Systematics

Magnificent Frigatebird now considered monotypic species (Mayr and Cottrell 1979). Formerly considered to have 3 subspecies with largest birds in Cape Verde Is. and Galápagos Is. (Murphy 1936). Races formerly recognized: F. m. magnificens in the Galápagos; F. m. rothschildi in e. Pacific, Caribbean, Florida, w. Atlantic; and F. m. lowei in Cape Verde Is. Wetmore (1965) claimed measurements showed no significant differences throughout the range, but combined all w. Atlantic and Caribbean birds to calculate mean culmen length and mass; these birds are shown in Table 1 to have significant size and mass variation between islands as close as British Virgin Is. and Barbuda (EAS), but this needs further study. Egg size differs significantly among colonies within Caribbean (see Table 2). Few specimens exist and no study of morphology throughout range has been done. In light of differences within Caribbean region alone, subspecific definitions need further study.

Disputes over nomenclature and lack of information on birds in some areas have resulted in incorrect descriptions of frigate species and ranges in the literature. Five species of frigatebird in family, Magnificent the largest; all species classified in a single genus, Fregata, and distributed throughout tropical oceans (see Mayr and Cottrell 1979, Harrison 1983). Other species include: Ascension Island (F. aquila), Great, Lesser, and Christmas Island (F. andrewsi) frigatebirds.