Data Zone
Justification of Red List category
The species is endemic to a small range in Puerto Rico. In recent years, hurricanes have caused considerable destruction of forests in Puerto Rico, albeit not yet within this species' range. Considering the substantial risk of large-scale habitat damage also within its range in the near future due to an increased intensity and possibly frequency of hurricanes as a consequence of climate change, and the species' susceptibility to forest loss, it is assessed as Vulnerable.
Population justification
Based on transect counts in three sites (Guanicá, Susúa and Guayanilla), the average population density was estimated at 0.86-1.73 individuals/ha (Gónzález 2010). This value may however be overly optimistic as the study was carried out at the species' strongholds (Gónzález 2010); consequently, densities in other parts of the range may be lower (see eBird 2023). It is therefore precautionarily assumed that only 25% of the forests within the range are occupied at this density (i.e., c.4,800-8,600 ha; Global Forest Watch 2023). Based on these assumptions, the global population may number around 4,100-14,900 individuals. This roughly equates to 2,700-9,900 mature individuals.
Trend justification
The population trend has not been quantified, but declines are suspected on the basis of the slow loss and degradation of its preferred dry forest habitat.
Tree cover loss within the range is currently low (2-3% over three generations; Global Forest Watch 2023, using Hansen et al. [2013] data and methods disclosed therein). Even though the species shows a strong preference for dry forests and occurs at much lower densities in open, shrubby and secondary habitats, the low rate of tree cover loss is unlikely to be driving major declines. Tentatively, it is suspected that current population declines do not exceed 5% over three generations.
This species is endemic to Puerto Rico (to U.S.A.). While it probably formerly occupied large areas of the island, it is now restricted mainly to the lowlands and lower montane zones on the south and south-west.
The species prefers dry, deciduous and evergreen forests (Vilella 2020, Castro-Prieto et al. 2021). It is presently more abundant in closed canopy dry forest on limestone soils. It occurs at lower densities in moist and wet forests, in dry, open, scrubby secondary growth, xeric or dry scrubland, open scrub-forest and thorny forest undergrowth, with a few birds in plantations (Cleere and Nurney 1998).
Breeding occurs mainly between February and June (Vilella 1995, Castro-Prieto et al. 2021). Nests are placed directly onto a deep layer of leaf litter in forests (Vilella 2008, 2020). 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).
Habitat loss and degradation are major threats, especially from residential, industrial and recreational expansion (Vilella 1995). Nests and chicks may be may be predated by fire-ants (Solenopsis spp.), introduced mongoose (Herpestes auripunctatus) and feral cats (Felis catus) (Cleere and Nurney 1998, Castro-Prieto et al. 2021). The spread of non-native Red-tailed Boas (Boa constrictor) in southern Puerto Rico may further threaten the species (A. L. Morales-Pérez in litt. 2023).
The species may initially benefit from tropical storms and hurricanes as they are believed to facilitate dispersal (Vilella 2020). There are no survey data indicating how the population reacted to the impacts of major hurricanes of category 4 and higher (see Lloyd et al. 2019, Irizarry et al. 2021); however, its strong preference for dry forest, susceptibility to habitat degradation and loss and very small range suggest that the projected increase in intensity and probably frequency of hurricanes in the Caribbean (see e.g. Knutson et al. 2010, Walsh et al. 2016) can quickly cause substantial losses of forested habitat and severely impact the population size.
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 species is covered by a multi-species action plan (Puerto Rico Department of Natural and Environmental Resources 2015).
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 Antrostomus 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).
Text account compilers
Hermes, C.
Contributors
Benstead, P., Bird, J., Butchart, S., Calvert, R., Capper, D., Cleere, N., Colón López, S., Delannoy, C.A., Khwaja, N., Morales, A.L., Sharpe, C.J., Symes, A., Taylor, J., Vilella, F.J., Wege, D. & Wheatley, H.
Recommended citation
BirdLife International (2024) Species factsheet: Puerto Rican Nightjar Antrostomus noctitherus. Downloaded from
https://datazone.birdlife.org/species/factsheet/puerto-rican-nightjar-antrostomus-noctitherus on 23/11/2024.
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 23/11/2024.