Page:The Zoologist, 4th series, vol 3 (1899).djvu/40

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16
THE ZOOLOGIST.

The keeper on whose beat the white Blackbird was shot assured me that he had never seen it with a mate, and that he did not believe it had nested during the two years he had noticed it about the district. Such evidence as this is, of course, not conclusive on the point, though I think it extremely probable that his conjecture was right. Had it paired and assisted in the rearing of a brood, surely some of the young would have been abnormally marked, and, in this case, he would have observed them on his daily rounds. A young and intelligent gamekeeper would let very little escape his eye.

A word about pied Blackbirds, which, to my mind, are more subject to variations of plumage than any other species. I have seen it stated—I cannot say where, for I read pages and pages on the subject of birds almost daily—that the white feathers turn in time to black, and that even in the case of albinos nature in due course resumes her sway; the argument being that, if such were not the case, we should be continually meeting with abnormal-coloured species. Again, some other writer has recorded his conviction that albinos never revert to the normal plumage, and that natural white feathers always remain white; but that when resulting from disease they will resume the proper colours at the moulting period. The cause of preternatural plumage in birds need not be gone into here, but my impression is—once white or pied, almost always white or pied; while I view with some little incredulity the contention that disease is accountable for some of our pied birds, and that when they resume their normal health they also resume their ordinary plumage. What evidence is there in support of this? Surely it is more or less assumption? It is impossible to decide offhand about disease in a bird, especially when it is at large; while the few pied Blackbirds I have known kept in cages have never reverted to the normal colouring after moulting, although I have heard tell of an instance or two to the contrary. Of course, the obvious retort to this would be that none of them owed their white feathers to disease. So be it.

I have on a few occasions found six eggs in nests of this species, but five and four are more commonly met with, while it is quite the exception for a clutch to be represented by less than the last-named number.