Small nightjar of brushy oak woodland in foothills and highlands; endemic to west Mexico. Heard far more often than seen. Feeds from perches on the ground (including quiet roads) and in trees. Usually sings from a concealed perch. Sexes look similar: cryptic gray-brown to rusty overall with a rather plain face and throat, white "vicar’s collar," white spots on the wings, and narrow white tail tip. Its "ears" are erectile head feathers rarely visible in the field. Loud, resonant whistled "preeOO" song is repeated steadily.