The crimson-headed partridge is a species of bird in the pheasant, partridge, and francolin family Phasianidae. Described by the British ornithologist Richard Bowdler Sharpe in 1879, it is the only species in the genus Haematortyx. It is endemic to Borneo, where it inhabits lower montane forest in the northern and central parts of the island. It is mainly found at elevations of 1,000–1,700 m (3,300–5,600 ft), but can be seen as low as 185 m (607 ft) and as high as 3,050 m (10,010 ft). Adult males have a striking appearance, with a dark blackish body and crimson red heads, necks, breasts, and undertail coverts. Females have a similar pattern, but with duller brownish-black colouration, orangish-red heads and breasts, and a brownish-black bill instead of a yellowish one. Juveniles are duller and have the crimson restricted to the top of the head.

The peacock-pheasants are a bird genus, Polyplectron, of the family Phasianidae, consisting of eight species. They are colored inconspicuously, relying on heavily on crypsis to avoid detection. When threatened, peacock-pheasants will alter their shapes using specialised plumage that when expanded reveals numerous iridescent orbs. The birds also vibrate their plume quills further accentuating their aposematism. Peacock-pheasants exhibit well developed metatarsal spurs. Older individuals may have multiple spurs on each leg. These kicking thorns are used in self-defense.