6 ZOOLOGY OF THE VOYAGE OF THE BEAGLE. 



distance of about three yards from them ; but no notice whatever was taken of it. I 

 then threw it on the ground within one yard of an old cock bird ; he looked at it for a 

 moment with attention, but then regarded it no more. With a stick I pushed it 

 closer and closer, until at last he touched it with his beak : the paper was then 

 instantly torn off with fury, and at the same moment every bird in the long row 

 began struggling and flapping its wings. Under the same circumstances, it 

 would have been quite impossible to have deceived a dog. 



When the condors in a flock are wheeling round and round any spot, their 

 flight is beautiful. Except when they rise from the ground, I do not recollect 

 ever to have seen one flap its wings. Near Lima, I watched several of these 

 birds for a quarter and half-an-hour, without once taking off my eyes. They 

 moved in large curves, sweeping in circles, descending and ascending without 

 once flapping. As several glided close over my head, I intently watched, from 

 an oblique position, the separate and terminal feathers of the wing ; if there 

 had been the least vibratory movement, their outlines would have been blended 

 together, but they were seen distinct against the blue sky. The head and neck 

 were moved frequently, and apparently with force. If the bird wished to 

 descend, the wings were for a moment collapsed ; and then, when again 

 expanded with an altered inclination, the momentum gained by the rapid 

 descent, seemed to urge the bird upwards, with the even and steady movement 

 of a paper kite. It was a beautiful spectacle thus to behold these great vultures 

 hour after hour, without any apparent exertion, wheeling and gliding over moun- 

 tain and river. 



In the garden at Valparaiso, where so many condors were kept alive, I 

 observed that all the hens had the iris of their eyes bright red, but the cocks 

 yellowish-brown. In a young bird, whose back was brown, and ruff not white, 

 (but which must have been at least nearly a year old, as it was then the spring) I 

 observed that the eye was dark brown : upon examination after death, this 

 proved to be a female, and therefore I suppose the colour of the iris changes at 

 the same time with the plumage. 



