Goatsuckers


Goatsuckers

 

(Caprimulgiformes), an order of birds. It embraces three families: oilbirds (Steatornithidae; one species, the guácharo), frogmouths (Podargidae), and true nightjars (Caprimulgidae).

True nightjars are crepuscular and nocturnal birds, with long wings and tail; the soft plumage is colored in buff and brown tones. The bill is short, but the slash of the mouth is large (enlarged by the bristles along the edges of the mouth), facilitating the capture of insects. The eyes are large. The legs are short; goatsuckers cannot grasp branches with their digits and perch lengthwise along the branch. Their flight is noiseless. They do not build nests; they usually deposit two eggs in a pit in the earth. When hatched, the nestlings are covered with a dense down and are able to see.

Goatsuckers are distributed principally in the tropics (nonmigratory); only a few species inhabit the temperate zone (migratory). Two species of Caprimulgiformes (Phalaenoptilus nuttallii and Chordeiles acutipennis) that live in North America fall into a torpor in winter (their body temperature at that time drops from 41°C to 18°C). There are eight genera, comprising 72 species. The USSR has three species: the nightjar (Caprimulgus europaeus), which is very widely distributed (in the east to Transbaikalia); the Indian nightjar (C. indicus), which inhabits the forests of southeastern Siberia and southern Primor’e; and the Egyptian nightjar (C. aegyptius), which inhabits the scrub deserts of Middle Asia.

The nightjar’s body length is 26–28 cm, and its weight is 75–100 g. The plumage is sandy-gray with dark varicolored longitudinal markings. In the north it settles along the forest edges (most often pine forests) and in cleared glades; in the south, in deserts and on the slopes of treeless mountains. There are two eggs in a clutch; the brood period is 18 days. Its diet, as in other goatsuckers, consists of insects (butterflies, beetles), which it catches mainly in flight, and, more rarely, on the ground. It is a beneficial bird that exterminates harmful forest insects.

REFERENCE

Ptitsy Sovetskogo Soiuza, vol. 1. Edited by G. P. Dement’ev and N. A. Gladkov. Moscow, 1951.

A. I. IVANOV