a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage vary between species and subspecies and can also vary between different age classes, sexes, and season. Within species there can also be a...
of the adults is sexually dimorphic
Sexual dimorphism
Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...
; the male of the nominate race is overall black with a white crown and a white patch on the wing coverts
Flight feather
Flight feathers are the long, stiff, asymmetrically shaped, but symmetrically paired feathers on the wings or tail of a bird; those on the wings are called remiges while those on the tail are called rectrices . Their primary function is to aid in the generation of both thrust and lift, thereby...
. The female is similar but with a black crown and a white (tipped with black) throat and neck. The bill and legs are black. Juvenile birds are like the adults but with white feather tips on the crown or throat instead of fuller white. The male of the race harterti has less extensive white on the wings and a mostly black head with a small area of white on the forehead and above the eye; the white throat of the female is also less extensive than on the nominate.