White ibis (Eudocimus albus)
|Also known as:||American white ibis|
|Size||Length: 56 - 68 cm (2)|
|Weight||750 - 1,050 g (2)|
The white ibis is classified as Least Concern (LC) on the IUCN Red List (1).
With its distinctive brilliant white plumage and contrasting black primary feathers, the white ibis (Eudocimus albus) is a striking, unmistakable wading bird. This curious species may also be recognised during the breeding season by its bright pink face, bill and legs. At other times of the year these body parts are all pale orange. The juvenile white ibis is mostly brown, but has white underparts, dark legs, and a pink bill with dusky bands (2) (3).
The white ibis has partially webbed feet, which helps it balance whilst walking on muddy ground. Its long, curved bill is highly sensitive to movement and allows the white ibis to find prey submerged in water or burrowed into soft mud (2) (3).
Occurring as far north as Canada, the white ibis ranges southwards through the United States, Central America, and into the northern countries of South America. It is also found on some of the Caribbean islands, including the Cayman Islands (2) (3) (4) (5).
The white ibis occupies a variety of inland and coastal habitats, including forests, tropical mangroves, and wetlands, such as salt marshes and swamps (2) (4).
Whilst foraging in shallow, sparsely vegetated water, the white ibis uses the long, sensitive bill to search for its prey by touch rather than by sight. It moves through the water slowly, periodically stopping to probe its bill under vegetation or down a crustacean burrow. It feeds on a variety of crustaceans, insects, amphibians, small snakes and small fish, and picks its prey up in the forceps-like bill, before breaking larger items up or swallowing the smaller items whole (2).
The timing of breeding varies across the white ibis’ range, as it is heavily influenced by changes in prey abundance. However, in southern Florida, breeding typically occurs during the heavy rains of June and July. The male white ibis arrives at the breeding grounds first, and soon begins displaying to spectating females, which arrive after the male. Once a pair bond is established, a nest site is chosen on the forking branch of a tree or bush. The female builds the nest, weaving dead twigs collected by the male together with vegetation. Up to four eggs are laid over a period of a week, and the pair then continually incubate the clutch for approximately 21 days. The hatchlings are cared for constantly as they are weak and prone to overheating, and they are fed on freshwater prey such as small fish. The hatchlings leave the nest after two weeks, and in some regions may leave the colonies as early as 40 days after hatching (2).
While the global population of the white ibis is currently thought to be fairly stable, this species is highly vulnerable to human disturbance when nesting. Such disturbance can cause breeding pairs to temporarily desert their nests, leaving the eggs or chicks open to predation and exposure. The white ibis’ breeding success is also affected by the build up of toxic pollutants within the environment, as these contaminants enter its body through its prey and can lead to thinner egg shells being produced. In addition, the white ibis has been hunted for food and may be shot as vermin, due to it being perceived as a threat to the shellfish industry (2).
There are currently no known conservation measures targeting the white ibis. However, this species will benefit from plans to restore the wetlands of the Florida Everglades, which will increase the number of potential foraging and nesting sites (2). Other conservation recommendations for the white ibis include the protection and management of additional foraging and nesting sites, although this may prove difficult to implement as this species often moves between different sites each year (2).
For more information on the white ibis and other bird species:
For more information on the Cayman Islands National Trust:
Cayman Islands National Trust:
- Crustaceans: diverse group of animals with jointed limbs and a hard chitinous exoskeleton characterised by the possession of two pairs of antennae, one pair of mandibles (mouthparts used for handling and processing food) and two pairs of maxillae (appendages used in eating, which are located behind the mandibles). Includes crabs, lobsters, shrimps and barnacles.
- Incubate: to keep eggs warm so that development is possible.
- Primary feathers: in birds, the main flight feathers projecting along the outer edge of the wing.
IUCN Red List (October, 2010)
Heath, J.A., Frederick, P., Kushlan, J.A. and Bildstein, K.L. (2009) White Ibis (Eudocimus albus). In: Poole, A. (Ed.) The Birds of North America Online. Cornell Lab of Ornithology, Ithaca. Available at:
- Ridgely, R.S. and Gwynne, J.A.Jr. (1989) A Guide to the Birds of Panama: With Costa Rica, Nicaragua, and Honduras. Princeton University Press, New Jersey, USA.
- Rappole, J.H. and Blacklock, G.W. (1994) Birds of Texas: A Field Guide. Texas A&M University Press, Texas, USA.
BirdLife International (October, 2010)