The Eastern Whip-poor-will is a medium-sized goatsucker (27 cm length) that feeds on flying insects taken in short sallies from the ground or a branch. An inhabitant of various forest types in the eastern and northeastern United States and southeastern Canada, it sings a sweet, quavering whip-poor-WILL. Like many members of its family, it is most active on moonlit nights when its insect prey is most effectively silhouetted against the bright sky. Large eyes and long sensory rictal bristles surrounding the bill help it locate and capture insects in low light levels. Short wings and a long, rudder-like tail permit the acrobatic flight necessary to catch prey varying in size from a mosquito to a large moth or beetle. Adult Eastern Whip-poor-wills are mottled with black and brown and there are extensive gray areas on the mantle and crown. Males have white corners to the tail and a white throat patch. Unlike some members of its genus, there are no white wing patches. The Eastern Whip-poor-will is migratory, with complete withdrawal from the breeding range. The Eastern Whip-poor-will nests on the ground and lays two eggs. Its nesting cycle is timed to allow maximal feeding of chicks during the full moon period. Like many ground nesting forest birds, Eastern Whip-poor-wills have decreased throughout their range. Factors that may be responsible include fire suppression practices, feral cats, habitat fragmentation, and insecticides. The recently split Mexican Whip-poor-will (Caprimulgus arizonae) is most easily distinguished by voice: its song is a burry purrrple-ríp. This similarly-plumaged southwestern species inhabits montane pine-oak woodlands in west Texas, New Mexico and Arizona, south to Central America.