Frigate Bird Identification

Frigatebirds are large, highly maneuvering seabirds that belong to the order pelecaniformes. Five species exist---all pantropical---that neither walk nor swim, meaning they are airborne for the majority of their lives. Frigatebirds, which have elongated wings and long, forked tails, may be seen soaring high over the ocean before plummeting to steal fish from other birds, including other frigatebirds. Frigatebirds' behavior includes colonial breeding. All males are black and possess a red throat sack, which inflates into a large balloon during courtship.

  1. Differentiating from Other Birds

    • Frigatebirds may appear kite-like from a distance because of their narrow wings and deeply forked tails.
      At closer view, however, the frigatebird's long beak becomes apparent. That, combined with a wingspan of 72 to 94 inches, which dwarfs the body, helps identify the frigatebird. The longer and stiffer-winged albatrosses are generally pale in color, whereas frigatebirds are dark. Pelicans have much broader wings.
      Frigatebirds may also be identified by their piratical behavior of harassing boobies and gulls into surrendering their catch.

    Identifying Magnificent Frigatebirds

    • It is notoriously difficult to distinguish among the five species that make up the family. The largest, the magnificent frigatebird (Fregata magnificens), has a wingspan of nearly 8 feet. It is the species most likely to be seen around the southern coasts of the United States and throughout the tropical Pacific and Atlantic coasts. As in all frigatebirds, sexual dimorphism is expressed. Females are browner than males, while juveniles are always paler. Juvenile and immature plumages last up to six years.

    Identifying Great Frigatebirds

    • Great frigatebirds (Fregata minor) are found around most tropical waters, although they are absent from the Caribbean and the Atlantic coasts of the United States and Africa. Males are very similar to magnificent frigatebird males, but their black is glossed with a green sheen rather than the purple of their larger relatives. The great male also has a gobbling call in contrast to the magnificent frigatebird's rattling sound.
      Females are easier to separate, for while both are black above and on the breast, the great frigatebird has a white throat. Great frigatebirds also have distinctly shorter tails.

    Identifying Lesser Frigatebirds

    • Lessers (Fregata ariel) are smaller than the aforementioned species, with a six foot wingspan. They have a greater amount of white on the underparts and underwing than those species. Males have the same green sheen as the great. The two species also share the same location distribution, except that lessers are absent from the Pacific Coast of the Americas.
      Females more closely resemble a small magnificent frigatebird, but with a more noticeable white collar on the hindneck. The juvenile lesser frigatebird fledges with a rusty head where in other species it is normally white.

    Identifying Ascension and Christmas Frigatebirds

    • The Ascension and Christmas frigatebirds breed only on the respective South Atlantic and Indian Ocean islands from where they get their names, although the Christmas frigatebird (Fregata andrewsi) also disperses to the coasts of Java and Borneo. The male Ascension frigatebird (Fregata aquila) is almost indistinguishable from the male magnificent, except in size: The Ascension is smaller.
      They do not overlap in range. A brownish band extending across the upper breast marks the female, which otherwise closely resembles the male.
      Both sexes of Christmas frigatebirds have more white on the lower belly than other species.