84 
BIRD-LIFE. 
young bird acquires the full plumage of the old one at the 
first moult, it may he justly regarded as a complete adult 
bird, and in a condition to propagate its species. With 
the Raptores and aquatic birds, whose developement is not 
so rapid, we use the term—birds of the first, second, 
third and fourth year, to distinguish them from the 
full-grown bird. Other changes take place, which are, 
more or less, intimately connected with the casting 
of the plumage; the beak, feet and iris being often 
subject to great alterations in colour. A muster of our 
best-known birds will show the great gaps incidental to 
some families and species during their progress to 
maturity. The larger Raptores cast their downy covering 
in the nest, quitting the latter in their youthful dress, of 
which generally not one feather is cast before the year is 
over: the smaller species of this family only change the 
lesser body-feathers at the first moult. It has, as yet, not 
been determined with certainty what period of time 
elapses before Eagles and Vultures assume the final 
adult plumage. Faber knew of an instance in which a 
Sea Eagle taken from the nest had not, after a period of 
ten years, donned the white tail, the sign of its having 
reached maturity. I have seen a specimen of the King of 
the Vultures (Gyparchus Papa), whose adult plumage was 
only assumed after six years’ captivity in Europe, added 
to which it is very possible that the bird had passed some 
years in freedom in America. All the nocturnal birds of 
prey leave the nest in a spotted dress of down, receiving, 
little by little, the adult plumage, and this, by the first 
autumn—after which but little change takes place, save 
that the whole plumage increases in beauty with each 
succeeding year. The same may be said of most 
other birds, though, with many of them, a peculiar 
