obb Brooks, Notes on American Ducks. [ j^y 



In flight the silvery under-surface of the primaries, in both 

 sexes, is very conspicuous. In fine calm weather they call a 

 great deal and their plaintive 'cour-loo' is the most musical of 

 duck-cries, very different from the croaking notes of most diving 

 ducks. While very strongly opposed to multiplying genera, I 

 must agree with Dr. Dwight that this Scoter is hardly con-generic 

 with the other two American species, this difference is most pro- 

 nounced in its actions. 



Oidemia deglandi. White-winged Scoter. 



This duck throws a good deal of light on the movements of 

 many of the sea-ducks, as its migrations are largely made by 

 daylight. The northward movement is en masse in May and 

 very early June, and a large proportion of the flocks migrate 

 diagonally across country in a northeasterly direction. I think 

 the bulk of the Mackenzie River Valley birds migrate across 

 British Columbia. The sexes in the flocks at this time seem to 

 be proportionate. 



A few birds of all ages remain on the coast all through the 

 summer — now breeding adults and young birds of the preceding 

 year. Late in July and early in August small flocks of adult 

 males return by the same route, and passing down the inland 

 lakes they arrive on the coast and form very large flocks. As 

 Dr. Dwight has recorded there is no eclipse in the Scoters, these 

 birds are all in worn plumage. 



Early in October comes the great migration of the females and 

 young, these are usually in small lots of eight to a dozen — evi- 

 dently the female with her brood. 



They frequently remain on the inland lakes for a few days, 

 forming larger flocks, and then pass on to the coast, a few adult 

 males are with them. None breed in southern British Columbia. 



Oidemia perspicillata. Surf Scoter. 



While this is not an exclusively maritime duck, like the Amer- 

 ican Scoter is with us, its migrations, while generally similar to 

 those of the Wliite-winged Scoter, are much more coastwise. A 

 few, both adults and young, on both the Spring and Fall migra- 

 tions, migrate across country, but for the real movement one 

 should be about a mile off shore on the salt water. 



