THK BLACK- HEADED GULL. 331 



The black-headed are less wild than any other species of gull in 

 Belfast Bay, and are often to be seen feeding very near the road 

 bounding its western side, even when the tide is out, and a great 

 extent of banks uncovered. I have remarked them within 

 forty yards of it, and have been occasionally much interested in 

 observing the excellent vision they possess, as evinced by theii' 

 making " stoops" from a height of ten or a dozen yards at ob- 

 jects on the ruffled surface of the water so minute that they could 

 not be perceived in their bills, though they evidently never failed 

 to seize something. When feeding on the ooze of the Lagan, I 

 have been amused at their suddenly turning back, and using their 

 wings for a yard or two in pursuit of prey which the stream had 

 carried past them : their advantage over wading birds, too, is some- 

 times obvious, as they resort to swimming when other means will 

 not bring them to the desired object. I have sometimes remarked 

 that large flocks feeding here obtained their food entirely on the 

 ooze, without approaching even the margin of the river. 



As a difference of opinion exists about certain species of birds 

 eating slugs, or shell-less snails, on the 10th of August, 1833, I 

 tried four young black-headed gulls with different species of 

 them ; the small yellowish one [Limax agrestis), the young of the 

 speckled {L. maximus), and the small blackish one with orange belly 

 [Arion hortensis) . These were offered to the gulls after their 

 usual daily time of being fed was past, and when they were ex- 

 tremely vociferous for food. On the slugs being presented, they 

 all four dashed open-billed upon them, and picked up a slug 

 each, which was no sooner done than they one and all flung 

 them violently a^ay with evident disgust : some of them re- 

 turned a second time to the charge, and again picked up a 

 slug, but this was as rapidly expelled as at first : thus termi- 

 nated the feast of slugs."^ They were usually fed on the entrails 

 of fowls. 



With respect to the black-headed gull itself as food, a corre- 

 spondent remarks, that he has found it " suflicieutly palatable, and 



* For (lucks feeding on tlicm, sec p. 84. 



