102 EGGS OF BRITISH BIRDS. 



THE COMMON TEEN. 

 (Sterna hirundo.) 



Plate 29, Figs. 1, 3. 



Next to the Arctic Tern, the Common Tern is perhaps the best 

 known British species, although it is, especially in the north, 

 much less abundant. Like the Arctic Tern, it is an Atlantic 

 Ocean bird, but does not range as far north as the latter species. 



The Common Tern often lays its eggs within a few feet of the 

 water, and in many cases dispenses with a nest altogether. It 

 generally establishes its colony on a bare shingly portion of the 

 beach, or amongst the scant herbage of an ocean rock. 



The eggs are two or three in number, never more. They vary 

 in ground-colour from pale greyish-buff to brownish-buff, occasion- 

 ally with a tinge of green. The overlying spots are dark brown, 

 sometimes almost black, and the underlying spots are grey. 

 The spots are generally small, less than the size of a pea, and 

 are distributed somewhat sparingly over the whole surface, but 

 sometimes in a band near the large end of the egg. Occasionally 

 a few of the spots are confluent and form a large blotch, and 

 in very rare instances streaks are to be found. They vary in 

 length from 1*8 to 1*5 inch, and in breadth from 1'3 to 1.15 

 inch. They cannot with certainty be distinguished from eggs 

 of the Arctic Tern or Roseate Tern. 



THE ARCTIC TERN. 



(Sterna arctica.)* 



Plate 29, Figs. 10, 12. 



This is the Tern par excellence of the British coasts, and 

 especially north of the Tweed. It breeds in the Shetlands (where 

 it replaces the Common Tern), in the Orkneys, throughout the 

 Hebrides, and in all suitable places on the entire coast-line of Scot- 

 land, but always prefers an island to the mainland. On the east 

 coast of England its great stronghold is on the Fame Islands ; 

 while on the west it breeds on the shores of Cumberland, on 

 Walney Island, and in a few localities on the Welsh coast. On 



* Sterna macrura — Saunders, Manual, p. C33. 



