Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. The Bermuda Petrel, Pterodroma cahow, is a gadfly petrel. Commonly known in Bermuda as the Cahow, a name derived from its eerie cries, this nocturnal ground-nesting seabird is the national bird of Bermuda, and a symbol of hope for nature conservation. It was thought extinct for 330 years. Its dramatic rediscovery as a "Lazarus species", that is, a species found to be alive after being considered extinct for centuries, has inspired documentary filmmakers.