The Bornean Peacock-pheasant, Polyplectron schleiermacheri is a medium-sized, up to 50cm long, rufous brown and black spotted pheasant with an elongated crest and nape feathers, black below and bare red skin around bluish iris eye. The breast sides are metallic blue-green, bordering the white throat and central upper breast. Its twenty-two tail feathers are decorated with large blue-green ocelli, which may be spread fan-like in display. The female is smaller and duller brown than the male. It has a brown iris and no spurs on its feet.
The Bornean Peacock-pheasant is probably the rarest and certainly the least known of all peacock-pheasants. This elusive bird is distributed and endemic to lowland forests of Borneo.
Together with the similar Malayan Peacock-pheasant - its sister species -, and the more distantly related Palawan Peacock-pheasant it represents a basal group in its genus; their radiation probably took place during the Pliocene (Kimball et al. 2001). Being very poorly known, the Bornean Peacock-pheasant was long considered to be a subspecies of the Malayan Peacock-pheasant, but it is well distinct .
Due to ongoing habitat loss, small population size, and limited range, the Bornean Peacock-pheasant is evaluated as Endangered on the IUCN Red List of Threatened Species. It is listed on Appendix II of CITES.