VU
White-winged Nightjar Eleothreptus candicans



Justification

Justification of Red List Category
This species is currently known from just five sites. The known population is very small. Therefore, the species is classified as Vulnerable. As it may well be found to occur at other sites and the population estimate may have to be revised upwards, the species may qualify for downlisting in the future.

Population justification
The population is estimated to number 1,000-2,499 individuals based on an assessment of known records, descriptions of abundance and range size. This is consistent with recorded population density estimates for congeners or close relatives with a similar body size, and the fact that only a proportion of the range is likely to be occupied. This estimate is equivalent to 667-1,666 mature individuals, rounded here to 600-1,700 mature individuals. However, the estimate is provisional; the population in Brazil may be larger than assumed here (Instituto Chico Mendes de Conservação da Biodiversidade 2018), and hence the population estimate may have to be revised upward if new information becomes available.

Trend justification
The population of White-winged Nightjar is suspected to be in decline based on the large-scale destruction and degradation of cerrado habitat within the whole range and at known sites of occurrence. However, the likely rate of decline has not been estimated.

Distribution and population

White-winged Nightjar occurs in central South America, ranging from Bolivia to Brazil and Paraguay. The species is currently known from five small, disjunct sites. It is found at one locality in northern Bolivia (Beni Biological Station in Beni [Davis and Flores 1994, Grim and Šumbera 2006]), at two localities in south-central Brazil (Emas National Park in Gioás [Rodrigues et al. 1999] and a recently discovered population near Uberaba in Minas Gerais [eBird 2019, A. Lees in litt. 2019]), and two localities in eastern Paraguay (Mbaracayú Forest Nature Reserve in Canindeyú and Laguna Blanca in San Pedro [Lowen et al. 1996, Clay et al. 1998, Pople 2003]). Additionally, there are historical records from Mato Grosso and São Paulo, Brazil, and from Paraguay (de Azara 1805). The species may occur at other sites as well.

For three of the five sites of occurrence, the population size has been estimated. Mbaracayú Forest Nature Reserve (Paraguay) holds c.40-150 individuals, equating to around 25-100 mature individuals (Pople 2003). Laguna Blanca (Paraguay) is suspected to hold at least 30 individuals, or at least 20 mature individuals (Grim and Šumbera 2006). In Bolivia, the sighting of an adult male in 2003 represents the first record at Beni since the initial male was collected in 1987 (Davis and Flores 1994, Grim and Šumbera 2006), suggesting that the population there may be small. The size of the population in Emas National Park (Brazil) is somewhat unclear, however. In the 1980s, the Emas population was assumed to number in the hundreds (if not larger), and density estimates from Mbaracayú suggest that, despite the paucity of recent records from Emas (Rodrigues et al. 1999), this may be an underestimate, as the National Park encompasses large areas of suitable habitat. Given the global population size of this species, it is likely that the population at Emas National Park consists of fewer than 1,000 mature individuals, and possibly even fewer than 250 mature individuals. There are no estimates available for the population near Uberaba.

Ecology

The species occupies open grasslands with scattered trees and bushes (Cleere et al. 2018), preferring dry savannas or open cerrado, often with termite mounds, anthills and palms Butia paraguayensis (Pople 2003, Cleere et al. 2018). It generally avoids areas of tall grass and woodland (Cleere et al. 2018). When foraging, it prefers areas of younger vegetation, perhaps due to the increased insect prey they support (Rodrigues et al. 1999, Pople 2003). The species is apparently sedentary (Pople 2003), although there may be local movements in response to fires. Data from Paraguay suggests that the breeding season extends from September to January (Pople 2003). The breeding system, male nuptial display, nest-site, eggs and chicks have all been described recently (Clay et al. 2000, Pople 2003, Clay et al. 2014, Pople 2014).

Threats

Known populations of this species are relatively well protected. Nevertheless, two-thirds of the cerrado region had been heavily or moderately altered by 1993, with most of the destruction having occurred since 1950 (Cavalcanti 1999, Conservation International 1999). The principal threats are grazing, invasive grasses, inappropriate fire regimes and conversion to agriculture for Eucalyptus plantations, pasture, soybeans and other exportable crops (Stotz et al. 1996, Parker and Willis 1997, Rodrigues et al. 1999, Pople 2003).

Conservation actions

Conservation Actions Underway

The species occurs in several protected areas; Emas National Park, Mbaracayú Forest Nature Reserve and Beni Biological Station. It is protected under Paraguayan law, where it is considered Endangered at the national level (H. del Castillo in litt. 2012). It is protected under Brazilian law, where it is considered Vulnerable at the national level (Instituto Chico Mendes de Conservação da Biodiversidade 2018). A three-year study of its breeding biology, ranging behaviour and habitat use in Paraguay was completed in 2001 (Pople 2003, 2014).

Conservation Actions Proposed

Survey areas of suitable cerrado habitat in Brazil, northeastern Paraguay and Bolivia. Utilise survey techniques developed in Paraguay to estimate the population in Emas. Establish fire management regimes at protected sites, to create and maintain mosaics of vegetation ages, and prevent uncontrollable, destructive wildfires during the breeding season (Pople 2003, Pople and Esquivel 2012). Monitor and control the spread of invasive grass species. Secure further private protected areas within the Cerrado de Laguna Blanca IBA (H. del Castillo in litt. 2012).

Identification

20 cm. Striking, ghostly nightjar. Sandy grey-brown breast and upperparts with vermiculations. Brown face and throat. Off-white moustachial stripe. Dark centre to grey crown. Male has rest of underparts and most of tail white. Central pair of rectrices pale buff. Mostly white wings tipped black, sandy grey-brown inner coverts. Females are browner with dusky barring on tawny-rufous wings and tail. Buff lower underparts. Similar spp. Female Little Nightjar Caprimulgus parvulus is more patterned, with pale throat and distinctive pale spots on wing-coverts. Voice Largely silent, males produce mechanical tuc, trrrrrut noise during display.

Acknowledgements

Text account compilers
Hermes, C., Pople, R., Capper, D., Sharpe, C.J.

Contributors
Cartes, J., Grim, T., Hennessey, A.B., Lees, A. & del Castillo, H.


Recommended citation
BirdLife International (2022) Species factsheet: Eleothreptus candicans. Downloaded from http://www.birdlife.org on 01/12/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 01/12/2022.