Antbird - Status and Conservation

Status and Conservation

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.