The Common Scoter 
53 
brown with greyish-white edges ; under parts the same, but with broader white margins ; 
thighs and vent brown ; rump, blackish-brown ; nape, scapulars, mantle, dark brown with 
more or less light edges ; wings brown, with the secondaries almost black with light edges ; 
primaries blackish-brown ; tail brown. In late November the jet-black feathers begin to 
come in generally on the throat, cheeks, and under tail-coverts, whilst in the following 
month patches of black feathers may appear on the breast. (In many cases the greater part 
of this moult is not acquired until March.) The advance in plumage is very slow in the 
three following months, when a few more patches of black may be attained by April. In 
very advanced young males the whole of the black plumage may be assumed by April, 
except on the long scapulars, wings, tail and rump, and under parts, which always appear to 
be retained in first plumage until the principal moult in July and August. Usually young 
males retain a considerable portion of their first plumage on the cheeks, neck, and under 
parts until July, and these feathers fade almost to white in that month. Throughout the 
winter and spring the knob on the bill develops, and the area of yellow extends in size and 
becomes richer in colour, so that by April this feature of the bird is sometimes almost 
as complete as in the adult, in form but not in colour. This, however, is unusual, for a 
young male in my collection, killed in August at Filey, Yorks, has the bill only half 
developed, whilst two specimens living in the Zoological Gardens, July 19 12, were similarly 
incomplete. 
The principal moult towards maturity commences in July, when the bird is one year 
old. A number of temporary brown feathers, which may be called the first eclipse, appear 
on the head and neck, these being again shed in late October. The main parts of the 
plumage, such as the upper and lower parts, rump, and tail, are now shed, all immature 
feathers being replaced by glossy black ones. The wings do not seem to be shed until the 
end of August (a specimen killed on August 10 still showing a faded-white breast and first 
plumage wings). 
In October the head and neck and flanks moult the brown feathers of the first eclipse, 
and the bird attains its full plumage by the middle of November — that is, at 164- months — but 
it can always be identified by the colour of the bill until 21 to 24 months. These young males 
are never so bright in their plumage, nor are the central tail feathers so long and pointed, as 
older males, nor do I think any of them breed in the following spring. In all the winter 
resorts numbers of "black" males are still to be observed throughout the spring and 
summer, when nearly all the adults have departed for more northerly regions, and there are, 
I think, males which have attained full plumage but cannot nevertheless be considered quite 
adult. The same remark may be applied to both the other species of Scoter. 
Two males (aged 21 months) killed on March 27, 191 3, by the Honourable Gerald 
Legge, at Patshull Mere, near Wolverhampton, were in plumage adult, but the bills 
were still incomplete, both in form and colour. One of these had nearly lost all the 
reddish-yellow in the dip between the knobs of the upper mandible, but the other had 
still the narrow band and broader expanse of cadmium-orange seen in October birds 
(see figures, coloured plate of Scoters). In the case of the first or slightly more advanced 
bird, the bill would doubtless have acquired its full shape and beauty in the course of 
the next two months. It can therefore be said that the male Common Scoter acquires 
maturity at from 23 to 24 months. The weight of these two birds were each i lb. 14 oz. 
