The anhinga is a large water bird. It typically measures approximately 29.5 to 37.4 in (75 to 95 cm) in height, and weighs about three lbs (1.35 kg). Often found near rivers, sloughs, marshes, lakes, and similar habitats, it prefers the warm climates found from the southeastern U.S. to the nation of Argentina.
It has a long, pointed bill, which it uses to spear and eat fish. The male is usually dark in color, except for some lighter patches on its wings. Females generally have lighter coloring, particularly on their neck and chest feathers. Unlike many other large fishing birds, the anhinga lacks oil glands to waterproof its feathers. This allows it to quickly dive into water for fish, but it must periodically perch and dry its wings out.
The anhinga’s genus and species is anhinga anhinga. It is also sometimes known as a snakebird. This name comes from the way it swims when its feathers are waterlogged. It is also due to that fact, when it is swimming, the bird's long, thin neck and relatively thin head typically look very much like a water snake. It is also known as a water turkey, because of its broad, long tail. Although its coloring is primarily dark, the anhinga has a greenish iridescence to its dark feathers.
Other than fish, the anhinga has been known to eat baby alligators. It also consumes crayfish, insects, and frog eggs, among other creatures. When the anhinga spears fish with its pointed bill, it sometimes spears them so hard that it is necessary for it to swim to shore to remove the fish from its bill before eating it.
Anhingas are often confused with cormorants, but many differences exist between the two water birds. Cormorants have a flatter, less pointed, and yellower bill. They also do not have light coloring present on their wings, as the anhinga does. Cormorants can also live in colder habitats, and migrate in the winter to warmer areas. Also, anhingas have longer tails and necks, and flap their wings and soar while in flight, while cormorants generally only flap and do not soar while flying.
Anhingas mate monogamously. The male starts a potential nest site, and soars during courtship. The birds may build their own nest, or use one that belonged to a heron or egret. In fact, anhingas often nest among groups of herons and egrets. Female anhingas usually lay about four eggs, which hatch after a 29-day incubation period. Although dependent on their parents for some time, hatchlings can swim away from danger if necessary.