Current view: Data table and detailed info
Taxonomic source(s)
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A. and Fishpool, L.D.C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 1: Non-passerines. Lynx Edicions BirdLife International, Barcelona, Spain and Cambridge, UK.
SACC. 2005 and updates. A classification of the bird species of South America. Available at: https://www.museum.lsu.edu/~Remsen/SACCBaseline.htm.
IUCN Red List criteria met and history
Red List criteria met
Red List history
| Migratory status |
unknown |
Forest dependency |
low |
| Land-mass type |
continent
|
Average mass |
- |
Population justification: It appears to be scarce and localised (Pearman and Abadie 1995). Almost all records are of lone individuals, although six individuals were recorded at a wetland site in Rio Grande do Sul (Accordi 2002), the species is observed daily at Reserva Natural Rincón de Santa María, Corrientes (Fariña et al. 2018, Bodrati et al. 2019), and there are known populations at Campo San Juan, Misiones, and possibly at Reserva Natural Provincial Iberá, Corrientes (A. Bodrati, N. Fariña and K. Cockle in litt. 2021). However, the species's apparently scarcity may result at least partially from it being a cryptic, nocturnal species that is often difficult to study. Surveys from 1999-2006 in the coastal plain of Rio Grande do Sul estimated a population of 12 breeding pairs at Capao Novo (218 ha), and 20 breeding pairs at Banhado dos Pachecos (2,544 ha; Accordi 2008).
Based on the minimum and first quartile densities estimates of other nightjar species (0.3 and 0.9 individuals/km2, respectively), the area of the mapped extant range, and assuming 3-10% occupancy, the population size may be calculated to fall within the range 5,000 - 52,000 individuals. However, given the small number of records, the true population size is suspected to be smaller than this (K. Cockle in litt. 2020), so it is here placed in the band 2,500 - 52,000 individuals.
The subpopulation structure is not known, but based on the disjunct range, there are assumed to be at least three subpopulations.
Trend justification: The species's range appears to have contracted considerably over recent decades, so the species's population size is inferred to be declining. It is suspected that the species has lost around half of its range in Argentina over 25 years since the 1990s (A. Bodrati, N. Fariña and K. Cockle in litt. 2021). It is almost certainly extirpated from Buenos Aires, and almost all habitat in Entre Rios has been destroyed (A. Bodrati, N. Fariña and K. Cockle in litt. 2021). The species was recorded in Santiago del Estero (M. Rumboll in litt. 1986), El Palmar National Park, Entre Rios, in 1985 (M. Nares and D. Yzurieta in litt. 1986), and Colon, Entre Rios in 1979 (M. Nares and D. Yzurieta in litt. 1986). In the 1990s, four records were made at three sites in Sao Paulo State, Brazil (Kirwan et al. 1999). In the absence of recent records, the species is now presumed to be locally extinct in all of these regions. The species was known to occur at Puerta Boca, Entre Rios, until around 2000, but the wetland habitat there has since been destroyed (A. Bodrati, N. Fariña and K. Cockle in litt. 2021).
Based on the reduction of the area of the mapped extant range, the species is estimated to have lost approximately 60% of its range since the 1980s. Assuming a constant rate of habitat loss, the species is suspected to have undergone a reduction of 10-19% over the past decade. Assuming that the same area of range continues to be lost per year, up to 46% of the species's remaining range may be lost over the next ten years, so an equivalent population reduction is suspected.
Country/territory distribution
Important Bird and Biodiversity Areas (IBA)
Recommended citation
BirdLife International (2024) Species factsheet: Sickle-winged Nightjar Eleothreptus anomalus. Downloaded from
https://datazone.birdlife.org/species/factsheet/sickle-winged-nightjar-eleothreptus-anomalus on 22/12/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from
https://datazone.birdlife.org/species/search on 22/12/2024.
