Crimson-headed Partridge

A striking species of partridge, the crimson-headed partridge has an average length of around 25 cm (9.8 in) and the weight of one measured male was 330 g (12 oz). Adult males have a distinctive appearance; the heads, necks, and breasts, along with the final section of the undertail coverts, are crimson red, while the rest of the body is dark blackish. The bill is yellow to yellowish white, the iris is brown with a yellow orbital ring, and the feet are grey with one to three tarsal spurs. Adult females have a similar pattern, bur differ in their duller and browner plumage, more orangish red on the head and breast, brownish-black bill, and lack of spurs. Juveniles are duller and have the crimson restricted to the top of the head, with a brownish orange head, rust-red markings on a blackish-brown breast, and red tips to the wing coverts. The species is unlikely to be confused with any other, with its colouration only resembling that of an immature male black partridge (Melanoperdix niger). It can be told apart from the latter by the black partridge's broader black bill.

Vocalisations. The crimson-headed partridge's song is harsh, loud, repeated call rendered as KRO-krang, kong-krrang, or whu-kweng. It is frequently given alternately by two individuals. A grating, clucking kak-kak-kak, ok-ak-ok, krak-krak or whu-keng-keng-keng-kok-kok is also made when excited.

The crimson-headed partridge is endemic to Borneo, where it inhabits mountains in the northern and central parts of the island. It is found in lower montane forest, including kerangas heath forest, alluvial forest, and poor quality forest in sandy soils. It is mainly seen at elevations of 1,000–1,700 m (3,300–5,600 ft), although it has been recorded as low as 185 m (607 ft) and as high as 3,050 m (10,010 ft).

The species' generation length (average age of parents in the population) is five years. It feeds on berries, insects, and small crustaceans, foraging these from the forest floor and short vegetation. Nesting occurs in kerangas forests, with nests of dry leaves being built in tussocks of grass or lichen. Egg laying has been reported from mid-January onwards, with breeding males reported in March and young in April. Clutches have 8–9 light brown eggs with dark yellowish-brown streaking. Incubation takes 18–19 days in captivity.