Giant Wood-Rail Aramides ypecaha Scientific name definitions

The Giant Wood-rail is a large, terrestrial rail of south Brazil and Uruguay, eastern Paraguay, and northeast Argentina.  While most Aramides are shy and inhabit thick vegetation, the Giant Wood-rail lives along marshes and rivers, and can often be seen completely out in the open, walking slowly along the mud.  This behavior generally comes as a great and welcome surprise to neotropical ornithologists familiar with the effort involved in aquiring even partial views of wood-rails elsewhere.  The plumage of the Giant Wood-rail is a composition of earth-tones, with a rich olive back fading to umbre-rust towards an abrubt cutoff with a gray face and chest. The underparts are salmon on the flanks and whitish gray  on the belly. The tail and tail coverts are black, and the eye and legs are red. The large, slightly downcurved bill is bright mustard yellow. The Giant Wood-rail inhabits gallery forest and tropical and subtropical marshes and wetlands, and is typical in the large wetlands of Iberá and Entre Rios.

41–45 (possibly up to 53) cm; two females 640–765 g. Sexes alike; female slightly smaller. Largest Aramides; handsome bird , with pale bluish grey face and foreneck , olive upperparts, and delicate brownish pink flanks and upper belly; underwing-coverts chestnut with black bars; stance upright, gait elegant. A. cajaneus has rufous or brown-black patch on nape, but grey hindneck; A. saracura and A. calopterus darker and extensively grey below, and latter has striking reddish chestnut on side of neck and upperwing-coverts. Immature slightly duller than adult; legs brownish red; bill has brownish tinge. Juvenile not described.

EC & SE Brazil, E Bolivia (1 Quillén, J. (2009). [New departmental records of birds in Bolivia]. Kempffiana 5(1): 72–77. In Spanish. Close ), Paraguay, NE Argentina and Uruguay.

Open marshes, lightly wooded swampy areas , fields and pastures near water and cover, and gallery forests; more likely than other Aramides species to appear in the open . Restricted to lowland areas .

None recorded.

Little information available. Recorded taking a snake  . Recorded digging the soil with the beak while foraging . In captivity, eats insect larvae, eggs, minced meat, apple and meal.

Calls during day and also in evening, when birds congregate in selected spots and set up an astonishingly powerful, even deafening, chorus of screams, shrieks and wheezes, rushing frenziedly about with wings spread and bill raised vertically. Calls described as: reminiscent of a hysterical human saying “all..wacky....all..wacky”; also a piercing, high, single “eeeeeeok”, a bark, a low “keaaw” and an explosive “puk”.

Nest of grasses and weed stems, c. 30 cm in diameter, built 1+ m above water, in shrub or broken-down vegetation. Eggs 4–5; chicks  dark mahogany brown. Other information from captive breeding: eggs laid at daily intervals; incubation 24 days, by both sexes; chicks left nest after 3–4 days; fed and cared for by both parents for 8–9 weeks; last brood stayed with parents for over 3 months; chicks half-grown at 5 weeks; renesting occurred when young of first brood 6 weeks old; 3 clutches laid in season.

Not globally threatened (Least Concern). Formerly common to abundant in much of its range; in 1980s was common in Rio Grande do Sul, Brazil, where it is a frequent victim of steel traps set in marshes for fur-bearing animals. Often kept in captivity in South America. No recent information on status, but species must have decreased in numbers as a result of extensive habitat destruction.