Gannets are true sea birds, but, as a rule, do not live very far from the land. When breeding, Gannets are usually associated in great numbers. Their nests, as a rule, are placed on the ground or on cliffs, and one or two chalky white eggs are laid. At this season the birds are exceedingly tame and in localities where they have not been much molested, one may walk about among the sitting birds without their taking flight. Gannets are powerful birds on the wing. Their vigorous wing strokes are interrupted at intervals by short sails. They feed on fish which they capture by diving from the air.
The Darters or Anhingas number four species, distributed throughout the tropical parts of the globe, only one species inhabiting America. This is generally called the Snakebird or Water Turkey in Florida, where it is a common species on the more isolated rivers and lakes. The name Snakebird is derived from the bird's habit of swimming with the body submerged, when the long, sinuous neck, appearing above the water, readily suggests a snake. At other times Snakebirds mount high in the air and sail about, like Hawks, in wide circles. They build a large, well-made nest in a bush or tree, generally over the water, and lay four bluish white, chalky eggs.
Cormorants nest in large colonies, generally on isolated islets, but sometimes in remote swamps. The nests are placed closely together on the ground, in bushes, and less frequently in trees, according to the nature of the bird's haunts.
Cormorants feed on fish which they catch by pursuing them under the water. They dive from the surface of the water like Ducks, or from a low perch, but not from the air, as do the Gannets.
Pelicans nest in colonies, generally on some small island, building their nests on the ground or in bushes, and laying two or three large, white, chalky eggs.
Brown Pelicans secure their food by plunging on it from the air, generally from about twenty feet above the water. The sides of the bill are then bowed outward, the opening widened, forming, with the pouch, an effective net in which fish, twelve and fourteen inches long, are captured.
White Pelicans, on the contrary, feed from the water, scooping up fishes as they swim. At times a flock of these birds may surround a school of small fish in shallow water and drive them shoreward, at the same time actively filling their pouches.
Young Pelicans are fed on fish which they take from the pouch of the parent bird by thrusting their bills and heads well into it and prodding actively about for the food to be found there. Young Cormorants secure their food in a similar manner.
Frigate Birds, of which only two species are known, have a greater expanse of wing in proportion to the weight of their body than any other bird. Their power of flight is consequently unexcelled and they may spend days in the air without tiring. Their feet are as weak as their wings are strong, and are of use only in perching.
The food of Frigate Birds consists chiefly of fish, which they catch from near the surface of the water, or rob from Gulls and Terns by pursuing them, forcing them to disgorge their prey, and catching it ere it reaches the water.