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Puerto Rican Nightjar Antrostomus noctitherus
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This species qualifies as Endangered because it has a very small range, which is severely fragmented, and in decline.

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.

Taxonomic note
Antrostomus noctitherus (del Hoyo and Collar 2014) was previously placed in the genus Caprimulgus.

Caprimulgus noctitherus (Wetmore, 1919)

22 cm. Mottled grey, brown and black nightjar. Black throat bordered by white band. White in outertail. Female similar, but buff throat-band and outertail. Similar spp. Chuck-will's-widow C. carolinensis (northern migrant in winter) is larger, more reddish and has less white in tail. Antillean Nighthawk Chordeiles gundlachii has distinctive white patch in wing. Voice Sequence of emphatic whistles whip whip whip ... (between 2-15 notes, males may also sing continuously for several minutes with up to 160 notes).

Distribution and population
Caprimulgus noctitherus probably formerly occupied large areas of Puerto Rico (to U.S.A.), but its current distribution was recently thought to be restricted to the south-west, notably Susúa-Maricao, Guayanilla-Peñuelas and Guánica-Bermeja. However, recent survey work confirms that its range extends from Ponce through south-central Puerto Rico to Guayama province in the south-east (Vilella and González 2009). There are further recent records from the Parguera Hills and Sierra Bermeja, c.10 km west of Parguera. Studies in 1985-1987, 1989-1990 and 1992 found 712 singing males in 98 km2 of fragmented habitat, with 347 in the Guánica area, 177 in the Susúa-Maricao area and 188 in the Guayanilla area. The population was consequently estimated at 1,400-2,000 individuals, which is similar to the 1984 population estimate of 670-800 pairs (Vilella and Zwank 1993a).

Population justification
The estimate of 930-1,300 mature individuals (roughly equivalent to 1,400-2,000 individuals in total) was estimated based on 712 calling males found within 66% of the suitable habitat within its known range.

Trend justification
This species's population is suspected to be in decline owing to the continued loss and degradation of its habitat for residential, industrial and recreational development, amongst other related and unrelated threats.

The historical range probably comprised moist limestone and coastal forest in northern Puerto Rico, as well as currently occupied dry limestone forest, drier sections of the lower cordillera forest and perhaps dry coastal forest. It is presently more abundant in closed canopy dry forest on limestone soils, composed mainly of semi-deciduous hardwood trees with abundant leaf litter and an open understorey (little or no ground vegetation) at elevations up to 620 m, but more commonly above 75 m. It occurs at lower densities in dry, open, scrubby secondary growth, xeric or dry scrubland, open scrub-forest and thorny forest undergrowth, with a few birds in Eucalyptus robusta plantations (Cleere and Nurney 1998). Breeding occurs between late February and early July, mainly between April and June (Vilella 1995). Nests are common at elevations above 100 m and are characterised by a deep layer of leaf litter and an open midstorey beneath a closed canopy (Vilella 2008). Birds are perhaps permanently territorial, exhibiting strong interannual site fidelity. In Guánica forest, c.87% of nests in one year produced at least one fledgling (Vilella 1995). It feeds on beetles, moths and other insects (Cleere and Nurney 1998).

The introduction of the mongoose in 1877 may have contributed to the initial drastic population decline (there are no data on what the initial effect was), but the differing habitat preferences of the two species suggests very little overlap in their current ranges (Vilella and Zwank 1993b). Habitat loss and degradation now have more significant impacts, especially from residential, industrial and recreational expansion, with concomitant increases in disturbance and fire risk (Vilella 1995). Grass fires started by local people occasionally spread to adjacent forest, with fires that occur during periods of low rainfall being particularly damaging (S. A. Colón López in litt. 2011). A proposed windfarm development in the Karso del Sur IBA has the potential to wipe out 5% of the total breeding population (Anon. 2007). Young birds are predated by Short-eared Owl Asio flammeus, and young and eggs may be predated by Pearly-eyed Thrasher Margarops fuscatus, fire-ants and feral cats (Cleere and Nurney 1998). The proposed construction of a natural gas pipeline in the Guayanilla Hills would create significant disturbance to breeding nightjars and destroy and fragment tracts of the species's habitat (C. A. Delannoy in litt. 2012).

Conservation Actions Underway
It is legally protected. Guánica, Susúa and Maricao are public lands designated as state forests, and Guánica is a biosphere reserve. The Conservation Trust of Puerto Rico has acquired lands in the Guayanilla-Peñuelas region; this area includes mature dry forest where nightjars are abundant. The latter constitutes the only protected nightjar habitat in this portion of its range. The population is surveyed regularly and spatial analysis is being used to identify areas of potentially suitable habitat for protection and examine changes in habitat cover over time (F. J. Vilella in litt. 2007). As part of BirdLife International's Preventing Extinctions Programme the Sociedad Ornitológica Puertorriqueña, Inc. have been designated as Species Guardian and have produced a revised species action plan in collaboration with the U.S. Fish and Wildlife Service. A survey of occupancy of habitat in order to establish current range was carried out by Mississippi State University between March and May 2009 (Vilella and González 2009). The priority conservation actions identified by the species action plan will be implemented through a newly-established Puerto Rican Nightjar Conservation Network and facilitated by the Species Guardian. Conservation Actions Proposed
Survey to identify additional areas for protection, particularly in the newly-established regions of its range in south-central and south-eastern Puerto Rico. Assess population size in newly-established regions of its range. Monitor to assess population trends and the effects of management. Study movements and dispersal patterns. Research breeding biology and life history parameters to develop population models and enable use of population viability analyses. Effectively conserve existing reserves. Reforest disturbed areas with native and selected plantation species. Acquire privately owned tracts of mature dry limestone forest (Vilella 1995). Lobby for priority site conservation through existing initiatives and site support groups (Vilella and González 2009). Create a new dry forest reserve in the Guayanilla Hills (González 2010).

Related state of the world's birds case studies

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.

González, R. G. 2010. Population estimation and landscape ecology of the Puerto Rican Nightjar. Department of Wildlife, Fisheries and Aquaculture, Mississippi State University.

Noble, R. E.; Vilella, F. J.; Zwank, P. J. 1986. Status of the endangered Puerto Rican Nightjar in 1985. Caribbean Journal of Science 22: 137-143.

Vilella, F. J. 1995. Reproductive ecology and behaviour of the Puerto Rican Nightjar Caprimulgus noctitherus. Bird Conservation International 5: 349-366.

Vilella, F. J. 2008. Nest habitat use of the Puerto Rican Nightjar (Caprimulgus noctitherus) in Guánica Biosphere Reserve. Bird Conservation International 18(4): 307-317.

Vilella, F. J., and R. González. 2009. Geographic distribution of the Puerto Rican Nightjar: a patch occupancy approach. Final report, Cooperative Agreement 011406-001. . USGS Cooperative Research Unit, Mississippi State University., Mississippi State, Mississippi.

Vilella, F. J.; Zwank, P. J. 1993. Ecology of the small indian mongoose in a coastal dry forest of Puerto Rico where sympatric with the Puerto Rican Nightjar. Caribbean Journal of Science 29((1-2)): 24-29.

Vilella, F. J.; Zwank, P. J. 1993. Geographic distribution and abundance of the Puerto Rican Nightjar. Journal of Field Ornithology 64: 223-238.

Further web sources of information
Detailed species account from the Threatened birds of the Americas: the BirdLife International Red Data Book (BirdLife International 1992). Please note taxonomic treatment and IUCN Red List category may have changed since publication.

Detailed species account from the Threatened birds of the Americas: the BirdLife International Red Data Book (BirdLife International 1992). Please note, taxonomic treatment and IUCN Red List category may have changed since publication.

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

Species Guardian Action Update

Text account compilers
Benstead, P., Bird, J., Butchart, S., Calvert, R., Capper, D., Sharpe, C J, Symes, A., Taylor, J., Wege, D., Khwaja, N.

Colón López, S., Vilella, F., Delannoy, C., Cleere, N.

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

Recommended citation
BirdLife International (2016) Species factsheet: Antrostomus noctitherus. Downloaded from on 28/10/2016. Recommended citation for factsheets for more than one species: BirdLife International (2016) IUCN Red List for birds. Downloaded from on 28/10/2016.

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 Endangered
Family Caprimulgidae (Nightjars)
Species name author (Wetmore, 1919)
Population size 930-1300 mature individuals
Population trend Decreasing
Distribution size (breeding/resident) 290 km2
Country endemic? Yes
Links to further information
- Additional Information on this species