488 BIRDS OF THE WEST OF SCOTLAND. 



the air, letting them fall among the stones so as to break the 

 shells and enable them to get at the contents. I had previously 

 seen rooks at this ingenious employment, but I never before saw 

 or heard of gulls exercising their instincts in this manner. 

 Mr Watson, of Stranraer, informs me that he has frequently 

 observed Herring Gulls breaking mussels in the same way. The 

 same gentleman showed me a specimen which he had killed by a 

 rifle shot at a distance of 150 yards. The ball had entered the 

 forehead of the bird as it sat on the water, and drilled a tolerably 

 neat hole through the cranium. Mr Watson had previously shot 

 gulls at greater distances in different parts of the body with the 

 same rifle. 



THE GKEAT BLACK-BACKED GULL. 



LARUS MARINUS. 

 Farspach. 



THIS large and powerful bird is much more common in the remote 

 northern districts than in the southern counties. There are 

 several breeding stations within a few hours' journey of Glasgow. 

 Two of these are very dissimilar in their character, one being 

 situated near the summit of Ailsa Craig, and the other on the 

 island of Inchmoin in Loch Lomond. In the former locality the 

 nests are on the grassy slopes of the rock, and are mere hollows 

 formed in the turf with a very scanty lining; but in the inland 

 nursery they are formed of materials similar to those used by the 

 lesser black-backed gull, and are generally found among coarse 

 grass and bushes- of heath. Twelve or fourteen pairs annually 

 take up their quarters on Loch Lomond, in the island just named, 

 but seem to keep aloof from the other species frequenting the place, 

 repairing in the daytime to the upland glens, where they occasion- 

 ally fall in with dead sheep and other animals, on which they 

 surfeit themselves. In the evenings they may be seen returning 

 to the loch sailing majestically over the tree tops, or hovering a 

 minute or two above the banks of the brawling torrent to pick up 

 some stranded object. 



In the Outer Hebrides there are breeding colonies on nearly all 

 the islands. There are several in Lewis, which occupy small grass- 



