232 THE ANIMALS OF NEW ZEALAND 



The Caspian Tern. — Tara-nui. 

 Hyd)vprogne caspia. 

 White with the back and wings ash-grey. Top of the head black in 

 the spring, but white spotted with black diiring the rest of the year. 

 Bill red; legs black; eye dusky. Length of the wing, 16 in.; of the tarsus, 

 1.65 in. Egg — Greyish white, sparingly spotted with dark grey and 

 brown; length 2.6 in. Found over almost the whole world, except 

 Polynesia. 



Of this fine bird, JMr. Potts says : — ' ' It is content with merely 

 a hollow scraped in the sand, just large enough to contain the 

 eggs. The breeding season extends from November to January. 

 When the Caspian terns are disturbed at breeding-time, they 

 ascend to a great height, and hover around the intruder, uttering 

 loud screams." The bird's favourite breeding places are spits 

 of land running out from the shore. It is a solitary bird. 



Genus Sterna. 



Tail very long, more than three-fourths of the wing, the outer 

 feather longest. Bill rather stout. Tarsus less than the middle 

 toe and claw. 



New Zealand properly possesses only five kinds of terns, as well 

 as four tropical species which occur at the Kermadec Islands. 

 And of these five, only one species, *S'. alhistriata, is peculiar to 

 New Zealand. This species is allied to S. vittata, which breeds 

 in the southern islands of New Zealand, as well as in Kerguelen 

 Island and other islands of the South Atlantic. This species, 

 again, is related to S. macrura of the Northern Hemisphere. Aviiich 

 penetrates southwards to Peru and Brazil in the winter, so that 

 the ancestors of S. alhistriata probably came to us from South 

 America. S. frontalis, which is also found in Australia, seems to 

 be related to >S'. hergii of India and Australia, so that it probably 

 came to us from South Asia. S. nereis, which is also an Australian 

 bird, is related to S. sinensis of India and the Malay Archipelago. 

 The Caspian tern is widely spread over the world, but is not 

 found in South America, so that we must add it also to our list 

 as coming from South Asia. 



