Endemic to Ascension Island, this distinctive seabird has long wings (196-201cm) and a deeply forked tail. Juvenile birds have a white head and pale belly. Frigatebirds are highly adapted to an aerial lifestyle; they are lightweight for their size and fly efficiently using thermals to soar vast distances. Their plumage is not waterproof so they never land on the ocean, instead using their aerial agility to pluck food from the surface of the ocean or steal food (kleptoparasitize) from other seabirds. They have very short legs suited only for perching and struggle to walk even short distances.

The Ascension frigatebird nests on Boatswainbird Island and on Letterbox peninsula. Males attract females to mate by inflating their large red throat pouch and vibrating their wings. Females lay a single white egg on the ground, with only a few feathers to mark the nest.