THE 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 their 
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 (A. maximus ), and the small blackish one with orange belly 
(. Avion 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 away 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 “ sufficiently palatable, and 
* For ducks feeding on them, see p. 84. 
