Eudocimus albus

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American Ibis - Eudocimus albus

American Ibis foraging in shallow water

Characteristics The American White Ibis about 2 feet tall and has a wingspan of about 3 feet. It is entirely white, except for its black-edged wings. Its blacked tipped wings may not be noticeable when the ibis is at rest, but they are easily seen when the ibis is in flight. It has a long, down-curved, reddish-orange bill and a reddish-orange face. It legs are long and gray, except for during breeding season when they turn reddish-orange. Young white ibis are brown on their uppersides and white on their undersides and they have brown bills and legs[1]. The American White Ibis is part of the spoonbill family that are large long-legged wading birds and members of the family have long, broad wings with 11 primary feathers and about 20 secondaries. They are strong fliers and, rather surprisingly, given their size and weight, very capable soarers. The body tends to be elongated, the neck more so, with rather long legs. With long red legs, all white plumage, red face, and long decurved red bill, an adult White Ibis in breeding plumage is easily identified. Black wing tips are especially evident in flight. In flight, the outstretched wings measure three feet across, and have small yet obvious patches of black at the tips. Adults stand about two feet tall, and weigh about two pounds. Juvenile birds are dark overall. They become increasingly pale over the first year or so, molting into white adult plumage by early in their second year. The bill, face, and legs of young birds change similarly, from dark, to orange, to the red of adulthood[2].

    BIOMETRICS:
  • Length: 64 cm
  • Wingspan: 97 cm
  • Weight: 750-1050 g

    LONGEVITY:
  • Up to 20 years[3]


Classification

  • Phylum: Chordata
  • Class: Aves
  • Order: Ciconiiformes
  • Family: Threskionithidae
  • Genus: Eudocimus[4]

Range The white ibis can be found on the Atlantic Coast from Virginia south to Florida and along the Gulf Coast west to Texas. It is also found in Mexico and Central America[5]. In North America, the White Ibis breeds coastally from Louisiana east along the Gulf Coast. They occur inland across Florida, and along the Atlantic coast as far north as the Carolinas. The non-breeding range extends further inland, north to Virginia, and west to eastern Texas. The White Ibis is known to wander, and has been recorded, albeit rarely, in states far out of range, sometimes in small flocks. The species is most common in Florida, where over 30,000 have been counted in a single breeding colony. The species also occurs throughout the Caribbean, on both coasts of Mexico and Central America, and as far south as Columbia and Venezuela[6].

Habitat The white ibis lives in a variety of coastal freshwater, saltwater and brackish marshes, rice fields, mudflats, mangrove swamps and lagoons[7]. Shallow coastal marshes, wetlands, and mangrove swamps are the White Ibis's preferred habitat. Populations away from the coast make use of marshes, ponds, flooded fields and a variety of other wet habitats, particularly in southern Florida. The White Ibis feeds in fresh, brackish, or salty water[8].

Diet A highly social species, the White Ibis often feeds in large flocks. The birds wade slowly through shallow water, heads down, probing the bottom by sweeping their long bills back and forth across the bottom. They often capture food by sense of touch alone. The species also forages on land. Crabs, crayfish, and other crustaceans are the preferred prey, but the diet is diverse. The White Ibis also eats insects, fish, frogs and a wide variety of aquatic animals[9].The white ibis wades in the water sweepings its head form side-to-side in search of food. It uses its long, curved bill to probe in the mud for crabs and crayfish. It swallows its prey whole. It also forages for food on land, and it may also eat insects, frogs, snails, marine worms, snakes, and small fish. Flocks of white ibis will move to different locations in search of food. Other wading birds often follow behind the white ibis and catch prey that has been disturbed by the probing ibis[10].

Life Cycle The white ibis breeds in large colonies that may include other wading birds. Males arrive at the breeding grounds first. Pairs form in spring, and nesting begins as soon as suitable foraging habitat is available. The female chooses the site and builds the nest, usually in the branches of a tree or shrub. The male assists by bringing her nesting material, occasionally stolen from a neighbor. During incubation, the male aggressively defends his nest and mate from both predators and other ibises. Eggs hatch after about three weeks, and the chicks are weak and helpless for the first several days. The young are attended constantly for the first two weeks, then left on their own for short periods. Young White Ibis are susceptible to salt stress, so the availability of a freshwater food source is essential for young to develop normally. Upon leaving the nest, juvenile birds form flocks with other juveniles[11].The male preens and points its bill towards the sky to attract a mate. Both the male and female build the nest. The male brings sticks, reeds, leaves and other plant materials to the female who then constructs a platform nest in the crotch of a tree, in a shrub or sometimes on the ground. The female lays 2-5 eggs, and both the male and the female incubate them. The eggs hatch in about 21 days. Both parents feed the chicks regurgitated food. The chicks fledge when they are about six weeks old[12].The white ibis nests and feeds in large groups. Nesting colonies may include thousands of birds. The white ibis will fly up to 15 miles a day in search of food[13].

Migration Short seasonal migrations occur in certain parts of the species' range. In general, there is a push toward coastal areas in winter. The species is nomadic, so large flocks may wander outside the breeding season, often in search of new food sources[14].


References

http://www.nhptv.org/natureworks/whiteibis.htm

http://birds.audubon.org/species/whiibi