 Instead of grey , several later authors described the body as brown and the head as bluish @-@ lilac , based on stuffed specimens , and this has become the orthodox image of the bird . Live birds were never described with these colours . Hume has proposed that this colouration is an artifact of the taxidermy specimens having aged and being exposed to light , which can turn grey and black to brown . Such a transformation has also turned an aberrant <unk> specimen ( sometimes referred to as a distinct species , Townsend 's <unk> , <unk> townsendi ) from grey to brown . The two extant specimens also differ from each other in colouration . The Paris specimen has a greyish @-@ blue head , and a brown body , paler on the underparts . Its tail and wing feathers were severely damaged by sulphuric acid in an attempt at fumigation in the 1790s . The Vienna specimen is a pale brown on the head and body overall , with an irregular distribution of white feathers on the tail , back , and wings . 
