64 THE GOLDEN EAGLE. 



But I know of no instance of a golden eagle building its nest on 

 a tree or on a sea cliff ; although the sea eagle often selects a 

 tree by the side of a loch, and breeds on inland rocks. 



Progress towards Maturity. 



At one time the golden eagle had a twofold individuality, 

 arising from the difference of the plumage in its progress to 

 maturity, chiefly owing to the white ring on the tail of the imma- 

 ture bird, in which state it was called Falco Fulvus or ring-tailed 

 eagle, in distinction to Falco Chrysaetos, considered two distinct 

 species. And for long it was a matter of dispute — the identity 

 of the two — until Mr Selby and Sir William Jardine cleared up 

 the question by each having kept the eagles for the four years 

 which constitutes the time it takes for the bird assuming its 

 perfect adult plumage. During the first year the white ring is 

 well defined, occupying the larger and upper half of the tail, 

 but every subsequent moult lessens the white ring. The line 

 between the white and the dark brown of the lower half of the 

 tail becomes interrupted by patches of hare-brown until the 

 fourth year, when the whole tail becomes barred with hare and 

 dark brown, as in the adult bird, when no further change takes 

 place ; which is exactly the opposite of the white-tailed or sea 

 eagle, the white of whose tail at each moulting becomes broader 

 from the upper half, until the whole tail is white in the adult, 

 as the whole tail of the golden eagle is brown, except the roots 

 of the feathers (which are white). In the one case the brown 

 invades the white towards the root of the tail till all is brown ; 

 in the other, the white invades the brown towards the end of 

 the tail until all is white — the one pushing away the white 

 upivai'ds, the other pushing away the brown downwards. In 

 other respects the difference between the immature and adult 

 bird is trifling, and in all points — such as the size and form of 

 the bill, talons, number of scales on the feet, &c. — they are the 

 same. Indeed, according to some ornithologists both the im- 

 mature and the adult birds breed, which may be perfectly true — 

 as a lad may have a wife without having his matured beard as 

 a man. In this alteration of feathers year by year, it is marvel- 

 lous in Nature thus to paint so correctly and so perfectly each 

 particular feather of each particular bird of each particular moult 

 to such exact similarity and likeness. After having had two 



