Thamnophilidae
211 species
The antbirds are a large passerine bird family, Thamnophilidae, found across subtropical and tropical Central and South America, from Mexico to Argentina. There are more than 230 species, known variously as antshrikes, antwrens, antvireos, fire-eyes, bare-eyes and bushbirds. They are related to the antthrushes and antpittas (family Formicariidae), the tapaculos, the gnateaters and the ovenbirds. Despite some species' common names, this family is not closely related to the wrens, vireos or shrikes.
Antbirds are generally small birds with rounded wings and strong legs. They have mostly sombre grey, white, brown and rufous plumage, which is sexually dimorphic in pattern and colouring. Some species communicate warnings to rivals by exposing white feather patches on their backs or shoulders. Most have heavy bills, which in many species are hooked at the tip.
Most species live in forests, although a few are found in other habitats. Insects and other arthropods form the most important part of their diet, although small vertebrates are occasionally taken. Most species feed in the understory and midstory of the forest, although a few feed in the canopy and a few on the ground. Many join mixed-species feeding flocks, and a few species are core members. To various degrees, around eighteen species specialise in following swarms of army ants to eat the small invertebrates flushed by the ants, and many others may feed in this way opportunistically.
Antbirds are monogamous, mate for life, and defend territories. They usually lay two eggs in a nest that is either suspended from branches or supported on a branch, stump, or mound on the ground. Both parents share the tasks of incubation and of brooding and feeding the nestlings. After fledging, each parent cares exclusively for one chick.
Thirty-eight species are threatened with extinction as a result of human activities. Antbirds are not targeted by either hunters or the pet trade. The principal threat is habitat loss, which causes habitat fragmentation and increased nest predation in habitat fragments.
The distribution of the antbirds is entirely Neotropical, with the vast majority of the species being found in the tropics. A few species reach southern Mexico and northern Argentina. Some species, such as the barred antshrike, have a continental distribution that spans most of the South and Middle American distribution of the family; others, such as the ash-throated antwren, have a tiny distribution.
Antbirds are mostly birds of humid lowland rainforests. Few species are found at higher elevations, with less than 10% of species having ranges above 2000 m (6500 ft) and almost none with ranges above 3000 m (10000 ft). The highest species diversity is found in the Amazon basin, with up to 45 species being found in single locations in sites across Brazil, Colombia, Bolivia and Peru. The number of species drops dramatically towards the further reaches of the family's range; there are only seven species in Mexico, for example. Areas of lower thamnophilid diversity may contain localised endemics, however. The Yapacana antbird, for example, is restricted to the stunted woodlands that grow in areas of nutrient-poor white-sand soil (the so-called Amazonian caatinga) in Brazil, Venezuela and Colombia. Some species are predominantly associated with microhabitats within a greater ecosystem; for example, the bamboo antshrike is predominantly found in bamboo patches.
Genetic comparison of the whole genomes of higher and lower-humidity antbirds have shown some differences in genes linked to water balance and temperature regulation. More significantly, antbirds differ in the regions of the genome that regulate gene activity, suggesting that differences for antbirds are a result less of the genes themselves than of how they are deployed.
The antbirds are a large passerine bird family, Thamnophilidae, found across subtropical and tropical Central and South America, from Mexico to Argentina. There are more than 230 species, known variously as antshrikes, antwrens, antvireos, fire-eyes, bare-eyes and bushbirds. They are related to the antthrushes and antpittas (family Formicariidae), the tapaculos, the gnateaters and the ovenbirds. Despite some species' common names, this family is not closely related to the wrens, vireos or shrikes.
Antbirds are generally small birds with rounded wings and strong legs. They have mostly sombre grey, white, brown and rufous plumage, which is sexually dimorphic in pattern and colouring. Some species communicate warnings to rivals by exposing white feather patches on their backs or shoulders. Most have heavy bills, which in many species are hooked at the tip.
Most species live in forests, although a few are found in other habitats. Insects and other arthropods form the most important part of their diet, although small vertebrates are occasionally taken. Most species feed in the understory and midstory of the forest, although a few feed in the canopy and a few on the ground. Many join mixed-species feeding flocks, and a few species are core members. To various degrees, around eighteen species specialise in following swarms of army ants to eat the small invertebrates flushed by the ants, and many others may feed in this way opportunistically.
Antbirds are monogamous, mate for life, and defend territories. They usually lay two eggs in a nest that is either suspended from branches or supported on a branch, stump, or mound on the ground. Both parents share the tasks of incubation and of brooding and feeding the nestlings. After fledging, each parent cares exclusively for one chick.
Thirty-eight species are threatened with extinction as a result of human activities. Antbirds are not targeted by either hunters or the pet trade. The principal threat is habitat loss, which causes habitat fragmentation and increased nest predation in habitat fragments.
The distribution of the antbirds is entirely Neotropical, with the vast majority of the species being found in the tropics. A few species reach southern Mexico and northern Argentina. Some species, such as the barred antshrike, have a continental distribution that spans most of the South and Middle American distribution of the family; others, such as the ash-throated antwren, have a tiny distribution.
Antbirds are mostly birds of humid lowland rainforests. Few species are found at higher elevations, with less than 10% of species having ranges above 2000 m (6500 ft) and almost none with ranges above 3000 m (10000 ft). The highest species diversity is found in the Amazon basin, with up to 45 species being found in single locations in sites across Brazil, Colombia, Bolivia and Peru. The number of species drops dramatically towards the further reaches of the family's range; there are only seven species in Mexico, for example. Areas of lower thamnophilid diversity may contain localised endemics, however. The Yapacana antbird, for example, is restricted to the stunted woodlands that grow in areas of nutrient-poor white-sand soil (the so-called Amazonian caatinga) in Brazil, Venezuela and Colombia. Some species are predominantly associated with microhabitats within a greater ecosystem; for example, the bamboo antshrike is predominantly found in bamboo patches.
Genetic comparison of the whole genomes of higher and lower-humidity antbirds have shown some differences in genes linked to water balance and temperature regulation. More significantly, antbirds differ in the regions of the genome that regulate gene activity, suggesting that differences for antbirds are a result less of the genes themselves than of how they are deployed.
