THE GREAT BLACK-BACKED GULL. 
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tail, which was beautifully mottled with black and white. I have in 
different instances remarked this very handsome appearance. 
Belfast Bay . — The greater black-backed is much more frequent 
here than the lesser black-backed gull, which would appear from 
works upon the subject to be by far the more common species of 
the two everywhere in England and Scotland. It should perhaps 
rather be said that L.fuscus is rare in this estuary, than that 
L. marinus is more common than elsewhere, but the following de- 
tails will afford data on this point. Here old or young of this species 
may be seen almost every day of the year, the former at all times 
except in the breeding season, and the latter even then. The 
period of their leaving for nidification is late. On the 5th of 
May, 1832, I saw several, and on the 2nd of that month, in 
1838, observed two adult and five immature birds in com- 
pany.* On the 30th of June, 1812, three or four adult birds 
appeared in the south-western side of the bay, and for an extent 
of a few miles, only two or three gulls of any other species : 
the L. marinus is often to be seen in the breeding season, 
when other gulls are very scarce. Such birds as those last 
mentioned may be considered as not breeding. At the Cope- 
land Islands too, about the middle of June, I have remarked two 
or three adult birds, which should be brought under the same 
category. 
But from September (and some time early in the month) until 
May, the greater black-backed gull is daily seen in Belfast Bay 
from the road on either side, near to which it is driven by the 
flowing tide, for it prefers standing on the beach to floating on the 
waves. Along with groups of other gulls, but generally a little 
apart from them, and at a respectful distance from each other, a 
pair, usually — (from which circumstance it is probable that the 
species is monogamous) — or four adult birds will be seen. The 
group at the outskirts of which they appear consists daily of the 
more sociable L. argentatus , L. canus } and L. ridibundus — of 
* A fine adult bird which was shot in Dublin Bay on the 21st of May, came 
under my examination (1838). On the 6th of May, 1841, I saw one in the harbour 
at Syra (Archipelago). 
