104 EGGS OF BRITISH BIRDS. 



to dark buff, occasionally with a slight shade of olive, but in the 

 boldness of their spotting they very frequently equal the eggs of the 

 Arctic Tern ; otherwise they may be regarded as miniature eggs 

 of these two allied species. They vary in length from 13 to 1"2 

 inch, and in breadth from TO to 09 inch. Some of them very 

 closely resemble eggs of the Kentish Plover ; but the latter may 

 generally be recognized by their more pyriform shape, and by 

 most of the markings being streaks rather than spots. 



THE SOOTY TEEN. 



(Sterna fuliginosa.) 



Plate 30, Figs. 4— G. 



The Sooty Tern is a bird of the tropics, but on two occasions it 

 appears to have strayed as far as our islands. It is known to 

 wander to the continent of Europe occasionally, but it is mainly 

 an inhabitant of the tropical seas. 



Ascension Island, the great breeding-place of the Sooty Tern, 

 is situated a little south of the line, about a thousand miles from 

 Africa, and rather more from South America. It is said that the 

 birds only sit on a single egg ; but this is, no doubt, the result of 

 the constant robbery of the eggs, which is continued until the 

 power of producing them is almost exhausted. Hume, who found 

 this bird breeding on the Laccadive Islands, says that three is the 

 full clutch. 



The eggs of the Sooty Tern vary in ground-colour from white 

 to pale buff ; the surface-spots are reddish-brown, and the under- 

 lying spots are pale brown. The markings are generally evenly 

 distributed over the surface of the egg, occasionally somewhat 

 sparsely so, and not unfrequently displaying a tendency to form 

 a zone round the larger end. The spots are generally small, 

 ranging from the size of buck-shot downwards. The eggs vary 

 in length from 21 to 1'8 inch, and in breadth from 1*5 to 1*35 

 inch. They approach nearest to certain varieties of the Sandwich 

 Tern ; but although the spots on some examples of the eggs of 

 the Sandwich Tern may be no larger in size, they are always 

 darker in colour. 



