Expedition to the Eastern Canary Islands. 267 



Puffinns kuhli flavirostris. Yellow-billed Shearwater. 

 Pufinus k. flavirostris (Gould) ; Eannerman_, Part I. pp. 61, 

 64, m, 67, 68, 69, 70, 80, 83, 84, 87, et Bull. B. O. C. 

 xxxiii. 1913, pp. 56-57. 



A very large series o£ this Shearwater was obtained, all 

 adult breeding birds. The differences which exist between 

 this and the Mediterranean form P. k. kuhli have been clearly 

 set forth by Dr. Hartert and Mr. Ogilvie-Grant (Nov. Zool. 

 1905, p. 97), and need not be enlarged upon. The following 

 points in the series which I obtained are worthy of note : — 

 It has already been remarked that the sex of this Shearwater 

 can be accurately told when the bird is alive by the size of 

 the bill and tarsus. The following measurements give the 

 relative length of 25 male and 15 female examples : — 

 Bill, c? 53-57 mm. 

 ,, $ 50-53*5 (many beaks measure 53 mm., but one 

 example has an abnormally long bill of 55 mm.). 

 Tarsus, c? 56-585 mm. 

 „ ? 51-51'5 mm. 

 Wing, c? 337-374 mm. 

 ? 344-367 mm. 

 But more important than the actual length is the relative 

 build of the bill and tarsus, that of the male being much 

 heavier and stouter than that of the female. 



For a complete account of the nesting habits, distri- 

 bution, etc., of this species in the eastern Canary Islands 

 see Part I. p. 66. 



The Yellow-billed Shearwater swarmed on all the smaller 

 islets and rocks of the eastern group, but was particularly 

 numerous on Graciosa and Montana Clara. It also nests, 

 according to the natives, at the foot of El Risco in Lanzarote^ 

 but I did not have an opportunity of verifying this state- 

 ment. In Fuerteventura Polatzek found it breeding " in a 

 crater near the mountains of Oliva about eight kilometres 

 from the sea-coast ^^; the same observer records a nesting 

 colony " within an hour's journey to the north-west of 

 Yaiza," in Lanzarote. 



There is also a large colony on the island of Lobos. The 

 natives call this Shearwater " Pardela.''^ 



