It is not really known exactly why boobies were given that name by sailors who first saw them and may have visited their nesting colonies on tropical islands. The sailors may have thought that the birds were “boobies” because they were so trusting. Since boobies nest, for the most part, on small uninhabited islands, they were unacquainted with men and permitted the sailors to approach without showing any signs of the fear that wild animals normally show at the approach of men.
Regardless of the reason, the six species of gannets living in tropical waters have retained the common name of booby.
Boobies are relatively large sea birds. They are white and black or white and brown, depending on the species. The colourful parts of their bodies are those covered by naked skin rather than feathers. For instance there are the blue-footed boobies, the blue-faced boobies, and the red-footed boobies. But these colours may change between the breeding and the non-breeding seasons.
Most boobies tend to nest in colonies. It is thought that those living below the equator nest between October and April, although being tropical birds, they may also have no definite nesting season. The adult males usually arrive at the future nesting sites first and pick a territory. The females soon follow, and each accepts a particular male as her mate. Most boobies mate for life and the pair bond is strong.
Boobies generally nest on the ground, although a few species build crude nests in trees. A common display among them is for the male to offer the female a twig or pebble for the nest. Other ceremonies may include mutual neck preening and an uptilting of heads. Their cries on the nesting grounds are described as trumpeting and whistling. Most boobies raise only one young each season, although they may lay two or more eggs. Both the female and the male incubate the eggs and care for the young birds. The young booby is almost nude when it first comes out of the egg, but within a short time it is covered with white down. Both parents feed their offspring, at first with regurgitated food and later with small, whole fish.
During the first days of its life the young booby is’ shielded from the hot, tropical sun by its brooding parents. Later, however, the parents leave it for ever-increasing periods of time. Soon the young bird loses its down, and in about four to six months its first plumage of mottled brown and white feathers comes in. At last it is ready to take off to sea and fish for itself.
The young boobies wander far from their nesting sites and may travel thousands of miles. During each moult their feathers become closer to the colours of the adult plumage. Finally, after from three to five years they return to their ancestral grounds to mate.
Boobies are expert fishers. They fly above the water until they sight a fish. Then with wings closed or half-closed, they dive often from heights of fifty feet or more. They can swim underwater, using both their wings and feet. They eat the fish underwater, rather than returning to shore with it. Boobies tend to feed in small flocks in the early morning and in the late afternoon. During bright moonlit nights they may fly all night. They are often harassed by frigatebirds which make them regurgitate the fish they have been lucky enough to catch.
Boobies Pictures
