Which bird can hibernate over the winter months?

Amazingly enough, there is just one species of bird which has been found to hibernate. It is the Common Poorwill which is a nocturnal hunter found in twelve western states of the USA. The Nightjar family of birds is found across most continents and their eerie call and crepuscular habits have made them part of folklore and they often have strange nicknames. In Europe, the Common Nightjar is known as the Goatsucker which proves just how mystical this species is perceived. Whilst the majority of Common Poorwill migrate southwards into Mexico and beyond, there have been a few cases where some birds have been found in a torpid state in caves. This is a unique habit for this mysterious creature.