|Scientific Name:||Caprimulgus noctitherus|
|Species Authority:||(Wetmore, 1919)|
|Red List Category & Criteria:||Endangered B1ab(i,ii,iii,v) ver 3.1|
|Reviewer/s:||Butchart, S. & Symes, A.|
|Contributor/s:||Cleere, N., Colón López, S., Delannoy, C. & Vilella, F.|
This species qualifies as Endangered because it has a very small range, which is severely fragmented, and in decline.
|Range Description:||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).|
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||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.|
|Habitat and Ecology:||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).
|Citation:||BirdLife International 2012. Caprimulgus noctitherus. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. <www.iucnredlist.org>. Downloaded on 26 May 2013.|
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