578 LARUS CANUS. 



Male in Winter. — The bill is greenish-yellow, purer 

 toward the end ; the margins of the eyelids vermilion. The 

 plumage is coloured as in winter, the only difference being 

 that the spots on the head and neck have disappeared. 



Female in Summer. — Similar to the male. 



Habits. — The fields having been cleared of their produce, 

 and partially ploughed, to prepare them for another crop, the 

 " Sea Maws," deserting the coasts, appear in large flocks, 

 which find subsistence in picking up the worms and larvae that 

 have been exposed. These flocks may be met with here and 

 there at long intervals in all the agricultural districts, not only 

 in the neighbourhood of the sea, but in the parts most remote 

 from it. Although they are more numerous in stormy 

 Aveather it is not the tempest alone that induces them to 

 advance inland ; for in the finest days of winter and spring 

 they attend upon the plough, or search the grass fields as 

 assiduously as at any other time. Frequently they have no 

 companions of other species, but often they mingle with Tar- 

 rocks, and sometimes with Herring Gulls. Should the 

 country become covered with snow they retreat to the shores ; 

 but when the thaws have partially exposed the ground they 

 return. At this season they almost entirely desert the more 

 northern sterile parts of Scotland, advance southward, and 

 are dispersed over the whole country. At length, in the end 

 of April they disappear from the interior, and betake them- 

 selves to their breeding places. 



In the Shetland and Orkney Islands, in the Outer 

 Hebrides, on the northern and western coasts of Scotland, 

 here and there in the rocky places along its eastern shores, 

 and much more rarely on the western coasts of England and 

 Wales, they are then to be found, often congregated in vast 

 numbers, but also dispersed in pairs. The lower parts of 

 craggy cliffs, rocky peninsulas, and small unfrequented 

 islands, are their favourite stations. I have often, however, 

 found their nests on the turf, along with those of the Herring 

 Gulls. They are composed generally of fuci, occasionally of 

 grass, bits of turf, and other vegetable substances. The eggs, 



