This 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 1 and 3 metres (3 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.
Reference: Wikipedia