Male magnificent frigatebirds are entirely black except for brown inner secondaries on the upper wing and the presence of a red inflatable throat pouch called a gular sac. They also have faint purple gloss on the head and green on the neck, scapulars, and upper wing. Their legs and feet appear back or grayish. Females are also entirely black with a white chest and white and tan markings on the wings. Their legs and feet are flesh-colored or pink, and they lack a gular sac. Females are, in general, 15% larger than males. Immature magnificent frigatebirds have a white head and chest while the rest of the body is black. Their legs, feet, and bill are light-bluish gray.
Their large heads, long, pointed, narrow wings, and forked tails make them easy to distinguish even from a distance. They are most often seen soaring along coastlines at higher altitudes and their silhouette is readily recognizable. They are also recognizable by their large size and long, hooked bill. They have short legs and small feet not well-suited to walking or swimming.
Range mass: 1360 to 1815 g.
Range length: 100 to 230 cm.
Range wingspan: 90 to 230 cm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: female larger; sexes colored or patterned differently; male more colorful; ornamentation