The common poorwill, Phalaenoptilus nuttallii, breeds in the western United States, as well as in small areas of southwestern Canada and northern Mexico. It winters in the southwestern United States and northern Mexico. The common poorwill is common throughout Utah as a breeding species during summer. Its habitats include arid open grassland and shrubland areas. It feeds on night-flying insects, mainly moths and beetles.
This species nests on the ground, laying two eggs in a slight scrape or hollow, often partially shaded by a shrub or rock. Both parents incubate the eggs, which hatch after twenty to twenty-one days. The young, cared for by both parents, first take flight at twenty to twenty-three days after hatching. The parent birds are known to move their eggs or young in response to disturbance.
The common name poorwill is intended to be suggestive of the bird's call. This bird is exceptional in its tolerance for both heat and cold. It readily enters a state of deep torpor in response to cold or hunger, and has been considered to hibernate. This was recognized by the Hopi people long ago, and the Hopi name for this bird, holchoko, means "the sleeping one."