OCR Text |
Show 116 ON THE PLUMAGE OF THE RED GROUSE. [Jan. 17, colour. Back very black, the feathers edged and barred with dark brown, greater wing-coverts black, with here and there slight brown markings; upper tail-coverts very dark brown with lighter brown marks, shading to nearly pure black at the tail. Chin black, throat very deep reddish brown ; breast black, some of the feathers slightly edged with brown, which turns to white at the centre of the breast, the sides showing more decided brown markings ; under tail-coverts same as sides, but the markings more distinct still. This bird approaches to a melanism; but as I have often come across specimens closely resembling it, I have described it as a type of one of the variations. No. 8. Female, Dec. 3, 1879.-Back of head and neck light brown, marked with black bars and spots. Back, greater and lesser wing-coverts, and tail-coverts light brown marked with black bars, some of the feathers having black spots; the tips of many of the feathers again have a very light brown spot, giving it a very mottled appearance. Outer edges of primaries slightly marked with white. The whole of the breast, sides, and under tail-coverts light brown, shading to darker brown in the centre, each feather having one or more black bars-the feathers in the centre and sides also being edged with white, as are also the under tail-coverts. This and N o . 4 most nearly resemble each other, the latter being probably the older bird. N o w I think it will be admitted that the specimens I exhibit should not be, as I maintained before, regarded as " varieties " in the vague and ordinary sense of that word. It seems to m e that we should regard them as instances of individual differences or polymorphisms- just as in the case of the Ruff (Machetes pugnax), which exhibits a degree of variability in its seasonal adornment more conspicuous, I allow, than that of the Grouse now before us, but far less permanent, since the difference in the Grouse would appear to remain, if not throughout the year, for at least several months, while that in the Ruff is confined to but a few weeks in the spring or early summer. Thus, if m y contention he just, we have in the Red Grouse-the only species of birds according to the opinion of most ornithologists which is peculiar to the British Islands, and a species which in the judgment of the best authorities is itself the modified descendant of a far more widely distributed species, the Willow-Grouse (Lycopus albus)-an amount of individual variability capable of still further and perhaps indefinite modification as to colour, should occasion arise whereby such modification might be rendered necessary for the persistence of the stock. |