Puerto Rican Nightjar
Puerto Rican Nightjar
|Listed||June 4, 1973|
|Description||A robin-sized, nocturnal, aerially foraging bird.|
|Habitat||Dry tropical forest on limestone.|
|Food||Catches flying insects.|
|Reproduction||Lays eggs on the ground; both parents incubate and care for the young.|
|Threats||Habitat destruction by conversion to residential and agricultural land-uses, and predation by introduced mongooses.|
The Puerto Rican nightjar (Puerto Rican whip-poor-will) is a robin-sized, nocturnal bird with long bristles about the mouth, and fluffy plumage variegated with a mottling of dark brown, black, and gray. There is a white band across the throat and white spots at the ends of the tail feathers.
The Puerto Rican nightjar captures flying insect prey by sallying forth from perches well above the ground. Individuals have favorite perches that are used regularly for feeding in the evening. Nesting occurs from late February through early July, but the peak is from April to June. Calling occurs during all months of the year, but is least during September and October and peaks during April and May. The Puerto Rican nightjar does not construct a nest but rather the eggs are laid directly on leaf litter under vegetation having a canopy 13-20 ft (4-6 m) in height. The average clutch size is two eggs. Incubation requires about 19 days and is done by both the male and the female. The young are able to fly by the fourteenth day after hatching.
The Puerto Rican nightjar is presently found only in the dry limestone forests. In the Susua area it occurs primarily on southern slopes, but is also found in mature lower cordillera forest at somewhat higher elevations. In the Guanica Forest, where the species is most common, it occurs at elevations ranging from sea level to 750 ft (230 m). The breeding density is highest in deciduous forest, evergreen forest, and plantations; however, the species was consistently heard singing below 75 ft (25 m) on the southern slopes near the coast and at the forest's edge.
The Puerto Rican nightjar is found only on the island of Puerto Rico. Its historical distribution included moist limestone forest of the northwest coast. The most recent records are all from dry limestone forest of the southwestern coast, including populations in the Guanica Commonwealth Forest area, the hills above Guayanilla, and the Susua Commonwealth Forest. Recent estimates for all populations are 676 nightjars on about 4,000 acres (10,000 hectares) surveyed, including: Susua-Maricao (141), Guanica (347), and Guayanilla-Peñueles (188). Densities were highest in the deciduous forest, evergreen forest, and plantations in Guanica (Vilella 1989).
The greatest threats to the Puerto Rican nightjar are the continuing destruction and degradation of its habitat for urban, industrial, and tourist developments. The mongoose (Herpestes javanicus ), introduced to Puerto Rico in 1877, may have extirpated the nightjar from areas of its former range with sufficient rainfall and standing water to support mongooses.
Conservation and Recovery
Survival of the Puerto Rican nightjar will depend on preserving and maintaining its critical habitat, particularly in the Guanica Forest and on adjacent privately-owned lands, as well as on the privately-owned lands in the Guayanilla-Peñueles area.
U.S. Fish and Wildlife Service
Boquerón Ecological Services Field Office
Boquerón, Puerto Rico 00622-0491
Telephone: (787) 851-7297
Fax: (787) 851 7440
Kepler, C. B. and A. K. Kepler. 1973. "The distribution and ecology of the Puerto Rican whip-poor-will, and endangered species." Living Bird, Eleventh Annual. Cornell Laboratory of Ornithology, Ithaca, NY.
Vilella, F. J. 1989. "The Reproductive Ecology and Population Biology of the Puerto Rican Nightjar (Caprimulgus noctitherus )." Final Report, Unit Cooperative Agreement No. 14-16-0009-1526. Louisiana State University, Baton Rouge, Louisiana.
U.S. Department of the Interior. 1978. "Species Accounts for Sensitive Wildlife Information System (SWIS)." Fish and Wildlife Service, National Fish and Wildlife Laboratory. Washington, D.C.
U.S. Fish and Wildlife Service. 1984. "Puerto Rican Whip-poor-will Recovery Plan." Atlanta, Georgia. 16 pp.