notes may be represented by the syllables ' ag ag ag' or ' han han han,' 

 while its alarm-notes are somewhat like ' kyaozik, kyaouk.' 



It is not so gregarious as most other Gulls. Single birds are most 

 commonly seen, and larger flocks than eight or ten birds are not often met with. 

 Even in the breeding season it is much less sociable than its congeners, 

 and only breeds in colonies where secure nesting-sites are scarce. They are 

 very quarrelsome birds, even among themselves, and I have seen several 

 fierce fights even among the members of the same little colony. 



Nest-building commences about the beginning of May, though eggs are 

 but rarely found before the second week of that month. The Great Black- 

 backed Gull takes but little pains with the building of its nest, which is 

 usually little more than a depression in the grass or hollow in the rock, 

 carelessly lined with dead grass, seaweed, and a few feathers. Occasionally 

 I have seen it carefully lined with fur and sheep's wool, but this is uncommon. 

 The favourite site for the nest is the grassy top of some inaccessible rock on 

 the coast; single pairs usually occupy these fastnesses, but if there be room, 

 and suitable nesting-sites be scarce in the district, four or five pairs will take 

 possession of the summit while the Kittiwakes cluster below. If suitable rocks 

 are not to be found, an island in some loch is utilised, often at a considerable 

 distance from the coast. 



Two, or at the most three, eggs are laid. They are not subject to such 

 variations as those of the Herring Gull or Lesser Black-backed Gull, but are 

 usually greyish brown in ground-colour, sometimes pale olive brown, spotted, 

 blotched, and streaked with surface-markings of dark brown and underlying 

 spots of brownish grey. Some specimens have the markings sparingly and 

 evenly distributed over the entire surface of the shell, while on others the 

 markings are collected on the larger end of the egg, forming irregular blotches 

 of colour. A very pale variety is sometimes found, having a pale bluish white 

 ground-colour, very sparingly marked with brownish surface spots and violet 

 grey under-markings. The eggs vary from 3^20 to 2-89 inches in length, and 

 from 2-20 to i'95 inches in breadth; very small specimens are indistinguishable 

 from large specimens of those of the Herring Gull. 



Young in down are greyish buff, shading into white on the belly, spotted 

 with black on the head and throat, and obscurely spotted with dark brown on 

 the rest of the upper parts. Legs and feet are flesh-coloured, bill slate grey, 

 irides dark brown. 



8 



