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Sickle-winged Nightjar Eleothreptus anomalus
BirdLife is updating this factsheet for the 2016 Red List
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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.

Taxonomic source(s)
del Hoyo, J.; Collar, N. J.; Christie, D. A.; Elliott, A.; Fishpool, L. D. C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Barcelona, Spain and Cambridge UK: Lynx Edicions and BirdLife International.
SACC. 2006. A classification of the bird species of South America. Available at: #

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).

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.

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 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.

Accordi, I. A. 2002. New records of the sickle-winged nightjar, Eleothreptus anomalus (Caprimulgidae), for a Rio Grande do Sul, Brazil wetland. Ararajuba 10: 227-230.

Bornschein, M. R.; Reinert, B. L.; Bocon, R. 1996. A new record of the Sickle-winged Nightjar Eleothreptus anomalus for southern Brazil. Bulletin of the British Ornithologists' Club 116: 125-126.

Capper, D. R.; Clay, R. P.; Madroo, A.; Mazar Barnett, J.; Burfield, J.; Esquivel, E. Z.; Kennedy, C. P.; Perrens, M.; Pople, R. G. 2001. First records, noteworthy observations and new distributional data for birds in Paraguay. Bulletin of the British Ornithologists" Club 121: 23-37.

Capper, D.R., Clay, R.P., Madroño Nieto, A., Mazar Barnett, J., Burfield, I.J., Esquivel, E.Z., Kennedy, C.P., Perrens, M. and Pople, R.G. 2001. First records, noteworthy observations and new distributional data for birds in Paraguay. Bulletin of the British Ornithologists' Club 121: 23-37.

Cleere, N.; Nurney, D. 1998. Nightjars: a guide to nightjars and related nightbirds. Pica Press, Robertsbridge, U.K.

Collar, N. J.; Gonzaga, L. P.; Krabbe, N.; Madroño Nieto, A.; Naranjo, L. G.; Parker, T. A.; Wege, D. C. 1992. Threatened birds of the Americas: the ICBP/IUCN Red Data Book. International Council for Bird Preservation, Cambridge, U.K.

del Hoyo, J.; Elliott, A.; Sargatal, J. 1999. Handbook of the Birds of the World, vol. 5: Barn-owls to Hummingbirds. Lynx Edicions, Barcelona, Spain.

Dinerstein, E.; Olson, D. M.; Graham, D. J.; Webster, A. L.; Primm, S. A.; Bookbinder, M. P.; Ledec, G. 1995. A conservation assesssment of the terrestrial ecoregions of Latin America and the Caribbean. World Bank, Washington, D.C.

Hayes, F. E. 1995. Status, distribution and biogeography of the birds of Paraguay. American Birding Association, Colorado Springs.

Kirwan, G. M.; Martuscelli, P.; Silveira, L. F.; Williams, R. S. R. 1999. Recent records of the Sickle-winged Nightjar Eleopthreptus anomalus. Bulletin of the British Ornithologists' Club 119: 202-206.

Lowen, J. C.; Bartrina, L.; Clay, R. P.; Tobias, J. A. 1996. Biological surveys and conservation priorities in eastern Paraguay (the final reports of Projects Canopy '92 and Yacutinga '95). CSB Conservation, Cambridge, U.K.

Pearman, M.; Abadie, E. I. Undated. Mesopotamia grasslands and wetlands survey, 1991--1993: conservation of threatened birds and habitat in north-east Argentina.

Straneck, R. J.; Vinas, M. J. 1994. Comentários sobre costumbres y manifestaciones acústicas del atajacaminos de los Pantanos, Eleothreptus anomalus (Gould, 1838) (Aves: Caprimulgidae). Nótulas Faunísticas 67: 1-4.

Further web sources of information
Explore HBW Alive for further information on this species

Recuento detallado de la especie tomado del libro Aves Amenazadas de las Americas, Libro Rojo de BirdLife International (BirdLife International 1992). Nota: la taxonomoía y la categoría de la Lista Roja de la UICN pudo haber cambiado desde esta publicación.

Search for photos and videos, and hear sounds of this species from the Internet Bird Collection

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

IUCN Red List evaluators
Butchart, S., Symes, A.

Recommended citation
BirdLife International (2016) Species factsheet: Eleothreptus anomalus. Downloaded from on 20/10/2016. Recommended citation for factsheets for more than one species: BirdLife International (2016) IUCN Red List for birds. Downloaded from on 20/10/2016.

This information is based upon, and updates, the information published in BirdLife International (2000) Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004) Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.

To provide new information to update this factsheet or to correct any errors, please email BirdLife

To contribute to discussions on the evaluation of the IUCN Red List status of Globally Threatened Birds, please visit BirdLife's Globally Threatened Bird Forums.

Key facts
Current IUCN Red List category Near Threatened
Family Caprimulgidae (Nightjars)
Species name author (Gould, 1838)
Population size 6700 mature individuals
Population trend Decreasing
Distribution size (breeding/resident) 910,000 km2
Country endemic? No
Links to further information
- Additional Information on this species