Anhinga

                         Anhinga - Wężówka amerykańska

Brazil, Pantanal, 2013

Description

The Anhinga sometimes called Snakebird, Darter, is a water bird of the warmer parts of the Americas. The word anhinga comes from the Brazilian Tupi language and means devil bird or snake bird. It is a cormorant-like bird with an average body length of 33 in, a wingspan of 46 in, and a mass of up to 3.0 lb. It is a dark-plumaged piscivore with a very long neck, and often swims with only the neck above water. When swimming in this style the name Snakebird is apparent, since only the colored neck appears above water the bird looks like a snake ready to strike. They do not have external nares (nostrils) and breathe solely through their epiglottis. The female Anhinga is similar to the male Anhinga except that it has a pale gray-buff or light brown head, neck, and upper chest. The lower chest or breast is a chestnut color and as compared to the male, the female has a more brown back.

Habitat

The Anhinga lives in shallow, slow-moving, sheltered waters and uses nearby perches and banks for drying and sunning. It's rarely found out of freshwater except during severe droughts. Generally not found in extensive areas of open water, though it may nest on edges of open bays and lakes. Breeds near freshwater, often in association with other water birds such as herons, egrets, ibises, storks, and cormorants. The Anhinga may also breed in saltwater colonies and feed in fresh water. Only birds that do not live in the extreme north and south of their range migrate and do so based on temperature and available sunlight. Anhinga will migrate towards the equator during winter but this range is "determined by the amount of sunshine to warm the chilled birds". Although not in their usual range, anhinga have been found as far north as the states of Pennsylvania in the United States.

Voice

Sounds of Anhinga

Diet

The Anhinga dives from the surface of the water and swims slowly underwater stalking fish around submerged vegetation. The diet consists of many small to medium-sized wetland fishes, with very small amounts of crustaceans and invertebrates. Anhinga typically spear fish through their sides with a rapid thrust of their partially opened bill. Usually stabs with both mandibles, but may use upper mandible only on small fish. The side-spearing habit of the Anhinga suggests that the usual hunting method is by stalking rather than pursuit.

Reproduction

The male begins nest construction before it has a mate, by placing large sticks and green material in the forks of trees. The male collects nearly all nesting the material, and the female then finishes building nest. The nest is a bulky platform of sticks, somewhat more compact than heron nests. It is often lined with fresh leaves, green twigs, willow leaves, and catkins. With age, excrement can build up on the outer rim of the nest giving it a white appearance. 
   The hatchling starts out bald but gains tan down within a few days of hatching. Within two weeks the tan down has been replaced by white down. Three weeks after hatching, the first juvenile feathers appear. Juveniles are mostly brown until first breeding after the second or third winter.


DID YOU KNOW? Unlike ducks, the Anhinga is not able to waterproof its feathers using oil produced by the uropygial gland. Consequently, feathers can become waterlogged, making the bird barely buoyant. However, this allows it to dive easily and search for underwater prey, such as fish and amphibians. It can stay down for significant periods.

 
 

Photos by others

Credits

Wikipedia, Cornell Lab of Ornithology