300 GREAT BLACK-BACKED GULL. 
at least when seen only in flight. It is chiefly seen in 
pairs in its adult plumage, is a comparatively shy and 
wary bird, and may be said to be generally distributed 
around the coasts of Scotland and England after the 
season of incubation, frequenting estuaries, but sel- 
dom straying far from the sea or inland along the 
course of rivers. In Ireland, from all our records, its 
frequency and habits at this season are nearly similar. 
In Europe, it has been found on tho Italian shores, 
and in Sweden and Norway, but we have no notice 
of its abundance or rarity there. Towards the arc- 
tic circle it becomes rare, but by Audubon is given 
to North America, breeding on the shores of Labra- 
dor for an extent of three hundred miles ; in winter 
the young migrate as far as the Floridas. In Asia 
or Africa we appear yet to possess no authentic 
traces of its existence. The Great Black-backed 
Gull breeds chiefly in marshes, and on the kind of 
tracts called in the northern islands of Scotland 
“ Holmes,” being elevated flats of rather wet muir 
or muirish meadow ; the low lands about the estu- 
ary of the Thames being an example of tho first, 
where Mr. Yarrell observes that this bird frequently 
breeds. In Orkney and Shetland, however, Mr. 
Hewitson tells us that it breeds in places nearly 
inaccessible, and in large companies, the space of 
half an acre supplying in one year no less than 
sixty dozen of eggs. We have ourselves observed 
a few pairs breeding on the Bass Rock in the Firth 
of Forth, and in one or two similarly insulated 
situations, and the nest was always placed on the 
