<P> Almost all antbirds lay two eggs . A few species of antshrike lay three eggs, and a smaller number of antbirds lay one egg, but this is unusual . Small clutch sizes are typical of tropical birds compared to more temperate species of the same size, possibly due to nest predation, although this is disputed . Both parents participate in incubation, although only the female incubates at night . The length of time taken for chicks to hatch is 14--16 days in most species, although some, such as the dusky antbird, can take as long as 20 days . The altricial chicks are born naked and blind . Both parents brood the young until they are able to thermoregulate, although, as with incubation, only the female broods at night . In common with many songbirds, the parents take faecal sacs for disposal away from the nest . Both parents feed the chicks, often bringing large prey items . When the chicks reach fledging age, after 8--15 days, attending parents call their chicks . As each chick leaves the nest it is cared for exclusively from then on by the parent that was present then . After the first chick fledges and leaves with a parent the remaining parent may increase the supply of food to speed up the process of fledging . After fledging, chicks spend the first few days well hidden as the parents bring them food . Chicks of some species may not become independent of the parents for as long as four months in some antwrens, but two months is more typical for the rest of the family . </P> <P> Antbirds are common components of the avifauna of some parts of the Neotropics and are thought to be important in some ecological processes . They are preyed upon by birds of prey, and their tendency to join flocks is thought to provide protection against such predation . The greater round - eared bat preys on some antbird species, such as the white - bibbed antbird and the scaled antbird; the latter is the bat's preferred prey . Nests, including incubating adults, chicks and eggs, are vulnerable to predators, particularly snakes but also nocturnal mammals . Nesting success is low for many species, particularly in areas of fragmented habitat . </P> <P> 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 . 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 . The ant - following antbirds are themselves followed by three species of butterfly in the family Ithomiinae which feed on their droppings . Bird droppings are usually an unpredictable resource in a rainforest, but the regular behaviour of ant followers makes the exploitation of this resource possible . </P> <P> As of April 2008, 38 species are considered by the IUCN to be near threatened or worse and therefore at risk of extinction . Antbirds are neither targeted by the pet trade nor large enough to be hunted; the principal cause of the decline in antbird species is habitat loss . The destruction or modification of forests has several effects on different species of antbirds . The fragmentation of forests into smaller patches affects species that are averse to crossing gaps as small as roads . If these species become locally extinct in a fragment, this reluctance to cross unforested barriers makes their re-establishment unlikely . Smaller forest fragments are unable to sustain mixed - species feeding flocks, leading to local extinctions . Another risk faced by antbirds in fragmented habitat is increased nest predation . An unplanned experiment in fragmentation occurred on Barro Colorado Island, a former hill in Panama that became an isolated island during the flooding caused by the creation of the Panama Canal . Numerous species of antbird formerly resident in the area were extirpated, in no small part due to increased levels of nest predation on the island . While the species lost from Barro Colorado are not globally threatened, they illustrate the vulnerability of species in fragmented habitats and help explain the declines of some species . The majority of threatened species have very small natural ranges . Some are also extremely poorly known; for example the Rio de Janeiro antwren is known only from a single specimen collected in 1982, although there have been unconfirmed reports since 1994 and it is currently listed as critically endangered . Additionally, new species are discovered at regular intervals; the Caatinga antwren was described in 2000, the acre antshrike in 2004, the sincorá antwren in 2007, and the description of a relative of the Paraná antwren discovered in 2005 in the outskirts of São Paulo is being prepared . While not yet scientifically described, conservation efforts have already been necessary, as the site of discovery was set out to be flooded to form a reservoir . Consequently, 72 individuals were captured and transferred to another locality . </P>

The leaves that form a haven for ant nests are called