( 139 ) 



ON THE POSITION OCCUPIED BY THE LEGS 

 OF BIRDS DURING FLIGHT. 



By G. E. H. Barrett-Hamilton. 



Discussions dealing with the precise method of the carriage 

 of the legs of birds in flight have, so far as I am aware, only 

 recently appeared in ornithological literature ; so that, although 

 no observant field naturalist could feel much doubt upon the 

 question, it can hardly be regarded as altogether decided. 



The legs of birds are such important aids to flight, and are so 

 constantly in use when they are on the wing, that it might have 

 been expected that a general paragraph upon the subject would 

 have found a place in some of our text-books ; but, beyond the 

 few discussions already alluded to, I have never been fortunate 

 enough to find the matter more than mentioned. 



It seems hardly worth while to make an exhaustive search for 

 allusions to the subject. Mr. Ernst Hartert* seems to have been 

 the first to draw attention to it of recent years. The species first 

 critically observed by him were the Common Kites of Calcutta 

 Harbour (Milvus govinda and Haliastur Indus). More recently 

 he had opportunities of studying the flight of the Black Kite on 

 the Rhine, the New-World Vultures of Venezuela, and Polyborus 

 cheriway in Curacao. As a result, Mr. Hartert became con- 

 vinced that all birds of prey carry their legs stretched out back- 

 ward, except when they have hold of their prey ; and in this 

 respect he classed with them all Waders, Ducks, Herons, Cranes, 

 Storks, Rails, and Game-birds. A similar observation had been 

 recorded by Herr Ziemer t some ten years previously ; he had 

 studied the Raptores of Pomerania, Corroboration was afforded 

 by Dr. P. L. Sclater| with regard to certain Gulls and the 



* ' Ornithologische Monatsberichte,' ii. (January, 1894), p. 5 ; 'Journal 

 fur Ornithologie ' (October, 1889), p. 341 ; and ' Ibis' (January, 1895), pp. 133- 

 135. 



| ' Ornithologische Monatsberichte,' 1893, p. 117. 



\ ' Ibis,' 1895, p. 876. 



M 2 



