Clearly, additional studies are needed to better understand the breeding behavior of caprimulgids in general and Chuck-will's-widows specifically.
Among caprimulgids, clutch sizes are generally either one or two (Cleere 1999).
Little is known about the brooding behavior of other caprimulgids.
The extent to which vocalizing may restrict foraging by caprimulgids is uncertain, but males deplete fat reserves during the breeding season whereas females, which probably call infrequently, do not (Csada and Brigham 1992, Thomas et al.
Whether specific predators and or predator foraging strategies are the major selective pressures which have shaped the differences in response to lunar conditions between caprimulgids and some rodents, remains to be understood.