50 BRITISH SEA BIRDS. 



COMMON TERN. 



This Tern, known as the Sterna hirundo of 

 Linnseus, by most British ornithologists, although 

 there can be little doubt that the great Swedish 

 naturalist applied the term indiscriminately to this 

 and the Arctic Tern, is one of the best known 

 British species, especially round the English and 

 Welsh coasts. It becomes rarer in Scotland, where 

 it is largely replaced by the Arctic Tern. The 

 Common Tern, distinguished by its white under- 

 parts from the Arctic Tern, is migratory and 

 arrives on the British coasts towards the end of 

 April, retiring south in Autumn. Its favourite 

 haunts during the summer are the various groups 

 of low rocky islands, and the more secluded portions 

 of the coast where sandbanks and shingle occur. 

 Save on passage, this Tern is seldom seen far from 

 the vicinity of its nest colony. The flight of the 

 Common Tern is exceedingly buoyant and graceful, 

 the long slender wings and acutely forked tail 

 assisting greatly in the general effect. Like the 

 Swallows the tarsus of the Terns is remarkably 

 short, so that on the ground the birds seem awkward, 

 and rarely attempt to walk far; on the sea, however, 

 they are quite at home and swim well. There are 

 few prettier sights along the shore than a flock 

 of Terns busy in quest of food. Where the beach 

 is rocky, and the water somewhat deep inshore, the 



