Magnificent Frigatebird
Magnificent Frigatebird

Common name: Magnificent Frigatebird, Man O’War
Scientific name: Fregata magnificens
Length: 100 to 230 cm, wingspan of up to 2.5 m
Weight: 1,360 to 1,815 g (3 to 4 lb)
Population: approximately 60,000
Distribution: along tropical and subtropical coasts of the Americas, on islands, shorelines and in mangroves
Issue: disturbance by humans
IUCN Red List status: least concern

A large frigatebird with long, sleek wings, this seabird feeds on fish, turtles, squid, jellyfish, and crustaceans. Males are all black with a bright red “gular sac,” a membranous elastic pouch below their long, hooked beak that they can inflate to attract females during the breeding season. Females are black with a white breast and white wing patches and are are 15 percent larger than males on average. They have forked tails, and their small feet are poorly adapted to walking or swimming.

During the breeding season, males gather in groups to display in front of females. They inflate their gular sacs until it hides their head and tilts it backwards, make piercing calls, flutter their wings, and sit back on their tails to show off their finery to females. The purpose of this courtship display is to ensure that the males with the best calls and the most attractive plumage and gular sacs—evidence of their strength and genetic superiority—have the best reproductive success. Once couples form, they produce a single egg. Although males mate every year, females only mate every other year because they spend more time caring for the young. Individuals form new pairs every year.

Because the Magnificent Frigatebird’s plumage is not waterproof, it cannot land on or dive into the water to catch fish or it will drown. So it can only capture prey that is less than 15 cm from the water’s surface. This does not mean that it is not a formidable predator, however. In constant flight, it harasses other birds and forces them to disgorge their meals, a feeding strategy called “kleptoparasitism.” The Magnificent Frigatebird will chase Northern Gannets, terns and gulls, occasionally catching them by the tail feathers and shaking them until they give up their prey. They are also opportunists, feeding on any type of available food, such as garbage, bycatch fish and fish offal thrown overboard by fishing boats. They also eat baby turtles, which, having hatched out of eggs buried in the sand, struggle as best they can down the beach to the water and relative safety. If ever you find yourself in its range, the Magnificent Frigatebird has even been known to snatch the food right out of people’s mouths. Females eat more than males in order to feed their chicks.

The species nests in trees or in dense vegetation on islands and shorelines in its breeding areas. Some colonies, such as the one on Barbuda in the Caribbean, contain up to 2,500 breeding pairs. The oldest known Magnificent Frigatebird was 34 years old.

The Magnificent Frigatebird is classified by the International Union for Conservation of Nature as being of least concern. Its range is huge, which benefits the species. However, like most bird species, its numbers appear to be slowly declining, likely because of the numerous disturbances to natural habitats caused by humans. While no well-defined threat to the Magnificent Frigatebird has been identified, it is probable that overfishing has reduced its sources of food.

Did you know?
The Magnificent Frigatebird is one of the few birds to spend most of its life in flight (with the exception of the breeding season). To be able to do this without tiring, it rides currents of warm air to altitudes of up to 2,500 metres and then glides down. This constant up-and-down movement allows it to conserve energy as it travels. The range of this curious species can therefore be partially explained by the presence of “trade winds,” the ascending and descending prevailing winds that blow in the tropics.

REFERENCES: Red List of Threatened Species of the International Union for Conservation of Nature (IUCN) and Encyclopedia of Life.

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