CUCKOO. 385 
the sexes is much greater; the male loses nearly all the chestnut on his 
plumage, but retains the white edges to the feathers, whilst the female 
moults into what is called the “hepatic” stage, in which the chestnut is 
increased -in brilliancy and the white edges to the feathers disappear. 
These females just entering their second year do not breed, and seldom 
migrate far north—a fact which may be observed in many other species. 
In the following autumn both male and female assume nearly adult 
plumage, traces of immaturity being still found, especially in the female, 
on the breast and back. The fully adult plumage is assumed in the 
following spring, when the bird is scarcely two years old. In this plumage 
the general colour of the upper parts is slate-grey, browner on the wings, 
which are barred on the inside webs with white, and nearly black on the 
tail, which is broadly tipped with white and shows obscure traces of white 
bars, which, however, are often absent on the centre feathers. The general 
colour of the underparts above the breast is pale slate-grey, and below 
greyish white, with dark-brown transverse bars, which become very indis- 
tinct on the under tail-coverts. In immature birds the chin and throat 
are barred like the breast. Bill slaty black, paler at the base and yellow 
at the edges; legs, feet, and claws orange-yellow; orbits and irides yellow, 
In the fully adult plumage the sexes are alike in colour, 
VOL. TI. 2¢ 
