lo British Diving Ducks 
Adult Eclipse-phimage. — In May the males have lost the full beauty of their plumage, 
the upper-breast feathers become dull, the bird loses the fine yellow tint on the scapulars, 
and the rich green on the head fades, and by June the sickle-feathers are worn and abraded. 
Sometimes as early as June 23, and more generally about July 1-4, the eclipse- 
plumage of the adult male begins to appear on the neck and mantle. Some birds change 
the bright parts of the plumage, such as the head, neck, upper-breast, back and upper 
scapulars, in a week, the rest of the moult — which embraces the lower-parts, wings, inner- 
secondaries, tail-coverts, and tail — are then slowly changed only once into direct winter- 
plumage. The bird may be said to be in full eclipse about August 5, when it has a very 
" black " appearance on the water. 
Head and neck, except for a very small space of grey and black feathers over the eye, 
black with upper parts of the feathers brown ; nape, mantle, and scapulars black ; sometimes 
the black feathers in the centre of the back are finely edged with white, but this wears off 
in October ; wings and tail as in winter ; upper-breast white barred with black and edged 
with reddish-brown ; rest of under-parts black as in winter. 
Note. — Some examples are not so dark as above described and have the chin and 
throat suffused with grey ; others never completely lose the white feathers on the nape, but 
renew in September directly into white again. I do not feel certain as to what extent the 
feathers on the upper-breast are changed, and think this region is shed differently according 
to individuals, some taking on temporary eclipse-feathers, and others only renewing once 
between July i and October i. I think, however, the region nearest to the neck is 
generally renewed twice, and that nearest to the lower-breast and belly only once, because 
we find males in every degree of feather " wearing " from October i to the end of 
November. The black-edged feathers in October and November are not shed again during 
these months to pure buff ones, but wear the black edges away. 
Briefly, to summarise the plumages of the male Eider, the duckling passes from the 
down-state to juvenile-plumage, which it only retains in part, varying greatly in individuals, 
for a short time. The speckled " first winter-plumage is attained through the first winter 
and early spring. The juvenile wing, sometimes the tail, and more rarely the lower-parts, 
are retained for a whole year. At 12 months the greater part of the first eclipse- 
plumage is assumed, and this again is soon moulted with the parts of the plumage that 
only change once a year. From 15-18 months the second winter-plumage is gained, and 
the bird is like the adult male except for the pied fore-wing and the black-edged curled 
secondaries. This plumage is kept until 24 months, when the second eclipse is assumed. 
At 27 months the third winter is in full progress, and the bird attains adult plumage with 
perfect white fore-wing and curled secondaries at 28-30 months. 
The male therefore goes through one complete moult every year, in which the moulting 
of the head, neck, upper-breast, and back are renewed twice, and the wings, tail, long 
secondaries, upper and under tail-coverts only once. 
There is not the least doubt that, as Mr. Schioler points out, the male bird becomes 
more brilliant in plumage and more massive in skeleton in the fourth spring, but to all 
intents and purposes it is adult at 28-30 months, and will pair and breed in the following 
spring. It may be possible that the immature male may pair and breed in its second year, 
though we have no conclusive proof that it does so, for it is usual to see these immature 
