Curve-billed reedhaunter  (Limnornis curvirostris)

Classified as Least Concern (LC) on the IUCN Red List (1).

First collected by Charles Darwin during the voyage of the H.M.S. Beagle (3), the curve-billed reedhaunter is a relatively plain-coloured bird with, as the common name suggests, a long, downward-curving beak (2) (4). The body is relatively robust, with a fairly long, rounded tail (5). The upperparts are brown, more reddish-brown on the wings, rump and tail, with whitish underparts that are tinged buff on the lower breast and flanks, and a conspicuous white line above the eye (2) (4). Males and females are similar in appearance (2). The distinctive loud song, often delivered from a relatively exposed vantage point, consists of a fast series of harsh notes that rise and then fall in pitch, fading towards the end (2) (4). The call is described as a hollow took (2).

Although often previously treated, including by Darwin, as a close relative of the very similar-looking straight-billed reedhaunter (Limnoctites rectirostris), genetic analysis has now confirmed that the two species are not closely related (5).

The curve-billed reedhaunter occurs in southern Uruguay, eastern Argentina and the extreme southeast of Brazil (2) (4) (6).

This species is confined to extensive reedbeds in freshwater marshes and coastal lagoons, below elevations of 100 metres (2) (4) (5).

Usually found alone or in pairs, the curve-billed reedhaunter is a difficult bird to see when not singing, as it typically creeps about amongst cover and rarely flies far (4). Food is gleaned from marsh vegetation and comprises various arthropods, such as ants, grasshoppers, beetles and larvae (2). Presumed to be monogamous, the curve-billed reedhaunter is thought to breed during the spring and summer, building a ball-shaped nest from woven grasses, leaves and fibres. The nest is reported to be attached to reeds or supported by vegetation, and the interior is lined with soft plant material. There is a side entrance, protected by a slight “awning” (2). Two eggs are laid (2), and, unusually for a species in the Furnariidae family, are a deep greenish-blue, rather than white (5).

The curve-billed reedhaunter still has a large range, and is believed to have a large global population (6). However, its conservation status is poorly known, and its specialised habitat requirements may make it potentially vulnerable to habitat loss or alteration (2).

The curve-billed reedhaunter occurs in a number of protected areas, including the Aparados da Serra National Park in Brazil, and Costanera Sur, Ingeniero Otamendi and Ribera Norte Reserves in Argentina (2). There are no known specific conservation measures in place for this species.

View information on this species at the UNEP World Conservation Monitoring Centre.

For more information on the curve-billed reedhaunter see:

• BirdLife International:
  http://www.birdlife.org/datazone/species/index.html?action=SpcHTMDetails.asp&sid=4931&m=0
• del Hoyo, J., Elliott, A. and Sargatal, J. (2003) Handbook of the Birds of the World. Volume 8: Broadbills to Tapaculos. Lynx Edicions, Barcelona.