THE BLACK-HEADED GULL. 217 



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 atten- 

 tion 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 con- 

 firmed 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 con- 

 fined to a few birds in a restricted locality. It isnightly 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 observa- 

 tion to rely on, I have had the benefit of trustworthy information. 

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



