The Whip-poor-will or whippoorwill, Caprimulgus vociferus, is a medium-sized (22-27 cm) nightjar from North and Central America. The Whip-poor-will is commonly heard within its range, but less often seen. It is named onomatopoeically after its call. This bird is sometimes confused with the related Chuck-will’s-widow (Caprimulgus carolinensis) which has a similar but lower-pitched and slower call. Adults have mottled plumage: the upperparts are grey, black and brown; the lower parts are grey and black. They have a very short bill and a black throat. Males have a white patch below the throat and white tips on the outer tail feathers; in the female, these parts are light brown.
Edward Howe Forbush Useful Birds and Their Protection (Boston, MA: Massachusetts State Board of Agriculture, 1907)