Breeding interval Female magnificent frigatebirds breed biannually, males attempt to breed annually.gonochoric/gonochoristic/dioecious (sexes separate).( Diamond and Schreiber, 2002 Diamond, 1973 Trivelpiece and Ferraris, 1987) Age of sexual maturity is not known but none breed until plumage is in mature phase. Juveniles near mature mass before fledging. Males rarely care for their young longer than six months and breed annually.

Because female parent involvement continues for much longer than male parental involvement, females only mate every other year. The incubation period for this species is not recorded, but has been estimated at 50 days. ( Diamond and Schreiber, 2002 Diamond, 1973 Madsen, et al., 2004)įemale magnificent frigatebirds lay a single egg three to four weeks after the beginning of breeding season. However, they rarely maintain the same partner from season to season. Magnificent frigatebirds form monogamous pairs each breeding season once females have selected mates. As females attempt to find a preferred mate, males twist and bend to make their gular sac look as large a possible, they also make a loud, drumming noise during this display. They stretch their wings out and throw their heads back for maximum display of the gular sac. Males rapidly vibrate their wings and sit back on their tails. These sacs, while inflated, can get so large that they obscure the bird's head. They inflate their large, red, gular sacs.

Range wingspan 90 to 230 cm 35.43 to 90.55 inĭuring the breeding season, male magnificent frigatebirds congregate at male display sites.

They have short legs and small feet not well-suited to walking or swimming. They are also recognizable by their large size and long, hooked bill. They are most often seen soaring along coastlines at higher altitudes and their silhouette is readily recognizable. Their large heads, long, pointed, narrow wings, and forked tails make them easy to distinguish even from a distance. Their legs, feet, and bill are light-bluish gray. Immature magnificent frigatebirds have a white head and chest while the rest of the body is black. Females are, in general, 15% larger than males. Their legs and feet are flesh-colored or pink, and they lack a gular sac. Females are also entirely black with a white chest and white and tan markings on the wings. Their legs and feet appear back or grayish. They also have faint purple gloss on the head and green on the neck, scapulars, and upper wing. 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. ( Diamond and Schreiber, 2002 Diamond, 1973) A colony with about 2500 pairs of birds in Barbuda, a small island in the Caribbean, is the largest known colony. A colony of magnificent frigatebirds can occupy about 500 m of shoreline with a total area of about 22,500 m squared. They are usually fully exposed to the sun for the birds' sunning habits. Nests are flat or slightly hollow with a diameter of 25 - 35 cm.

Nests are primarily constructed at ground level, but sometimes in trees as well.

Males gather twigs and other nest building materials while females remain at the males' display site and build the nest there. Magnificent frigatebirds usually build their nests out of twigs on or around low-lying vegetation. ( Diamond and Schreiber, 2002 Stefferud, 1966) They are especially common in southern Florida, the Gulf Coast, the Caribbean islands and the west coast of Mexico. They breed as far north as 25 degrees north latitude in Mexico and Florida and as far south 27 degrees south latitude in Brazil. Magnificent frigatebirds live along American, tropical coastlines.

Magnificent frigate bird