Frigatebirds are large, mostly black seabirds, easily identified by their long wingspan, deeply forked tails, and hooked bills. Males have a distinctive red pouch which inflates during the breeding season. These birds are found over tropical oceans and are exceptional fliers, able to stay aloft for weeks using wind currents, mostly hunting for fish and squid. They roost in trees or cliffs, and are known to steal food from other birds, a behavior called kleptoparasitism. Frigatebirds breed in colonies and are known for their long period of parental care; they breed every other year due to this extensive investment in their offspring. There are five existing species, with the magnificent, great, and lesser being widespread, and the Christmas Island and Ascension Island frigatebirds are endangered and found only on their respective islands. The term "frigatebird" itself dates back to the 18th century and stems from the French word for a fast warship, likely because of their fast and agile flight. Their taxonomy is complex, with current genetic studies placing them near the gannets and boobies. Remarkably, frigatebirds can sleep while flying and are long-lived, though their precise lifespan is unknown. Populations vary, with some species at risk due to habitat loss and overfishing, but conservation efforts, particularly the eradication of feral cats on Ascension Island, have seen some positive effects. Historically, frigatebirds have held cultural significance in many island nations, from Nauru to Easter Island.