46 BRITAIN'S BIRDS AND THEIR NESTS. 



other inland waters, but more often near the coast. 

 There, any low -lying island or tract of open waste 

 land may be the site of a colony of from an3rthing up 

 to several thousand pairs. But it is especially the 

 sandy wastes that we have described that are the typical 

 haunts of the Common Tern during the nesting season. 

 When we invade such a sanctuary of bird-life and reach 

 the top of one of the dunes encircling one of the large 

 hollows, a thick cloud of these graceful birds rises 

 before us. They remain flying about above the nests 

 they have just left, uttering loud discordant screams, 

 harsh and grating to the ear. Now and then, in 

 a curious manner, all become simultaneously silent, and a 

 lull ensues, to be suddenly broken in a few seconds by 

 the renewal of the clamour. 



We descend to the hollow in search of nests, but are 

 at first unsuccessful. Then all at once we come on one 

 so suddenly that our next step would have destroyed it. 

 A few steps more and we almost tread on a second, and 

 we find ourselves in the midst of the colony, for, as oui' 

 eyes get accustomed to distinguish the eggs from their 

 surroundings, we begin to see them on every side. The 

 eggs do indeed harmonise well with the sand. The coloiu* 

 is very variable, ranging from light buff or pale green to 

 rich, warm brown. The markings may be blotches or 

 mere speckles, and are generally of a very dark brown, but 

 purplish under-markings are usually present also. Three 

 eggs form the full clutch, but two are very common. 

 The eggs in a clutch frequently show considerable 

 resemblance to each other, but are often totally different. 

 It is not very uncommon, for instance, to find one egg 

 pure white or unspotted light blue, or some such abnormal 

 colour, while the others are of a commoner type. 



The nests are very primitive affairs. Often the eggs 



