Domestic chickens were derived from the wild Red Junglefowl Gallus gallus. A survey of 745 museum specimens of Red Junglefowl suggests that most wild populations have been contaminated genetically by introgression of genes from domestic or feral chickens. A male eclipse plumage, which appears to be an indicator of pure wild genotypes, was found in populations in the western and central portions of the species's range, but not in the easternmost populations. Eclipse plumages probably disappeared from extreme south-eastern Asia and the Philippines prior to the advent of intensive scientific collecting (about 1860) and have not been observed in Malaysia and neighbouring countries since the 1920S. Populations exhibiting eclipse plumages were found in north-eastern India as late as the 1960s, but the dense human populations there make their continuing genetic integrity uncertain. These data suggest that surveys of wild and captive populations should be undertaken to assess the genetic integrity of this species. A re-evaluation of the conservation status of Red Junglefowl might then follow.