BOOBIES AND GANNETS – Sulidae

BOOBIES AND GANNETS

BOOBIES AND GANNETS FACTS

Boobies and gannets are large seabirds with long, pointed wings, cone-shaped bills, forward-facing eyes, and long necks and tails. Their length is between 25 and 39 inches (64 to 100 centimeters) from their bills to the end of their tails. They are strong fliers and plunge divers—boobies and gannets hit the water headfirst from high in the air in search of fish, and have air sacs under the skin that cushion them when they hit the water.

GEOGRAPHIC RANGE

Boobies and gannets are spread widely over the oceans of the world. Boobies are found mostly in warm tropical or subtropical waters, while gannets usually live in more temperate, cooler regions.

BOOBIES AND GANNETS HABITAT

Gannets and boobies live mostly at sea and nest on offshore islands. They usually place their nests on flat ground or on the sides of cliffs. On tropical islands, some also build nests in trees or bushes.

BOOBIES AND GANNETS DIET

Boobies and gannets feed mostly on schools of fish in ocean waters. Boobies also catch flying fish and squid. They plunge into the water, and they often swallow their prey before swimming back to the surface. By swallowing the fish underwater, they avoid being pestered by gulls and frigatebirds that might try to steal their catch.

BEHAVIOR AND REPRODUCTION

These birds are very sociable and nest close together in large colonies. They have developed a lot of different courtship and pairbonding displays that the pairs use to say that they belong to each other. The birds hardly ever fight, even though they are so near to each other. Instead, they have displays that tell close-by birds to keep their distance.

Almost all of these birds lay their eggs right on the ground. The two booby species that use trees and bushes build stick nests. Most of these birds lay only one egg. A few lay two or three, but sometimes only one survives. The parents take turns keeping the eggs warm by wrapping their webbed feet around them, and both of them care for the chicks until they are on their own.

BOOBIES, GANNETS, AND PEOPLE

Over the centuries, boobies and gannets and their eggs have been an important source of food for people when the birds were nesting. Some of the birds’ droppings were collected and used for fertilizer on farms, often disturbing the birds on their nests. People still eat the birds on some tropical islands, and birdwatchers enjoy them worldwide.

CONSERVATION STATUS

Abbott’s booby is listed as Critically Endangered, facing an extremely high risk of extinction, dying out. It lives only on Christmas Island, where it lost much of its habitat when nesting trees were cleared. The cape gannet is listed as Vulnerable, facing a high risk of extinction, because it has only six breeding colonies. The other gannets and boobies are not in danger of extinction, but many would be better off if their island habitats were protected.