Oxpeckers | |
---|---|
Yellow-billed oxpeckers Buphagus africanus africanus on a zebra in Senegal | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Aves |
Order: | Passeriformes |
Superfamily: | Muscicapoidea |
Family: | Buphagidae Lesson, 1828 |
Genus: | Buphagus Brisson, 1760 |
Type species | |
Buphaga africana [1] Linnaeus, 1766 | |
Species | |
The oxpeckers are two species of bird which make up the genus Buphagus, and family Buphagidae. The oxpeckers were formerly usually treated as a subfamily, Buphaginae, within the starling family, Sturnidae, but molecular phylogenetic studies have consistently shown that they form a separate lineage that is basal to the sister clades containing the Sturnidae and the Mimidae (mockingbirds, thrashers, and allies). Oxpeckers are endemic to the savanna of Sub-Saharan Africa.
Both the English and scientific names arise from their habit of perching on large mammals (both wild and domesticated) such as cattle, zebras, impalas, hippopotamuses, rhinoceroses, and giraffes, eating ticks, small insects, botfly larvae, and other parasites, as well as the animals' blood. The behaviour of oxpeckers towards large mammals was thought to be exclusively mutual, though recent research suggests the relationship can be parasitic in nature as well. [2]
The Swahili name for the red-billed oxpecker is Askari wa kifaru (the rhino's guard). [3]
The genus Buphagus was introduced in 1760 by the French zoologist Mathurin Jacques Brisson with the yellow-billed oxpecker as the type species. [4] The name combines the Ancient Greek words bous "ox" and -phagos "eating". [5]
According to the more recent studies of Muscicapoidea phylogeny, the oxpeckers are an ancient line related to Mimidae (mockingbirds and thrashers) and starlings but not particularly close to either. [6] [7] [8] Considering the known biogeography of these groups, the most plausible explanation seems that the oxpecker lineage originated in Eastern or Southeastern Asia like the other two. [7] This would make the two species of Buphagus something like living fossils, and demonstrates that such remnants of past evolution can possess striking and unique autapomorphic adaptations.
The genus contains two species: [9]
Common name | Scientific name and subspecies | Range | Size and ecology | IUCN status and estimated population |
---|---|---|---|---|
Yellow-billed oxpecker | Buphagus africanus Linnaeus, 1766 Two subspecies
| most of sub-Saharan Africa | Size: Habitat: Diet: | LC |
Red-billed oxpecker | Buphagus erythrorynchus (Stanley, 1814) | mainly east Africa | Size: Habitat: Diet: | LC |
The oxpeckers are endemic to sub-Saharan Africa, where they occur in most open habitats. They are absent from the driest deserts and the rainforests. Their distribution is restricted by the presence of their preferred prey, specific species of ticks, and the animal hosts of those ticks. The two species of oxpecker are sympatric over much of East Africa and may even occur on the same host animal. The nature of the interactions between the two species is unknown.
Oxpeckers graze exclusively on the bodies of large mammals. Certain species are seemingly preferred, whereas others, like the Lichtenstein's hartebeest or topi are generally avoided. Smaller antelope such as lechwe, duikers and reedbuck are also avoided; the smallest regularly used species is the impala, probably because of the heavy tick load and social nature of that species. In many parts of their range they now feed on cattle, but avoid camels. They feed on ectoparasites, particularly ticks, as well as insects infesting wounds and the flesh and blood of some wounds as well. They are sometimes classified as parasites, because they open wounds on the animals' backs. [10]
Oxpecker/mammal interactions are the subject of some debate and ongoing research. [11] They were originally thought to be an example of mutualism, but recent evidence suggests that oxpeckers may be parasites instead. [12] Oxpeckers do eat ticks, but often the ticks have already fed on the ungulate host, and no statistically significant link has been shown between oxpecker presence and reduced ectoparasite load. [12] Oxpeckers have been observed to open new wounds and enhance existing ones in order to drink the blood of their perches. [13] Oxpeckers also feed on the earwax and dandruff of mammals; less is known about the possible benefits of this to the mammal, but it is suspected that this is also a parasitic behaviour. [12] Some oxpeckers' hosts are intolerant of their presence. [13] Elephants and some antelope will actively dislodge the oxpeckers when they land. However there have been noted instances of elephants allowing oxpeckers to eat parasites off of them. [14] Other species tolerate oxpeckers while they search for ticks on their faces, which one author says "appears ... to be an uncomfortable and invasive process." [10]
The breeding season of the oxpeckers, in at least one location, is linked to the rainy season, which affects the activity of their mammalian hosts and the tick loads of those hosts. Both courtship and copulation occur on their hosts as well. They nest in holes, usually in trees but sometimes in other types of cavity, including holes in walls. The nests are lined with grasses and often with hair plucked from their hosts and even livestock such as sheep which are not usually used. The typical clutch is between two and three eggs, but the red-billed oxpecker may lay up to five eggs.
Red-billed oxpeckers have been known to roost in reeds and trees. Studies of large savanna herbivores using cameras at night have shown that both species of oxpecker (but more often in yellow-billed oxpecker) may also roost on the bodies of herbivores, hanging under the insides of the thighs of giraffe and on top of impala and buffalo. [15]
The Philippine creepers or rhabdornises are small passerine birds and form the genus Rhabdornis. They are endemic to the Philippines. They do not migrate, other than to make local movements.
The mimids are the New World family of passerine birds, Mimidae, that includes thrashers, mockingbirds, tremblers, and the New World catbirds. As their name suggests, these birds are notable for their vocalization, especially some species' remarkable ability to mimic a wide variety of birds and other sounds heard outdoors. They are commonly referred to as mimic thrushes but are not, in fact, thrushes.
Starlings are small to medium-sized passerine birds in the family Sturnidae, common name of Sturnid. The Sturnidae are named for the genus Sturnus, which in turn comes from the Latin word for starling, sturnus. The family contains 128 species which are divided into 36 genera. Many Asian species, particularly the larger ones, are called mynas, and many African species are known as glossy starlings because of their iridescent plumage. Starlings are native to Europe, Asia, and Africa, as well as northern Australia and the islands of the tropical Pacific. Several European and Asian species have been introduced to these areas, as well as North America, Hawaii, and New Zealand, where they generally compete for habitats with native birds and are considered to be invasive species. The starling species familiar to most people in Europe and North America is the common starling, and throughout much of Asia and the Pacific, the common myna is indeed common.
The impala or rooibok is a medium-sized antelope found in eastern and southern Africa. The only extant member of the genus Aepyceros, and tribe Aepycerotini, it was first described to Europeans by German zoologist Hinrich Lichtenstein in 1812. Two subspecies are recognised—the grassland-dwelling common impala, and the larger and darker black-faced impala, which lives in slightly more arid, scrubland environments. The impala reaches 70–92 cm (28–36 in) at the shoulder and weighs 40–76 kg (88–168 lb). It features a glossy, reddish brown coat. The male's slender, lyre-shaped horns are 45–92 cm (18–36 in) long.
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The yellow-billed oxpecker is a passerine bird in the family Buphagidae. It was previously placed in the starling and myna family, Sturnidae.
The red-billed oxpecker is a passerine bird in the oxpecker family, Buphagidae. It is native to the eastern savannah of sub-Saharan Africa, from the Central African Republic east to South Sudan and south to northern and eastern South Africa. It is more widespread than the yellow-billed oxpecker in Southern Africa, where their ranges overlap.
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Lamprotornis is a large genus of glossy-starlings all of which occur in Africa south of the Sahara. They have glossy blue or green upper parts, which is due to hollow melanin granules arranged in a single layer near the feather barbule's surface. This unique arrangement led to some glossy starlings formerly placed in the genus Spreo being transferred to Lamprotornis, since they shared this feature.
The white-cheeked starling or grey starling is a passerine bird of the starling family. It is native to eastern Asia where it is a common and well-known bird in much of its range.
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The chestnut-cheeked starling is a species of starling in the family Sturnidae. It breeds in Japan and the Russian islands of Sakhalin and Kuriles; it winters in Taiwan, the Philippines and northern Borneo.
The red-billed starling is a species of starling in the family Sturnidae. It is found in south and southeastern China.
The white-shouldered starling is a species of bird in the starling family Sturnidae. It breeds in southern China and northern Vietnam; it winters in Southeast Asia.
The Daurian starling, or purple-backed starling, is a species of bird in the starling family found in the eastern Palearctic from eastern Mongolia and southeastern Russia to North Korea and central China.
Agropsar is a genus of Asian birds in the family Sturnidae. It is sometimes merged with Sturnus or Sturnia
Muscicapida is a clade of birds in the order Passeriformes. Oliveros, C.H. et al. (2019) suggested a gondwanan migration of this lineage from Australia to Eurasia.