Frigatebirds: Fregatidae

Physical characteristics: Magnificent frigatebirds are the largest of the frigatebirds, with a length of 41 to 44 inches (104 to 112 centimeters) from bill to tail, and they weigh between 3.1 and 3.3 pounds (1.4 and 1.5 kilograms). Their straight gray bills are hooked at the end. They have such short legs that they cannot walk on land or swim on the water, but their strong claws help them cling to the branches where they roost and build their nests. The adult female has a white breast and some brown feathers on the top of her wings. The adult male has a mostly black body with a red throat sac.

No other birds in the world have wings as large in proportion to their weight as magnificent frigatebirds. Their wingspan is 85 to 91 inches (216 to 231 centimeters). The birds' strong breast muscles work together with their wings, making them able to fly fast and soar high, and their forked tails help them steer.

Geographic range: Magnificent frigatebirds breed on tropical and subtropical islands in the Atlantic and Pacific Oceans near North and Magnificent frigatebirds prefer to live on tropical islands with trees and bushes for nesting surrounded by an ocean full of flying fish. (Illustration by Patricia Ferrer. Reproduced by permission.) South America. Some also breed in mangrove trees along the coasts. Colonies of the birds are also found off the western coast of Africa. They usually roam the waters near their home islands, but they sometimes fly far out over the ocean.

Habitat: The ideal habitat for a colony of magnificent frigatebirds is a tropical island with mangroves or other trees and bushes for nesting surrounded by an ocean full of flying fish.

Diet: Magnificent frigatebirds feed on flying fish that they catch in the air up to 6 or more feet (1.8 or more meters) above the surface of the ocean. They also eat other small fish, as well as squid, young turtles, crabs, and jellyfish. Frigatebirds snatch this prey from the surface of the water. They like the eggs and chicks of other seabirds when they can get them, and they eat the fish parts discarded by fishing boats. Sometimes they steal the prey of other seabirds in midair.

Behavior and reproduction: Magnificent frigatebirds never land on water, except accidentally. Their feathers are not waterproof and quickly become wet and heavy in the water, making it difficult for them to take off. Instead, they spend their daytime hours in the air, and they perch in bushes or on tree braches when they roost each night. They are exceptionally skillful at catching fish and other sea animals while flying right above the surface of the water. Strong winds do not bother them—they can even ride out a hurricane in flight.

At breeding time, the males gather in trees or bushes about pecking distance from each other. It takes the males about twenty-five minutes to blow up their red "balloons." They do it by sucking air into the wrinkled red pouches on their throats. Then they shake their wings and rattle their bills. The females fly overhead and check them out. Then, each one chooses a male as her mate. The pairs build their flat nests of twigs, sticks, and grasses right on the spots where the males were showing off. The males often steal nest material from each other or from other seabirds nesting nearby. The birds are noisy at the nest site, although they are quiet at sea.

Each female lays just one egg, and she will take care of this young bird for more than a year. For about two months, the parents take turns sitting on the egg. The young bird is naked and helpless when it hatches. But soon the chick starts begging loudly to be fed, and it eats food that the parents regurgitate (re-GER-jih-tate; spit up). Before the chick is three months old, its father leaves. After that, the female continues to feed the young bird long after it learns to fly. Young frigatebirds practice catching food on the wing by dropping feathers and seaweed. It takes them a long time to learn how to feed themselves. Females breed every other year, and young birds are ready to breed by the age of seven.

Magnificent frigatebirds and people: These birds have become a favorite of bird-watching tourists, and the money the tourists spend on boat tours, hotels, and food helps the local people who live near the birds.

Conservation status: Magnificent frigatebirds have suffered from loss of habitat at many of their breeding places. Fishing boats have over-fished some of the ocean areas where the birds used to find their food. However, the birds are not in danger of extinction (dying out). ∎