Sickle-winged Nightjar Eleothreptus anomalus


Justification of Red List Category
This species is thought to have a moderately small population which is declining moderately rapidly owing to habitat loss and degradation. It is therefore classified as Near Threatened.

Population justification
The population is preliminarily estimated to number at least 10,000 individuals, roughly equating to 6,700 mature individuals. This requires confirmation.

Trend justification
A moderately rapid and on-going population decline is suspected owing to habitat loss and degradation.

Distribution and population

Eleothreptus anomalus is very scarce throughout east Paraguay (regular at one site in Misiones and 5-6 other confirmed records) (Hayes 1995, Lowen et al. 1996, Capper et al. 2001) and north Argentina (at least 12 records since 1980), with apparently fragmented populations in central and south-east Brazil (Bornschein et al. 1996, Kirwan et al. 1999). It has also been recorded from Uruguay. Almost all records are of lone individuals, although six individuals were recorded at a wetland site in Rio Grande do Sul recently (Accordi 2002). However, in most cases, there is only a single record from each locality. Some records refer to southern breeders migrating north in the austral winter (Cleere and Nurney 1998).


Most records are from gallery forest, monte (chaco-type woodland) and transitional woodlands, flooded grasslands and patches of chaco-woodland, with islands of Geoffroea decorticans in north-east Argentina. Other noted habitats are in or near savannas and grasslands, marshland, swamps, campo cerrado, lagoon edges with spiny scrub and along streams, pools and flooded palm groves (Straneck and Viñas 1994, Cleere and Nurney 1998, Kirwan et al. 1999), but it is not as associated with water bodies as previously thought (Kirwan et al. 1999).


Chaco-type habitats are threatened by intensive grazing, wildfires and seasonal burning and, in some places, agricultural expansion (Dinerstein et al. 1995). Grasslands are being rapidly destroyed by extensive cattle ranching, agriculture, wetland drainage, excessive use of pesticides and afforestation with Pinus and Eucalyptus spp. (Pearman and Abadie 1995, Lowen et al. 1996).

Conservation actions

Conservation Actions Underway
It is protected by law in Brazil and occurs in Brasília and Serra da Canastra National Parks and Cambuí Biological Reserve. It has been recorded from El Palmar, Diamante, Pilcomayo, Mbrurucuyá and Iguazú National Parks, Argentina, where it is probably a summer migrant (del Hoyo et al. 1999).

Conservation Actions Proposed
Study its precise ecological requirements and seasonal movements. Effectively protect core areas of habitat within its range. Survey current and historical sites.


Text account compilers
Babarskas, M., Benstead, P., Capper, D., Sharpe, C J, Symes, A.

Recommended citation
BirdLife International (2021) Species factsheet: Eleothreptus anomalus. Downloaded from http://www.birdlife.org on 08/12/2021. Recommended citation for factsheets for more than one species: BirdLife International (2021) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 08/12/2021.