Greater Ani | Crotophaga major

Voice

Noisy. Groups produce a bubbling and cackling chorus reminiscent of turkeys gobbling, including a repeated, hollow kro-koro. Also growling, hissing and whirring sounds, and a harsh alarm when a group is disturbed. The calls carry far over water and often give a group away before the birds themselves are seen.

Identification

45–48 cm, about half of it tail; the male averages slightly larger and heavier than the female. The plumage is entirely black with a strong blue to blue-green gloss on head, breast and wings; the mantle feathers have bronze-green edges, which give the back a scaly look in good light. The iris of adults is white to yellowish white, dark in young birds. The bill is black, very deep and laterally compressed, with a high ridge on the upper mandible that runs up onto the forehead. The tail is long, broad and rounded and is often spread or cocked. The flight is heavy, a few flaps alternating with glides, usually low over the water from bush to bush. The sexes are alike in colour.

Confusion species

Smooth-billed Ani Crotophaga ani is clearly smaller, lacks the blue gloss, has a dark eye and a smooth, high-humped bill; it lives in open, drier country and is much commoner in Trinidad. The male Giant Cowbird Molothrus oryzivorus is also glossy black, but has a pointed, conical bill, a much shorter tail and a ruff of erectile neck feathers. Carib Grackle Quiscalus lugubris also has a pale eye, but is much smaller, with a thin, pointed bill and a V-shaped tail.

Habitat

Mangroves, swamp forest, the banks of rivers, creeks and canals, and other dense scrub and woodland close to water in the lowlands. Groups forage in the vegetation and on the ground at the water's edge, taking large insects such as grasshoppers, as well as other invertebrates, small lizards and frogs and some fruit. After feeding in wet vegetation the birds often sit with wings spread to dry in the sun. The nest is a deep cup of twigs lined with leaves, usually two to five metres up in a tree or bush near water. Two to five pairs share a single nest; several females lay their blue eggs in it and all group members help to incubate and feed.

Range and movements

In the region resident only in Trinidad, mainly in the mangroves and swamps of the lowlands, including the Caroni and Nariva swamps, and along rivers and canals inland. It is absent from Tobago. There are also reports from Aruba, Curaçao and Bonaire, but no established population has been described there, and for Curaçao the species is treated as unconfirmed on the South American reference list. Outside the region in the tropical lowlands of South America, from Panama, Colombia and Venezuela through the Guianas and the Amazon basin to northern Argentina.

• Resident
• dark = core range, pale = thinly spread

How and when to look

A boat trip through the Caroni Swamp or a visit to the edge of the Nariva Swamp gives the best chance; groups sit in the mangroves along the creeks and are usually first noticed by their bubbling calls. On sunny mornings they often perch with wings spread on an open branch, when the pale eye can be seen at close range.

Conservation status

Not threatened. The species has a very large range in South America. In Trinidad it depends on the mangroves and swamps of the lowlands; the protection of areas such as Caroni and Nariva matters for the population there.

Scientific name

Crotophaga major | Gmelin, 1788

Gmelin described the species in 1788 and placed it straight away in the genus where it still stands. The genus Crotophaga was introduced in 1758 by Linnaeus. Crotophaga is Greek, from krotōn 'tick' and -phagos '-eating': 'tick-eater', as anis were thought to feed on ticks. major is Latin for 'greater', as it is the largest ani. The specimen the first description was based on came from Cayenne, French Guiana.