216 THE ZOOLOGIST. 



THE BLACK-HEADED GULL (LARUS RIDIBUNDUS). 

 SOME MODIFICATIONS OF HABITS. 



By Kobert Service. 



For the most part lacustrine in its nesting habits, the Black- 

 headed Gull is yet by no means unknown as a strictly sea-shore 

 species at the breeding season. One small colony that varies 

 from season to season from sometimes only a dozen pairs to over 

 a hundred pairs has bred annually for many years on one part 

 or another of the grassy salt merses of the Solway to westwards 

 of the Nith estuary. 



One season this particular colony had its nests destroyed by 

 a succession of high tides in May, whereupon the birds shifted 

 over the sea-bank to a turnip field, and betwixt the rows of young 

 turnips built fresh nests of sea-wrack brought from tide-marks, 

 and successfully brought off their young. Such modifications 

 of habits are of perennial interest to field ornithologists, and 

 constitute much of the charm attached to the outdoor study of 

 birds. 



No other British Gull is so much of a land-bird as this one 

 is, and it appears to me that it is becoming greatly more attached 

 to the land in several respects than it was in by-past years. So 

 far as my own experience goes, it was in the abnormally severe 

 winter of 1878-79 that I first noted these Gulls perched in rows 

 upon house-roofs, or alighting on the streets, ox coming to the 

 back gardens and such places for food. Previously this habit 

 was only indulged in by an odd bird or two. Since then it has 

 become quite an everyday thing whenever frost of a few days' 

 duration sets in. And there can be little question that they 

 speud far longer time nowadays upon the pasture fields and 

 amongst the crops, instead of going away to the river-sides, 

 estuaries, and shores, as they once did when nesting-days were 

 over. An older generation looked upon the presence of flocks 

 of these Gulls on far inland pastures as presaging storms and 



