The Surf-Scoter 
77 
above, below, and in front of the orange area all round the nostrils. These black markings 
continue until the bird is quite adult (twenty-six to twenty-eight months). All through the 
winter the black adult plumage pushes in and displaces the first plumage, until by May the 
bird has cast all signs of immaturity except the wings, tail, and small areas of feathers on 
the back and lower breast. As is the case with so many diving ducks, there is a great 
disparity in the plumage of early and late hatched young birds. One young bird killed 
on May i has the whole of the under parts, mantle, wings, tail, and white patch in front of 
the eye still unmoulted ; whilst another, killed on the same day, has a new black tail and all 
the rest of the plumage black except the wings and a small area of immature feathers on the 
back and breast, the latter having faded to pure white. All these young birds seem to get 
the snow-white patch at the back of the head ; but instead of the white patch on the crown, 
they have a black one. It is probable that the young males at twelve months get a few 
eclipse white and brown feathers between the eye and the bill whilst the main moult is 
proceeding towards the first full plumage, but I have seen no specimens killed at this date. 
In the following November the young male Surf-Scoter attains his full dress, except 
that there is a brown edging to white patch on the crown, and the bill has a black band 
on the upper surface, down the nail and forward from the square black patch on the sides 
of the upper mandible. These signs of immaturity do not disappear until the following 
August, when the bird moults to his first adult plumage and gets the full-coloured bill, for 
a bird in my possession, killed only in May near Vancouver Island, has these immature 
features clearly defined. The male Surf-Scoter therefore attains full maturity at twenty- 
seven or twenty-eight months. 
Adult Male. — The whole of the plumage is a deep glossy black, except a large pure 
white patch on the centre of the crown and another on the hind neck ; the bill is of a 
peculiar shape. There is a large lump on each side of the base, where there is a square 
patch of black ; above the black patch it is orange, passing to vermilion at the back ; pure 
white below until it reaches a line below the nostrils ; above the nostril to the front of the 
crown it is deep red, which extends forward and fades into the pale yellow of the nail. 
Behind the nail and the front and below the nostrils the colour is orange. Irides white ; 
legs dull pinkish red and dark orange on the sides of the toes ; a line of dusky black extends 
down the central toe, and the joints are black ; webs dusky black. Length, 20 to 21 inches ; 
wing, 9.6 inches ; tarsus, 1.8 inch. I have not seen a specimen killed in July or August, but 
the Surf-Scoter probably follows the other members of the genus in having a few eclipse 
brown and whitish feathers in front of the eye whilst the principal moult is proceeding. 
Immature Female. — The young female at first resembles the young male; but in 
November can easily be distinguished by the shape and colour of the bill and the advanced 
plumage of the respective sexes asserting itself. The moult follows the same course as the 
male, the young females being half changed by April, and retain their immature lower breasts, 
wings, tail, and portions of the back until the principal moult in August. In October the 
full plumage is gained, but it is not known yet if these females are sufficiently mature to 
breed in the following spring. Since the males are not adult until twenty-seven to twenty- 
eight months, it is probable that females are similar to female Eiders, and do not breed until 
thirty-four months. 
Adult Female. — Crown blackish-brown; a small or fairly large triangular patch of 
