The behavior of White-tailed Nightjar is poorly studied. This nightjar is nocturnal. It forages with sallies from the ground or from perches (Stiles and Skutch 1989, Hilty 2003), but also forages in continuous flight low over open grasslands, "wandering or weaving (almost as though floating) around for several min[utes], apparently capturing flying insects" (Hilty 2003). During the day rests on the ground, in the open or among shrubs or grasses (Haverschmidt 1968, Hilty 2003); rarely perches on branches (Stiles and Skutch 1989).
During the peak of the breeding season, the male may sing steadily for several hours, beginning at dusk (Hilty 2003).