Page:The Zoologist, 4th series, vol 3 (1899).djvu/584

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Abundance of the Song-Thrush near Bradford.—The chief ornithological feature of the year in this district has been the immense number of Song-Thrushes (Turdus musicus) which have bred, in marked contrast to the years 1880 and 1881. As a rule, even in mild winters and late autumn, not many are to be seen here; but on the approach of spring, mostly in February, immigrants arrive, many of which withdraw sooner or later, according to the state of the weather, to breed probably in higher latitudes. This year, at the beginning of February, a larger number arrived than usual; most of the fields in the neighbourhood of woods were literally covered, and, contrary to what usually occurs, a large majority remained to breed. Having visited the woods almost daily during the breeding season, one could not fail to be struck with their abundance; indeed, it was a matter of common knowledge even to casual observers, and we hardly ever came into contact with any gamekeeper who did not repeatedly mention this fact. Another peculiarity was that a greater proportion of nests were built on the ground, and had larger clutches of eggs than in average years. If boisterous winds prevail in early spring a greater proportion of nests are built on or nearer the ground, or on more shielded places than would otherwise be the case; but, taking this factor alone into consideration, will not account for the exceptional phenomena of the present year. It is hardly conceivable that this large addition in numbers was bred here last year, and we cannot account for it except on the supposition that for some reason or other these birds remained here to breed, but under more favourable conditions would have bred in more northern latitudes. It would appear that some species of birds are more prolific in the north, and it is not at all unreasonable to suppose that many species of birds would be less strictly arboreal in their habits; but, be this as it may, the fact recorded requires explanation. It would be interesting to ascertain what are the habits of this species in more northern latitudes. Five eggs is the usual clutch in this district, but frequently four is the complement. Six is an exceptional number (one instance only this year has come to our knowledge), but even this latter number is sometimes exceeded. Whilst on this subject it may be said en passant how very different are the habits