54 BRITAIN'S BIRDS AND THEIR NESTS. 



workings of nature. In the case in question, of course, 

 any number of causes without any bearing on the theoiy 

 of migration may have brought about the failure of the 

 introduction ; but the point remains. 



THE SANDWICH TERN 



(Sterna cantiaca). 

 Plate 18. 



The Sandwich Tern is the largest of the Terns which 

 nest in the British Isles, and approaches the smaller Gulls 

 in size. It resembles the other Terns in plumage, but the 

 legs and feet are black, and the bill is of the same colour, 

 with some yellow at the tip. The white under-parts are 

 suffused with faint salmon pink. Before summer is over 

 the black cap begins to decrease, and in winter it is repre- 

 sented by a few dark markings. The head of the young 

 bird is similarly marked, and the mantle is also mottled. 



The Sandwich Tern is no longer particularly associated 

 with the locality from which it derives its name, and many 

 of the colonies, such as those on the Scilly Isles, have dis- 

 appeared. But it is still common in parts of the British 

 Isles, and now generally receives efficient protection at its 

 haunts. On the east side of Britain it nests from the 

 Fame Islands, one of its chief strongholds, northwards to 

 Moray, and on the west from the Lancashire islands to the 

 north shore of the Solway Firth, the chief colony being 

 at Ravenglass in Cumberland. It also nests in the Orkneys, 

 and has done so in the Channel Islands. In Ireland there 

 are one or two big colonies in County Mayo. At most 

 other places on our coasts it may be seen at the migra- 

 tion seasons. Like its allies, it is of course a summer 

 visitor to the British Islands. 



