Great Frigatebird

The Great Frigatebird is a wide-ranging tropical seabird found across the Pacific, Indian, and parts of the southern Atlantic Oceans, sharing the family's signature silhouette of long, bowed wings and a deeply forked tail. Adult males are entirely glossy black with a purplish-green sheen and, like other frigatebirds, an inflatable red throat pouch used in courtship display. Females are larger, with a black head, white breast, and a distinctive reddish eye-ring, while juveniles have rusty-orange heads that fade with age.

Remarkably light for their size, Great Frigatebirds can remain aloft for days at a time, riding thermals and trade winds over tropical seas with minimal effort.

Key field marks

• Long, angular wings and deeply forked tail
• Glossy black plumage in males with a purple-green sheen
• Females have a white breast and pale grey throat, with a reddish eye-ring
• Juveniles show a rusty-orange or tawny head

Similar species

• Lesser Frigatebird is smaller with white "spur" patches extending onto the flanks/underwing in males and females, which Great Frigatebird lacks.
• Magnificent Frigatebird occurs mainly in the Americas; female Magnificent Frigatebirds lack the reddish eye-ring shown by female Great Frigatebirds.
• Separating frigatebird species at sea can be difficult and often relies on subtle plumage and structural differences best seen in good light.

Great Frigatebirds breed on remote tropical islands across the Pacific and Indian Oceans, including sites in the Galápagos, Hawaii's Northwestern Islands, and numerous Indo-Pacific atolls, as well as isolated islands in the South Atlantic. They require predator-free islands with trees or shrubs for nesting and strong onshore winds to aid takeoff given their limited walking ability.

Foraging ranges can extend hundreds of kilometers from the colony over open ocean, and non-breeding individuals may wander widely across tropical seas.

Behavior

Great Frigatebirds are expert soarers and aerial pirates, harassing boobies, tropicbirds, and other seabirds to steal food, and snatching fish, squid, and even turtle hatchlings from the surface without landing on the water.

Voice

Males rattle their bills against the inflated red pouch and give wavering whistles during courtship; both sexes give harsh, guttural calls at the colony.

Feeding

Flying fish and squid are caught at the surface, supplemented by kleptoparasitized food and occasional opportunistic predation on hatchling sea turtles and unattended seabird eggs or chicks.

Nesting and breeding

Males display in groups, inflating their pouches to attract passing females; a single egg is laid in a stick nest, and chick-rearing is prolonged, often lasting many months to over a year given the difficulty of provisioning enough food.