CATALOaVE OF BIRDS. 185 



coast, I have never myself been so fortunate as to 

 witness a single instance where this was the case ; 

 the whole of the breeding- stations that I have met 

 with being either on islands, in fresh-water lochs, or 

 on the open moors in the Highlands. 



There is a colony on a small hill loch in Glenlyon, 

 in the north-west of Perthshire, where I have 

 frequently observed scores of these birds sitting on 

 the tops of the trees, many of the highest branches 

 being killed by their excrement. The nests are 

 usually located amoug the rough stones and roots on 

 the ground ; but in two instances I have found them 

 placed in the branches of the trees, though never at a 

 greater height than about four feet. 



This bird is most destructive to the Smolts, or 

 juvenile Salmon, being often noticed feeding on the 

 shallows of the rivers ; it also preys on young birds, 

 and is accused (though I have never myself observed 

 it) of devouring the eggs of game. 



The specimens in the case were obtained at the 

 islands in the Lochs of Roro, in the north-west of 

 Perthshire, in June, 1867. 



COMMON GULL.— (WiNTEK.) 



Case 239. 



The mature bird in its winter dress, and the young in 

 the immature stage, are shown in the present case. 



Though feeding on fish, if it comes in their way, 

 these birds during winter, when on the coast, appear 

 to have a partiality for the mouths of sewers in the 

 neighbourhood of large towns ; here they are able to 

 vary their diet with a choice selection of tit-bits : a 



