238 



THE ANIMALS OP NEW ZEALAND 



Northern Hemisphere, which wanders as far south as Florida ; 

 so that probably L. dominicanus spread from South America. 



At first, it seems singular that our gulls should be different 

 from those of Tasmania and Australia. But we must remember 

 that gulls find their natural food on the seashore, and do not go 

 much to sea except when they are following ships ; and even then,, 

 it is only the skuas which go out of sight of land. Terns, on the 

 contrary, live entirely on fish or crustaceans, which they take out 

 of the water, and, consecpiently, they are more oceanic and more 

 widely spread than the gulls. 



Black-backed Gull. 



Key to the Species. 



1. Back sooty black. 

 Back peaii-grey. 



2. Quills white on both sides of the shafts. 

 Inner web of first quill mostly black. 



((iriiii's Gciwra of Birds., 



L. dominicanus. 



L. buUeri. 



L. scoi)ulinus. 



The Black-backed Gull. — Karoro. 



Laius dominicanus. 



AVhite M-ith black back and wings, the secondaries tipped with white. 

 Eye, white. Yovmg, brown, getting mottled with white as they grow 



