I was fortunate to observe 8 of these birds in a social group. This is the third time I am seeing the presumed same group at this site. They are extremely shy birds. I met them going down a slope to their feeding grounds at 8.45am and again on the return upslope at 11.30am. They have to cross a mountain road and usually dash across or fly across. My presence of course made them more cautious when crossing. This image is of a bird from the anterior view, showing the white frontal spots. Wells 1999, quoting Robinson (1928) suggests that the older birds have less frontal white. This particular bird, with lots of white, did appear to me to be immature and less confident in behaviour.
Taxonomic Notes :
Monotypic species endemic to the mountains of West Malaysia. Split from Grey-breasted Partridge Arborophila orientalis following:
Mees, G. F. (1996) Geographical variation in birds of Java. : i-viii, 1-119. Nuttall Ornithological Club, Cambridge, Mass., USA. Publ. No. 26.
Dickinson, Edward C., Editor (2003) The Howard and Moore Complete Checklist of the Birds of the World, 3rd edition. London: Christopher Helm.