| Blue-throated roller | |
|---|---|
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Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Order: | Coraciiformes |
| Family: | Coraciidae |
| Genus: | Eurystomus |
| Species: | E. gularis |
| Binomial name | |
| Eurystomus gularis Vieillot, 1819 | |
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resident range | |
The blue-throated roller (Eurystomus gularis) is a species of roller in the family Coraciidae. It is native to the African tropical rainforest.
The blue-throated roller was formally described in 1819 by the French ornithologist Louis Pierre Vieillot under its current binomial name Eurystomus gularis. [2] The specific epithet gularis is Modern Latin meaning "-throated". [3] Vieillot based his description on a specimen in the Muséum National d'Histoire Naturelle in Paris which he mistaken believed had been collected in "Australasie"; the type locality has been designated as Senegal. [4] A molecular phylogenetic study published in 2018 found that the blue-throated roller was most closely related to the broad-billed roller (Eurystomus glaucurus). [5]
Two subspecies are recognized: [6]
The blue-throated roller is a dumpy, large-headed, thick-necked bird that frequents the tops of trees. Overall, it is a dark bird, mainly chestnut brown with a bright yellow bill and a blue patch on the throat, a blue tail and purplish blue wings. The juvenile shows bluish on the underparts. It is a rather long-winged roller and can give a falcon like silhouette in flight. [7] It measures 25 cm in length; the males weigh 82–117.5 g, the females 88–108g. [8]
The blue-throated roller occurs in western sub-Saharan Africa from Guinea to Cameroon, south to northern Angola, and west to south-eastern Uganda. [7] It is also found on Bioko Island. [9]
The blue-throated roller tends to remain high up in the tops of trees and hunts above the canopy of primary and secondary rainforest, plantations, gallery forests and relict forest patches in cleared regions. They prefer clearings, riversides and giant emergent trees. [7]
The blue-throated roller perches high up, either singly or in pairs, on bare branches, frequently at the very top of the canopy. They often sit for long periods, and sometimes make their shrill chattering calls. When active they hawk insects in the air and aggressively defend their territory from other bird species. In the late afternoon the birds gather in small flocks, often mixed with broad-billed rollers, to feed on ants and termites which emerge after a rainfall. The rollers feed on these insects in flight, acrobatically chasing them and eating them on the wing. This activity continues until dusk and one roller may eat over 700 insects weighing 40g. [7]
The blue-throated roller is a territorial species when breeding and both courtship and territorial defence involve noisy aerial chases. The nest is an unlined cavity, normally about 10m up the trunk of a tree on the edge of a clearing; 2-3 eggs are laid with laying recorded in February to March in the Ivory Coast, February to April in Ghana, April and September in Nigeria, January in Gabon, and April and October in the Democratic Republic of Congo. [7]
Coraciidae is a family of Old World birds, which are known as rollers because of the aerial acrobatics some of these birds perform during courtship or territorial flights. Rollers resemble crows in size and build, and share the colourful appearance of kingfishers and bee-eaters, blues and pinkish or cinnamon browns predominating. The two inner front toes are connected, but not the outer one.
Eurystomus is a genus of roller, one of the two genera in that family of birds. The name means ‘broad mouth’, from the Greek eurus and stoma.
Coracias is a genus of the rollers, an Old World family of near passerine birds related to the kingfishers and bee-eaters. They share the colourful appearance of those groups, blues and browns predominating. The two outer front toes are connected, but not the inner one.
The black-capped kingfisher is a tree kingfisher which is widely distributed in tropical Asia from India east to China, Korea and Southeast Asia. This most northerly of the tree kingfishers is resident over much of its range, but northern populations are migratory, wintering south of their range in Sri Lanka, Thailand, Borneo and Java. It is distinctive in having a black cap that contrasts with the whitish throat, purple-blue wings and the coral red bill. The species is mainly found in coastal and mangrove habitats but can sometimes be found far inland.
The trilling gnatwren, formerly long-billed gnatwren, is a very small bird in the gnatcatcher family. It found from southeast Mexico south to Ecuador and Amazonia.
The Oriental dollarbird is a bird of the roller family, so named because of the distinctive pale blue or white, coin-shaped spots on its wings. It can be found from Australia to Korea, Japan and India.
The African pygmy kingfisher is a small insectivorous kingfisher found in the Afrotropics, mostly in woodland habitats.
Synallaxis is a genus of birds in the ovenbird family, Furnariidae. It is one of the most diverse genera in the family and is composed of small birds that inhabit dense undergrowth across tropical and subtropical habitats in the Neotropical region. Some species show contrasting plumage patterns involving rufous crown and wing patches and black throat patches but they are difficult to see as they keep ensconced in vegetation most of the time. Most species show the long graduated tail with pointy feathers that is typical of spinetails. They are also characterized by constructing large domed nests with stick, including a long entrance tube. Some species can be difficult to distinguish from one another on the basis of their plumage, but can be told apart by their vocalizations, which can be quite distinctive.
The cardinal woodpecker is a widespread and common resident breeder in much of sub-Saharan Africa. It occurs in a wide range of habitats, ranging from dense forest to thorn bush. It is fairly vocal and is easily identified by its call notes. The sexes are distinguishable by their head patterns.
The cerulean kingfisher is a kingfisher in the subfamily Alcedininae which is native to parts of Indonesia. With an overall metallic blue impression, it is very similar to the common kingfisher, but it is white underneath instead of orange. Males average bluer than females, which have a greenish cast.
The chestnut-vented warbler, chestnut-vented tit-babbler or rufous-vented warbler is an Old World warbler.
The swallow tanager is a species of Neotropic bird in the tanager family Thraupidae. It is the only member of the genus Tersina. It is found widely throughout South America, from eastern Panama to far northern Argentina. The species is sexually dimorphic: the female is a yellow-green and the male a turquoise blue with a small deep black face and upper throat patch.
The purple roller, or rufous-crowned roller, is a medium-sized bird widespread in sub-Saharan Africa. Compared with other rollers its colours are rather dull and its voice harsh and grating.
The red-throated caracara is a social species of bird of prey in the family Falconidae. It is placed in the monotypic genus Ibycter, or sometimes united in Daptrius with the black caracara. Unique among caracaras, it mainly feeds on the larvae of bees and wasps, but also takes the adult insects and fruits and berries.
The racket-tailed roller is a species of bird in the family Coraciidae. It is found in southern Africa from Angola, south-eastern Democratic Republic of Congo and southern Tanzania to northern Botswana, Zimbabwe, Malawi and Mozambique.
The purple-winged roller is a species of bird in the family Coraciidae. It is endemic to the Sulawesi subregion in Indonesia and can be found on the islands of Sulawesi, Bangka, Lembeh, Manterawu, Muna and Butung.
The chattering kingfisher is a species of bird in the kingfisher family Alcedinidae. The species is found in the Cook Islands and the Society Islands in French Polynesia.
The blue-backed tanager is a species of South American bird in the tanager family Thraupidae. It is the only member of the genus Cyanicterus.
The African pitta is an Afrotropical bird of the family Pittidae. It is a locally common to uncommon species, resident and migratory in the west, and an intra-African migrant between equatorial and southeastern Africa. They are elusive and hard to observe despite their brightly coloured plumage, and their loud, explosive calls are infrequently heard. The plump, somewhat thrush-like birds forage on leaf litter under the canopy of riparian or coastal forest and thickets, or in climax miombo forest. They spend much time during mornings and at dusk scratching in leaf litter or around termitaria, or may stand motionless for long periods. Following rains breeding birds call and display from the mid-canopy.
The broad-billed roller is a member of the roller family of birds which breeds across tropical Africa and Madagascar in all but the driest regions. It is a wet season breeder, which migrates from the northern and southern areas of its range towards the moister equatorial belt in the dry season.
