ABSTRACT
This chapter describes two groups of nightjars: Chordeilinae (nighthawks) and Caprimulginae (nightjars), although these two groups may not be reciprocally monophyletic. Ecologically, these two groupings are convenient: "nighthawks" are typically fast-flying aerial insectivores that have very short rictal bristles, whereas "nightjars" sally large insects from the ground or low branches and generally have long rictal bristles. Nightjars and nighthawks have cryptic plumage, acting as camouflage for resting during the day. To the knowledge, most, if not all, caprimulgids follow a Complex Basic Strategy. Preformative molts are often partial, but may be highly variable within species with some individuals replacing only body feathers and others replacing a considerable number of secondary coverts, but rarely flight feathers. Primary and secondary molt often follows the typical replacement sequence, although in some species a Staffelmauser replacement pattern occurs, perhaps being more likely in larger and/or tropical species.
