Common Poorwill, ( Phalaenoptilus nuttallii ) -the only bird known to go into hibernation picture courtesy Google images Hibernation is a way animals conserve energy to survive adverse weather conditions or lack of food. Usually, birds don't hibernate! The common poorwill is the only bird known to go into hibernation, a state in which metabolism and body temperature are reduced for weeks or even months. For this Hopi Native Americans called the bird "the sleeping one". While some hummingbirds experience daily, short-term torpor in order to conserve energy, the Common Poorwill is the only bird known to have long bouts of it. During the winter when its food becomes scarce instead of migrating to a warmer climate like most birds do, the Poor-wills will go into a state of inactivity so that it can survive several weeks or months without eating. picture courtesy Google images Common Poorwills are native to Canada, United States and Mexico.