American White Ibis

The American white ibis (Eudocimus albus) is a striking wader of the ibis family, Threskiornithidae. It is a medium-sized bird with a predominantly white plumage, which contrasts with its bright red-orange down-curved bill and long legs. The tips of its wings are black, a detail most apparent when the bird is in flight. Sexual dimorphism is present, with males being larger and possessing longer bills than females.

Identification Tips

Adult American white ibises have distinctive pink facial skin and black wingtips visible in flight. In non-breeding condition, their bill and legs are a vivid red-orange. During breeding, the bill darkens at the tip and the legs take on a purple hue. Juveniles are brown and white, with the white becoming more prevalent as they mature. The species is relatively short-legged and bulky for its size, with a wingspan ranging from 90 to 105 cm.

Habitat

The American white ibis frequents a variety of wetland habitats, including shallow coastal marshes, mangrove swamps, and inland wetlands such as marshes, ponds, and flooded fields. It adapts well to both natural and man-made water bodies.

Distribution

This ibis is found from Virginia through the Gulf Coast of the United States, extending south through the coastal New World tropics. Its breeding range includes the Gulf and Atlantic Coasts, as well as the coasts of Mexico and Central America. The non-breeding range extends further inland and includes the Caribbean and parts of South America.

Behaviour

The American white ibis is a sociable bird, often seen in large flocks. It is territorial during the breeding season, with pairs forming monogamous bonds. Males may engage in extra-pair copulation to increase reproductive success. The species is known for its undulating flight pattern and honking calls.

Song & Calls

The primary call is a honking sound, used in various contexts such as flight and courtship. Additional vocalizations include a muted foraging call and a high-pitched begging call from young in the nest.

Breeding

Breeding occurs in large colonies near water, with both parents caring for the young. Nesting begins with the availability of suitable habitat, and the female is responsible for nest construction. Clutch sizes vary, with crayfish being the preferred food for chicks.

Similar Species

The American white ibis can be confused with the glossy ibis or the wood stork, but can be distinguished by its white plumage and red-orange bill and legs. Juveniles may be mistaken for the scarlet ibis, but the latter has darker legs.

Diet and Feeding

The diet primarily consists of small aquatic prey, with crayfish being favored. The ibis probes shallow waters with its beak to locate and capture prey, which it does not visually see. Diet varies with habitat and prey availability.

Conservation status

The American white ibis is classified as Least Concern by the IUCN. Populations are stable, though they can fluctuate and move between states. Conservation efforts focus on preserving wetland habitats and monitoring environmental impacts such as pollution.