BRITAIN^S BIRDS AND THEIR NESTS. 45 



has been swift and sudden, a disaster of some great 

 wind-storm. Thus it comes that these waste-lands, among 

 which we might name the famous Culbin Sands in 

 Moray, blot out whole parishes, leaving a mere tradition 

 of former prosperity, verified occasionally by some move- 

 ment of the shifting dunes revealing for a time a church 

 steeple or a house-top. These sandy wastes support little 

 vegetation other than bent-grass, and of animal life there 

 is for the greater part of the year practically none. For 

 some weeks in summer, however, many of these desolate 

 wastes become crowded nui'series of bird-life. The sandy 

 hollows teem with birds hatching their eggs and rearing 

 their young. And among these the most numerous and 

 the most noticeable are the Terns of various species. 



The Terns are closely related to the Gulls, which they 

 resemble in many essential as well as in many obvious 

 ways. The plumage of the typical Terns is veiy gull- 

 like. All four common British Terns have the plumage 

 mostly white, except for the gray mantle and the black 

 cap. This latter is lost to a greater or less extent in winter, 

 and is represented in the immature plumage by a few 

 dark markings. Immature birds have also many brown 

 feathers in wings, mantle, &c. Altogether, the Terns'' 

 greatest difference from the Gulls lies in their smaller size 

 and much more slender and graceful form. In fact, the 

 long wings and the deeply-forked tail have earned for these 

 birds the popular title of ' Sea-Swallows,' an epithet whose 

 suitability no one who has ever seen a flock of them on 

 the wing would for an instant deny. 



Of the four species referred to, the most abundant in 

 our islands is the Common Tern. Like the others, it is 

 a summer visitor, arriving late in April or early in May. 

 As a breeding species it is widely distributed with us. 

 Small colonies may be found on islands in rivers and 



