36 BRITISH SEA BIRDS. 



cliff, against which the waves are for ever beating* 

 in ceaseless strife. Except during the three months 

 or so of the breeding season, this Gull is seldom 

 seen at its nesting sites. In April or May the birds 

 collect at their various stations, never quite to leave 

 them again until the young are able to fly. It is a 

 very gregarious bird, and some of these " gulleries " 

 are very extensive, containing many thousands of 

 pairs. In some localities, however, where the ac- 

 commodation is either limited or unsuitable, but a 

 few birds congregate to form a colony. The nests, 

 often made as close together as they can be wedged, 

 are built upon the ledges, shelves, and prominences 

 of the rocks. Favourite spots are where the cliffs 

 overhang, or at the entrance of a cave or hollow in 

 the precipice. They are made at varying heights 

 on the cliff, tier above tier, the lowest often within a 

 few feet of high-water mark, but the most crowded 

 places are usually about midway up from the sea. 

 The nests are large and well made, many of them 

 apparently the accumulation of years, composed 

 externally of turf and roots, with much of the soil 

 attached, and caked together. Upon this foundation 

 a further nest of sea-weed and the stalks of various 

 plants is formed, finally lined with finer and dry 

 grass, and sometimes a few feathers. The nests 

 and the cliffs in their vicinity are thickly white- 

 washed with the droppings of the birds. The 

 eggs are two or three in number, rarely four, 

 and vary from greenish -blue, through pale buff 



