Ant follower

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The bicoloured antbird is an obligate ant-follower. Gymnopithys-leucaspis-001 edit2.jpg
The bicoloured antbird is an obligate ant-follower.

Ant followers are birds that feed by following swarms of army ants and take prey flushed by those ants. [1] The best-known ant-followers are 18 species of antbird in the family Thamnophilidae, but other families of birds may follow ants, including thrushes, chats, ant-tanagers, cuckoos, motmots, and woodcreepers.

Ant followers may be obligate, meaning that they derive most of their diet by following ant swarms, or non-obligate, meaning they derive only some of their diet from this behaviour. Some species may feed extensively at ant swarms yet may not be obligate ant followers, being able to and regularly feeding away from the swarms as well.

Many species of tropical ants form large raiding swarms, but the swarms are often nocturnal or raid underground. While birds visit these swarms when they occur, the species most commonly attended by birds is the Neotropical species Eciton burchellii , [1] which is both diurnal and surface-raiding.

It was once thought that attending birds were actually eating the ants, but numerous studies in various parts of E. burchellii's range has shown that the ants act as beaters, flushing insects, other arthropods and small vertebrates into the waiting flocks of "ant followers". Because E. burchellii is the only regular diurnal army ant specialised and regular ant-followers mostly occur in its Neotropical range, but Afrotropical birds do follow driver ants in the genus Dorylus . [2]

It was once suggested that the relationship between the obligate and regular ant-followers and the army ants, particularly Eciton burchellii, was mutualistic, with the ants benefiting by having the birds chase prey back down towards them. However experiments where ant followers were excluded have shown that the foraging success of the army ants was 30% lower when the birds were present, suggesting that the birds' relationship was in fact parasitic. [3] This has resulted in a number of behaviours by the ants in order to reduce kleptoparasitism, including hiding of secured prey in the leaf litter and caching of food on trails. It has been suggested that the depressive effect of this parasitism slows the development of E. burchellii swarms and in turn benefits other ant species which are preyed upon by army ants.

Despite the easier availability of prey, ant followers face an element of risk, as these small birds can be killed by as little as four stings from fire ants. [4]

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<span class="mw-page-title-main">Bivouac (ants)</span>

A bivouac is an organic structure formed by migratory driver ant and army ant colonies, such as the species Eciton burchellii. A nest is constructed out of the living ant workers' own bodies to protect the queen and larvae, and is later deconstructed as the ants move on.

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<i>Eciton burchellii</i> Species of ant

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<i>Eciton hamatum</i> Species of ant

Eciton hamatum is a species of army ant in the subfamily Dorylinae; it is found from Mexico to central Brazil and Bolivia. The species differs from Eciton burchellii, in that it does not fan out into the underbrush when foraging. Rather, it forages in columns, often in trees and preying exclusively on the larvae of other social insects. Its prey are often broods of vespid wasps and ants of genera Dolichoderus and Camponotus, suggesting that E. hamatum is mainly an arboreal forager.

<i>Eciton</i> Genus of ants

Eciton is a New World army ant genus that contains the most familiar species of army ants. The most predominant and well-known species is Eciton burchellii, which is also more commonly known as the army ant and is considered the type species.

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<span class="mw-page-title-main">Blue-lored antbird</span> Species of bird

The blue-lored antbird is a species of antbird in the family Thamnophilidae. It is found at low levels in humid Andean forests in western and northern Colombia, western Venezuela. It formerly included the Zeledon's antbird as a subspecies. The blue-lored antbird feeds on insects, and regularly follows swarms of army ants in order to catch prey flushed by the swarms, but it is not an obligate ant-follower like some species of antbirds. The blue-lored antbird is strongly sexually dichromatic: the male has an entirely black plumage, while the female has a rufous-brown plumage and a black mask. Both sexes have a blue patch of skin around the eyes.

<span class="mw-page-title-main">Black-faced antbird</span> Species of bird

The black-faced antbird is a species of bird, about 12–13 cm (5 inches) long, in the antbird family Thamnophilidae. It is endemic to a wide range across the Amazon basin. It feeds on insects and spiders and sometimes follows army ants to catch the insects disturbed by their march.

<span class="mw-page-title-main">Ocellated antbird</span> Species of bird

The ocellated antbird is a species of antbird in the family Thamnophilidae. It is monotypic within the genus Phaenostictus and is found in southern Central America and the northwestern part of South America. Its natural habitat is the understory of tropical moist lowland forest, foothill forest, and tall secondary growth woodlands.

<span class="mw-page-title-main">White-plumed antbird</span> Species of bird

The white-plumed antbird is a small species of insectivorous bird found in the understories of rainforests. It is smaller than most species of its family (Thamnophilidae), weighing 26 grams on average. The family Thamnophilidae is known commonly as the antbirds, as they use the presence of ants to locate food. This species is largely solitary except during the breeding season, and different individuals will follow individual ant swarms.

<span class="mw-page-title-main">Myrmecophagy</span> Feeding on termites or ants

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<span class="mw-page-title-main">Zeledon's antbird</span> Species of bird

Zeledon's antbird is a species of antbird in the family Thamnophilidae. It is found at low levels in humid forests from Nicaragua to Panama, and in the Chocó of western Colombia and western Ecuador. Zeledon's antbird feeds on insects, and regularly follows swarms of army ants in order to catch prey flushed by the swarms, but it is not an obligate ant-follower like some species of antbirds.

<span class="mw-page-title-main">Edwin O'Neill Willis</span> American ornithologist

Edwin O'Neill Willis was an American ornithologist who studied the birds of Central and South America.

<i>Neivamyrmex sumichrasti</i> Species of ant

Neivamyrmex sumichrasti is a species of doryline army ant in the genus Neivamyrmex. It is found in Central America, from southern Mexico to Costa Rica.

References

  1. 1 2 Willis, E.; Oniki, Y. (1978). "Birds and Army Ants". Annual Review of Ecology and Systematics. 9: 243–263. doi:10.1146/annurev.es.09.110178.001331. JSTOR   2096750.
  2. Peters, Marcell K.; Likare, Smith; Kraemer, Manfred (2008). "Effects of Habitat Fragmentation and Degradation on Flocks of African Ant-Following Birds". Ecological Applications. 18 (4): 847–58. doi:10.1890/07-1295.1. PMID   18536247.
  3. Wrege, P.H.; Wikelski, M.; Mandel, J.T.; Rassweiler, T.; Couzin, I.D. (2005). "Antbirds parasitize foraging army ants". Ecology. 86 (3): 555–559. doi:10.1890/04-1133.
  4. Ant Army Invasion! – Wild South America – BBC. YouTube (2009-02-27). Retrieved on 2013-02-23.