Great argus pheasant males are amongst the most unusual and distinctive of all birds, unmistakable with their astoundingly long wing and tail feathers, decoratively adorned with a complex pattern of eye-spots (ocelli). The elongated secondary wing feathers, important for flight in most other birds, have evolved instead for courtship display in this species, to the detriment of flying ability (5). Upperparts of the male are otherwise rusty-brown, finely mottled with intricate buff and black spots (4). Females are similar but smaller than males, with shorter tail and wing feathers and lacking the male’s eye-spots (4). Both sexes have conspicuous bare blue facial skin, and a black crown with a short crest (4). The Bornean great argus (Argusianus argus grayi) is slightly smaller than the Malaysian great argus (Argusianus argus argus) and can be distinguished by more burnt-orange colour on its upper breast and neck and whiter spotting on upperparts.