OF BRITISH BIRDS 83 



Eleven species may be regarded as circumtropic. They are 

 oceanic birds which breed on islands within the tropics, and are, 

 of course, only accidental visitors of more or less frequent occur- 

 rence to our Islands : 



(Estrelata kcesitata. 

 (Estrelata torquata. 

 Bulweria columbina. 

 Puffinus major. 

 Puffinus griseus. 

 Puffinus obscurus. 

 Daption capense. 

 Oceanites wilsoni. 

 Anous stolidus. ' 

 Sterna fuliginosa. 

 Sterna ancestheta. 



NEARLY CIRCUMPOLAR SPECIES. 



Four species of birds which are included in the British List 

 are more than Palaearctic in their breeding range, but are not 

 quite circumpolar. The three first named breed regularly in the 

 British Islands, and the last is said to have done so : 



Phalacrocorax carlo. 



The breeding range of this species extends across Asia and 

 Europe to Iceland, Greenland, and the coasts of Labrador. 



Saxicola cenantke. 



The breeding range of the Wheatear extends across Asia to 

 Alaska on the one hand, and across Europe to Iceland, Greenland, 

 and the coasts of Labrador on the other. 



Pica caudata. 



The breeding range of the Magpie extends across Europe and 

 Asia to Alaska and the Western States. ' 



