Page:GrouseinHealthVol1.djvu/109

From Wikisource
Jump to navigation Jump to search
This page has been proofread, but needs to be validated.
PLUMAGE CHANGES OF THE HEN GROUSE
49

broad-barred and the winter plumage with its very fine black cross-lines (PI. xii., Figs, e, f, l, and n).

The legs and feet in July are naked, and the claws are very small; but the feathers are already showing through as small white points, not to be confused with broken shafts, which occasionally result from wear and tear in woody heather.

The plumage of the hen Grouse in August is well known. It has already been pointed out how, owing to the sudden increase of observation, and owing to the sudden arrival of opportunities for examining an enormous August. number of birds over the whole country during this month, there has sprung up an idea that disease amongst Grouse has a recrudescence in the autumn. But this is not the case. There are probably fewer diseased No
autumn
outbreak
of disease.
birds on the moor in August than there are in July. In July, however, they are never shot, and therefore not investigated, but in of August they are carefully picked out of every bag, and, owing to the general interest in the question of disease, are almost always noticed, and in a large proportion of cases publicly notified. Hence the idea that disease makes a new start in August and September. As a matter of fact, however, these wasted birds are almost certainly convalescent. They have been diseased, and they are still suffering from disease, but thanks, in the majority of cases to their sex (for the bulk of the sickly autumn birds are hens), they have avoided actual death in the two highest mortality months, April and May. Once tided over these fatal months, the food and general conditions of life improve, the weight of the cock goes up, and the balance is again in favour of recovery for him; and although with the hen the exigencies of incubation and the cares of the family continue to handicap her until June and even July, she then rapidly begins to put on weight, and in August and September is once more on the way towards complete recovery. Many sick-looking "piners" are shot upon the moors in August, but it should be remembered that in that month they are recovering from disease, and not growing worse; while in September many that were not up to the average weight the month before will be practically normal and probably indistinguishable from healthy birds, were it not that their serious indisposition of the preceding months has put them behind their fellows in the matter of feather change.

In August, therefore, the Committee's collection of skins contains a large number of examples of hen birds showing deferred moult and belated growth