THE LIFE-HISTORY OF BIRDS 285 



But this ecdysis is not necessarily confined to the feathers, 

 for in some species the beak-sheath is partly shed periodically, 

 and in others the claws are similarly renewed. In the Com- 

 mon Puffin, for example, after the breeding season, a pair of 

 plates on either side of the beak are shed, together with a pair 

 of conical horny spurs which are developed on the rim of the 

 upper eyelid. The White Pelican {Pelicanus erythrorhynchus) 

 of North America bears during the breeding season on the 

 ridge of the beak, in the male, a curious, horny, laterally com- 

 pressed, and roughly triangular excrescence. At the end of the 

 breeding season these growths fall off, and may be gathered by 

 the bushel in the nesting colonies of the species. Some of the 

 Grouse, e.g.. Red Grouse, shed the claws of the toes. These 

 claws attain a great length during the winter — possibly to assist 

 in supporting the weight of the body when on deep snow, but 

 they are replaced later — in the breeding season — by short claws. 



As touching the age to which birds live but little can be said, 

 for but little is known. From observations made on birds kept 

 in captivity it would seem that some species are extremely 

 long-lived. Thus a White-headed Vulture is said to have lived 

 1 1 8 years in the Zoological Gardens at Vienna. An Eagle Owl 

 in the possession of Mr E. G. B. Meade Waldo lived ninety years 

 in captivity ; and at fifty began to lay eggs, rearing young from 

 this date onwards till within a year or two of death. The 

 Magpie has been known to live twenty years in captivity; 

 while many of the smaller Passeres have died, apparently, at 

 the ripe old age of sixteen years. Parrots are said to live icxd 

 years, Ravens 200. The Common Gannet takes five years to 

 reach maturity, and probably some of the Gulls take as long. 

 The Eagle probably reaches lOO years, taking ten years to 

 reach maturity. But there are no external signs by which we 

 can judge the age of wild birds after once the adult plumage has 

 been acquired. 



In rare cases it is believed the intensity of the colouring of the 

 egg may prove an index as to the age of the bird which laid it. 

 The late Professor Newton cited the case of a Golden Eagle, 

 whose history was known, in this connection. He had, in his 

 collection, a number of eggs of this bird laid during twelve 

 successive years, and these show a gradual increase, followed 

 by a gradual decline, in the intensity of pigmentation. From 



