The Frigatebirds (Fregatidae) are a family of five species of seabirds, related to pelicans. They are also sometimes called Man of War birds or Pirate birds. They have long wings, tails and bills and the males have a red gular pouch that is inflated during the breeding season to attract a mate.

Frigatebirds are pelagic piscivores which obtain most of their food on the wing. A small amount of their diet is obtained by robbing other seabirds, a behavior that has given the family its name, and by snatching seabird chicks.

Frigatebirds are found over tropical oceans and ride warm updrafts. Therefore, they can often be spotted riding weather fronts and can signal changing weather patterns.

These birds do not swim and cannot walk well, and cannot take off from a flat surface. Lacking the ability to take off from water, they snatch prey from the ocean surface or beach using their long, hooked bills. They catch fish, baby turtles and similar items in this way. Frigatebirds will rob other seabirds such as boobies, tropicbirds, and shearwaters of their catch, using their speed and manoeuvrability to outrun and harass their victims until they regurgitate their stomach contents. Having the largest wingspan to body weight ratio of any bird, they are essentially aerial, able to stay aloft for more than a week, landing only to roost or breed on trees or cliffs.