Page:The Zoologist, 4th series, vol 6 (1902).djvu/263

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THE BLACK-HEADED GULL.
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unsettled weather. One never hears now of their mention in this connection; rather, their absence would call for comment. Undoubtedly the amount of food—insectivorous and vermiform—they consume the year round, together, of course, with the astounding increase of the Starling within the last thirty-five to forty years, may be set down as the principal factors that have caused the no less astonishing and remarkable change of habits in the Rook, that has so greatly affected the equanimity of game-preservers. The poor Rooks have been deprived of their natural and rightful share, and have been compelled to try elsewhere for a living at their most pressing time of need, in April and May.

The particular purpose of the present paper is to draw attention to the habit of the Black-headed Gull of catching moths. I first watched them do this in the fine hot and dry summer of 1868. For long subsequent to that year they could only be seen capturing moths on the wing during similar warm summers; but for at least the last dozen of years these Gulls have regularly and constantly presented this habit. Either from choice or necessity the catching of Lepidoptera after nightfall has become a confirmed annual practice. Formerly we meet, in ornithological literature, with short and fragmentary allusions to this species feeding on the Ghost Moths, picking these from the grass-stems. There seems every reason to believe that moth-catching by this species began with the Ghost Moth. Accurate observers like Blake-Knox and Robert Gray only name Ghost Moths; if other species were taken they would have been specified. One of the latest present-day notes referring to this habit is in 'British Birds, their Nests and Eggs' (vol. vi. p. 73), where Dr. H.O. Forbes says: "In summer feeds on insects, and especially moths, which it hawks on the wing." That shows how the habit has widened from "Ghost Moths" in particular to "moths" in general.

The habit in question is no mere incidental occurrence confined to a few birds in a restricted locality. It is nightly indulged in by apparently the whole of the birds, and carried on for many a mile around all the breeding colonies in certainly the lowlands of Scotland, south of the Forth and Clyde, and across most of the North of England. Where I have not had personal observation to rely on, I have had the benefit of trustworthy information.

Zool. 4th ser. vol. VI., June, 1902.
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