Page:GrouseinHealthVol1.djvu/112

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52
THE GROUSE IN HEALTH AND IN DISEASE

still quite bare, and now, of course, this feature may truly be taken to be a sign of sickness and disease, though in a convalescing bird.

In October one may find a very backward bird with as many as three worn-out primaries in either wing to change; but, as a rule, the wing is October. perfect, the primaries and secondaries and their coverts all completely new, and in the tail the rectrices are full grown. The legs and feet are now also fully feathered, though the thickness of the growth increases as the winter cold comes on. On the back the bird now looks fresh and richly coloured, from head to tail, but a close search will always disclose a number of spring-plumage feathers which have still to be thrown off. Underneath, the rich red-copper colour is gradually replacing all the previous buf on the chin and throat. The change "hangs fire" a little on the neck and upper breast, but it is still progressing, whereas on the lower breast and belly the rich red or darker winter plumage with its beautiful fine black cross-lines and pure white flecks is a very striking feature.

There are, in the Committee's collection of skins, a number of examples showing the result of disease in deferring the moult; many of these birds, even in October and November, have made no effort to get rid of the old, faded and completely worn-out spring plumage. The majority of these birds have been so diseased in spring that they have not bred at all. The ovaries have throughout the season shown no development, and there are no signs, even in the earlier months, of the shedding or development of ova or of any increase in size of the oviduct. They have been true barren hens. In some cases (e.g., in No. 1247) there appear, in November, feathers of three separate plumages. There are the faded spring-plumage feathers of the current year, but mixed up with them here and there are new feathers of the autumn plumage coming, and here and there exceedingly old worn feathers of the autumn plumage of the year before. No. 1225, an October hen, shows exceedingly well how the bare, broody patch of the abdomen grows delayed broad-barred buff and black feathers instead of the fine-barred darker autumn-plumage feathers which surround the patch. These broad-barred feathers appear in two parallel rows, breaking through the skin of the broody patch on either side of the medial line; this growth is also well shown in a specimen at the British Museum of Natural History (Pl. xiv.).

In November the chief alteration is the completion of the autumn moult