Frigatebirds (FRIGG-it-birdz) are unusual seabirds. Their feathers are not waterproof, so they try to avoid getting them wet. They have mostly dark feathers, although many frigatebirds, especially the females and young ones, have white feathers on their breasts, and some young birds have white heads. The birds also have short legs, webbed feet, forked tails, and the males have an inflatable pouch on their throats.
Frigatebirds have extremely long, pointed wings. In fact, they have the largest wings in proportion to their weight of any other bird. They also have exceptionally strong breast muscles that work together with their wings to make them powerful, acrobatic fliers.
Female frigatebirds are somewhat larger than the males. The birds are between 30 and 44 inches (75 and 112 centimeters) long from their bills to the end of their tails, and their wingspan is between 69 and 91 inches (176 and 230 centimeters). They weigh up to 3.3 pounds (1.5 kilograms), and almost half of their body weight consists of breast muscles and feathers.
Magnificent frigatebirds fly above the warm ocean water and breed on tropical and subtropical islands all around the world. The other four species of frigatebirds are more rare, and each species breeds on only a few remote islands.
Frigatebirds breed in colonies with other frigatebird on tropical islands. The warm water near their islands is about 77°F (25°C). They choose islands that are near water with plenty of flying fish, fish that jump and glide in the air before falling back into the water.
Flying fish are the main diet of frigatebirds. They also snatch fish and other animals at the sea’s surface. They attack other seabirds in the air and steal their prey. Frigatebirds sometimes eat the eggs and young of other seabirds, as well as fish scraps thrown overboard by fishing boats.
BEHAVIOR AND REPRODUCTION
During the day, frigatebirds spend moat of their time in the air. They usually search for food around their home islands, but they sometimes fly far out over the ocean when they are not breeding. They may breed at any time of year. Male birds sit at a nest site and blow up their throat pouches to attract females. They prefer to build their nests in low shrubs or trees, but sometimes they put them on the bare ground. They lay just one egg, and the young bird learns to fly between the age of five and seven months. After that, it is still dependent on its parents for food for another two to six months.
FRIGATEBIRDS AND PEOPLE
People have used to use frigatebirds to carry messages between islands in the South Pacific. Now the birds are mainly a tourist attraction.
The Ascension frigatebird is listed as Critically Endangered, facing an extremely high risk of extinction, and the Christmas frigatebird is considered Vulnerable, facing a high risk of extinction. Both lost much of their habitat when people developed the islands where they breed, and they do not like to be disturbed by people who come to watch and photograph them close-up. But their biggest trouble is the variety of mammals brought to the islands by people. Rats, pigs, goats, and pet cats eat the frigatebirds’ eggs and chicks, and they destroy the plants the birds need in breeding areas.