272 BAY, SEA OR DIVING DUCKS 



groups of the species. The wings of the Barrow's whistle in flight as do 

 those of the Whistler but possibly the sound is neither quite so loud nor 

 so metallic. The flight is similar and the flocks usually do not consist of 

 more than a dozen birds, except in the mating season. An outstanding 

 difference in the behaviour of the two species is that the Barrow's are 

 comparatively tame and trusting birds which come unhesitatingly to de- 

 coys and seem to show little fear of man. This is probably due to the 

 fact that they are less sought by gunners. The anatomical differences 

 between the two species are given under the head "Specimen Identifica- 

 tion of the American Golden-eye. 



In spring the groups that winter on the Pacific and Atlantic coasts 

 begin their short voyage to their respective breeding grounds as early as 

 weather permits. Those that have wintered on the Pacific coast move to 

 the Rocky Mountain district and those from the Atlantic coast to the 

 Labrador Peninsula. This species is much more common in the West, 

 and the majority spend the summer on a breeding range that lies mainly 

 in and around the Rocky Mountains. The migration in the autumn is 

 so short that it is merely a shift from the more northern part of their 

 range to the southern and towards the coasts; the movement takes place 

 during October and November. In the winter those that breed north of 

 the St. Lawrence shift to the Gulf of St. Lawrence and as far south as 

 the coast of Maine. On the Pacific coast they winter as far south as 

 central California and a few winter on the Okanogan, Gardiner, and 

 Yellowstone Rivers. 



