{{Short description|Type of bird}} [[Image:Gymnopithys-leucaspis-001 edit2.jpg|thumb|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.<ref name = "Willis">{{cite journal|author1=Willis, E. |author2=Oniki, Y. |year=1978|jstor=2096750 |title=Birds and Army Ants|journal= Annual Review of Ecology and Systematics|volume=9|issue=1 |pages= 243–263|doi=10.1146/annurev.es.09.110178.001331|bibcode=1978AnRES...9..243W }}</ref> The best-known ant-followers are 18 species of antbirds 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, regularly feeding away from the swarms as well.{{citation needed|date=June 2025}}
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'',<ref name = "Willis"/> 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''.<ref>{{cite journal|doi=10.1890/07-1295.1|title=Effects of Habitat Fragmentation and Degradation on Flocks of African Ant-Following Birds|year=2008|last1=Peters|first1=Marcell K.|last2=Likare|first2=Smith|last3=Kraemer|first3=Manfred|journal=Ecological Applications|volume=18|issue=4|pages=847–58|pmid=18536247|bibcode=2008EcoAp..18..847P }}</ref>
In 1978, Willis and Oniki suggested that the relationship between the 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.<ref>{{cite journal |last1=Willis |first1=E. |last2=Oniki |first2=Y. |title=Birds and Army Ants |journal= Annual Review of Ecology and Systematics|date=1978 |volume=9 |issue=9|page=243 |doi=10.1146/annurev.es.09.110178.001331 |bibcode=1978AnRES...9..243W }}</ref> 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.<ref>{{cite journal|author1=Wrege, P.H. |author2=Wikelski, M. |author3=Mandel, J.T. |author4=Rassweiler, T. |author5=Couzin, I.D. |year=2005|title=Antbirds parasitize foraging army ants|journal=Ecology|volume=86|issue=3|pages=555–559|doi=10.1890/04-1133|bibcode=2005Ecol...86..555W }}</ref> This has resulted in a number of behaviours by the ants in order to reduce kleptoparasitism, including hiding secured prey in leaf litter and caching food on trails. It has been suggested{{by whom|date=June 2025}} 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 few as four stings from fire ants.<ref>[https://www.youtube.com/watch?v=DXaaTQztoI0 Ant Army Invasion! – Wild South America – BBC]. YouTube (2009-02-27). Retrieved on 2013-02-23.</ref>
==References== {{Reflist}}
Category:Bird behavior Category:Biological pest control Category:Ants