Grey-necked wood rail (Aramides cajaneus)

Jan 21, 2018 Features / Columnists, Interesting Creatures in Guyana

The grey-necked wood rail or grey-cowled wood rail (Aramides cajaneus) is a species of bird in the family Rallidae, the rails. It lives primarily in the forests, mangroves, and swamps of Central and South America.
Of the two subspecies, A. c. avicenniae is found in southeastern Brazil, while the nominate is found throughout the portion of the range not occupied by the other subspecies.
The species as a whole is usually found at elevations from sea level to 2,000 metres (6,600 ft), although some have been found above that. This bird’s large extent of occurrence along with its population is why it is considered to be least-concern by the International Union for Conservation of Nature (IUCN). In some places, it is occasionally hunted and kept for food.
This bird, large for a wood rail, has both a grey head and, as the name implies, neck. In the nominate, the back of the head has a brown patch. The upperparts are olive-green to dark brown. The chest and flanks are a rufous colour, with the belly, rump, and tail being black. The legs are coral-red, the bill is a bright greenish-yellow, and the eyes are red.
The sexes are similar. The juveniles can be differentiated by their duller look, and the chicks have a black, downy appearance, brown head, and black beak. The subspecies avicenniae can be differentiated by its smaller size, lack of a brown patch at the back of the neck, and its lower back being toned slightly olive. The underparts are also pale.
A monogamous bird, pairs can be found together throughout the year. During the breeding season that usually lasts from March to August, the grey-necked wood rail builds nests that can be found on flat branches and in thickets, usually at heights between one and three metres (three and 10 ft). In these nests, there is a clutch consisting of three to seven eggs, incubated by both sexes. The chicks that hatch are precocial, able to move soon after hatching. This rail feeds on a wide range of foods, from molluscs to seeds. It is also known to feed on the feces of giant otters.
The grey-necked wood rail is regarded as being sister species with the rufous-naped wood rail, one of the nine members of the genus Aramides, of which the grey-necked wood rail is included.
The grey-necked wood rail usually measures 33–40 centimetres (13–16 in) long and weighs 320–465 grams (11.3–16.4 oz), particularly large for a wood rail. Juvenile birds are similar to the adult but are duller in colour, with their belly sooty-black and flecked with buff. The juveniles also differ in the fact that their bill and legs are dusky, and have brownish eyes. The chicks are black and downy, with a brownish head. Their dark eyes are lined with dull, reddish bare skin. The black bill has a flesh-coloured base, and a small, white egg tooth behind the tip of the upper mandible, as well as a very small one at the tip of the lower mandible.
This bird moults its remiges simultaneously. This moult occurs during the months from March to June.
The grey-necked wood rail has a loud, repetitive cackling call mainly heard at dawn and dusk: pop-tiyi pop-tiyi co-co-co-co-co or chitico chitico cao-cao-cao. These songs are often sung in a chorus or duet. The alarm call is a harsh, loud cackle or clucking shriek. The chitico chitico cao-cao-cao call made by this rail is similar to the brown wood rail’s kui-ko call.
The grey-necked wood rail is found in Argentina, Bolivia, Brazil, Colombia, Costa Rica, Ecuador, French Guiana, Guyana, Panama, Paraguay, Peru, Suriname, Trinidad and Tobago, Uruguay, and Venezuela. The nominate subspecies is cut off by the Andes Mountains and lives east of the range in Ecuador, Peru, and Bolivia; it is not found in the southeastern interior of Brazil. The subspecies avicenniae is found in coastal southeastern Brazil, around São Paulo.
The grey-necked wood rail’s natural habitats are subtropical or tropical moist lowland forests, subtropical or tropical mangrove forests, and subtropical or tropical swamps. The subspecies avicenniae, however, is almost completely restricted to mangrove forests.

Grey-necked wood rail

This bird can be seen to perch in both shrubbery and even trees, something characteristic of the forest rails. The grey-necked wood rail rarely flies, although when it is flushed out, it will generally move to a branch close to the ground. If it is being observed, it is generally cautious.
The grey-necked wood rail’s nests are situated in trees and bushes, usually 1 to 3 metres (3.3 to 9.8 ft) off the ground, built on flat branches or in thickets and lined with twigs and leaves. They generally have a diameter between 30 and 40 centimetres (12 and 16 in) on the outside, with an internal diameter of around 15 centimetres (5.9 in). The depth is usually between under 4 and 9 centimetres (1.6 and 3.5 in). The overall height of the nest is around 16 centimetres (6.3 in).
This bird feeds at night, eating various invertebrates and small vertebrates. While in mangroves, it commonly feeds on crabs. Otherwise, it will generally feed on molluscs, arthropods, frogs, seeds, berries, palm fruits, and the occasional water snake. Maize, rice, and bananas are also viable food items for the grey-necked wood rail. I
When eating snails, this rail will hammer at the shells to extract them. For berries, it will jump high to break off clusters of this fruit. After doing this, it will pick off the berries one by one and eat them. It uses its partially open bill to probe and move aside debris like leaf litter. It is generally wary and secretive, and selfish when mated. This manifests in warning its partner with threat displays to keep it at a distance. Even so, it has occasionally been seen to openly forage in short grass near thickets and in streams or muddy tracks. [Source: Wikipedia]