Fregata magnificens
magnificent frigatebird

Magnificent frigatebirds live along American, tropical coastlines. They breed as far north as 25 degrees north latitude in Mexico and Florida and as far south 27 degrees south latitude in Brazil. They are especially common in southern Florida, the Gulf Coast, the Caribbean islands and the west coast of Mexico. (Diamond and Schreiber, 2002; Stefferud, 1966)

Magnificent frigatebirds usually build their nests out of twigs on or around low-lying vegetation. Males gather twigs and other nest building materials while females remain at the males' display site and build the nest there. Nests are primarily constructed at ground level, but sometimes in trees as well. Nests are flat or slightly hollow with a diameter of 25 - 35 cm. They are usually fully exposed to the sun for the birds' sunning habits. A colony of magnificent frigatebirds can occupy about 500 m of shoreline with a total area of about 22,500 m squared. A colony with about 2500 pairs of birds in Barbuda, a small island in the Caribbean, is the largest known colony. (Diamond and Schreiber, 2002; Diamond, 1973)

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. (Audubon, 1950; Diamond and Schreiber, 2002; Orr, 1992; UC Regents, 1995)

While there is little data on magnificent frigatebird lifespan, it is estimated at 30 years. Besides natural death, mortality is occasionally caused by destructive hurricanes and man-made interferences in colonies. (Diamond and Schreiber, 2002)

Magnificent frigatebirds are birds of the open ocean. Although their nests are on coastal areas, these birds are in flight for a majority of the time. Often they fly long distances over open water far from land. Their wings are so large that flying is nearly effortless. They take advantage of updrafts and can glide for long distances without beating their wings. They use their long, forked tails for maneuvering. They are one of the only birds with the ability to ride out a hurricane's strong winds. While usually solitary in flight, they do nest in colonies with numerous other pairs. While feeding, they can be extremely aggressive towards other animals. They are otherwise docile and while on land will often allow humans to come very close and even touch them. While their legs are not well-suited to walking, their strong, webbed toes allow them to perch when not in flight. Aggression, while rare, is usually in the form of bill snapping and jabbing at other birds when competing for perch sights. They do not defend territory beyond their small nest areas. Fledglings' often interact in playful ways. (Berridge, 1934; Diamond and Schreiber, 2002; Peterson and The editors of LIFE, 1963)

Home Range

There is no information available on the home ranges of magnificent frigatebirds.

Magnificent frigatebirds are usually silent, but they do vocalize when approaching a colony, when begging for food (hatchlings), and during mating displays. Little is known about communication among frigatebirds. (Diamond and Schreiber, 2002; Diamond, 1973)

Magnificent frigatebirds eat mainly fish, as well as squid, jellyfish, and crustaceans. However, their diet can greatly vary due to food availability and preferred hunting technique. The three main hunting techniques are dipping, kleptoparasitism, and opportunistic feeding. When dipping, these birds gracefully glide just above the surface of the water and skim the surface with their beak to catch fish. However, they are only able to dip about 15 cm deep to avoid getting their feathers wet. Kleptoparasitism, the stealing of another animal’s food, is how this species gets one of their nicknames, "Man-'o-War". They chase other birds, particularly gulls, gannets, terns, and boobies. This chase continues until the victim is forced to disgorge their food. Magnificent frigatebirds then catch the disgorged food in mid air. They may also catch the other bird by the tail feathers and shake it until they release their food. Opportunistic feeding involves eating garbage, young turtles at hatching, and otherwise taking advantage of all available food sources. Magnificent frigatebirds eat fish scraps discarded by boats, offal (discarded parts of animals unfit for consumption) from slaughterhouses, and other garbage. Occasionally they steal food from the hands of humans. Females consume more than males because of their larger size and greater contribution to the feeding of hatchlings. (Colixto-Albarrán and Orsorno, 2000; Diamond and Schreiber, 2002; Diamond, 1973; Elphick, 2004; Osorno, Torres, and Macias Garcia, 1992; Peterson and The editors of LIFE, 1963)

There are no known birds that prey on magnificent frigatebirds. Mammals may sometimes take eggs and nestlings. However, magnificent frigatebirds closely monitor their eggs and hatchlings until they are fairly able to defend themselves and breeding occurs in colonies, where many eyes can keep watch for predators. (Diamond and Schreiber, 2002)

Magnificent frigatebird feeding habits affect their fish prey, especially flying fish (Exocoetidae), as well as some squid and crustaceans. Other birds like pelicans, gulls, gannets, terns, and boobies are affected by magnificent frigatebird kleptoparasitism. Magnificent frigatebirds are often found near groups of dolphins, tuna, or other predatory fish that drive much of their prey to the surface of the water. This makes magnificent frigatebirds more successful when using a dipping hunting technique. (Heiling, Herberstein, and Chittka, 2003; Osorno, Torres, and Macias Garcia, 1992)

There are no known negative impacts of magnificent frigatebirds on humans.

Magnificent frigatebirds are beautiful and may attract ecotourism. They are also important members of the healthy ecosystems they inhabit.

There are an estimated 50,000 to 71,000 breeding pairs of magnificent frigatebirds. Their numbers are apparently declining, due to human disturbances to nesting areas. There is a need for more research and protection plans in order to ensure that magnificent frigatebird populations remain stable. Regulations have been proposed to the Government of Antigua and Barbuda, but there is no current legal protection for this species. (Diamond and Schreiber, 2002)