- The Common Poorwill (Phalaenoptilus Nuttallii) is a common yet highly elusive nocturnal nightjar that thrives across the diverse habitats of southern Arizona - Their mottled gray-brown feathers resemble tree bark or desert soil ... they blend seamlessly into rocky slopes and sandy terrains - It is the only North American bird known to enter an extended state of torpor ... when temperatures drop and flying insects vanish, their body temperature can plummet to 40°F, allowing them to hibernate in rock crevices for weeks - Unlike the wide-sweeping flight of nighthawks, a poorwill sits quietly on open ground or low perches ... it scans the moonlit sky for insect silhouettes, then flutters straight up to ambush beetles and moths - They do not build typical nests ... instead, they lay two eggs directly onto bare ground or leaf litter, relying completely on camouflage for protection - Because they are strictly nocturnal, your best asset is your ears ... listen for their clear, whist...