14 A NATURAL HISTORY OF THE DUCKS 



land. Teal banded in Denmark spread out later to southwestern England, Ireland, 

 the west coast of France, Holland, southern Spain, and northern Italy. A European 

 Widgeon banded in England in 1915 was taken on the north coast of the Caspian Sea 

 in 1918, which shows a very remarkable east and west dispersal. 



Most interesting, too, is the distribution of the sexes in migration. The true geese 

 migrate in pairs and families. Not so with the ducks, for it is quite certain that 

 among most of our common ducks the females and young start first and go farther, 

 while the males come later, and these males may even stay in a more northerly win- 

 ter area. This applies also to the Mergansers. On the other hand, the old males of 

 the Scoters migrate very early, even in July and August, although they do not neces- 

 sarily go farther south. In some cases, at least, with birds of this genus (Oidemia), 

 the females and young, who come later, pass the males and winter south of them. 

 With the Barrow's Golden-eye, the males disappear entirely as soon as the females 

 lay their eggs, and leave the mountain streams of British Columbia for regions un- 

 known. In a great many of the surface-feeding ducks the males assemble at certain 

 points and begin to moult as soon as incubation has begun. 



Then there is another phase of this most interesting subject. In a given locality 

 there may be individuals of a certain species that are sedentary, and others that 

 arrive from distant breeding-grounds in the winter to swell the ranks. Or it may be 

 that locally bred ducks depart before their northern-bred brothers arrive, as we see 

 in the case of our own Black Ducks. We may even picture to ourselves cases in which 

 breeding groups from different localities are continually overlapping each other on 

 migration, no one group moving very far in a southerly or northerly direction, al- 

 though the movement of the species as a whole may be considerable. Again, it is by 

 no means sure that a northern-bred group within a species will move only a short 

 distance to the south. I am quite certain that our northern- and western-bred Black 

 Ducks, the so-called Red-legs, actually are found farther to the south in winter than 

 the ducks bred along the coast of New England and the Gulf of St. Lawrence. 



Certain well-favored spots, which are cool enough for nesting, and yet have open 

 water in winter, harbor small sedentary groups within a species. Thus Mallards, 

 and apparently the same individuals, remain throughout the year in certain parts of 

 Alaska and our Rocky Mountains. In North America many ducks are forced to 

 travel two or three thousand miles, from the Athabasca Delta to North Carolina, 

 let us say; but in western Europe, on account of a more uniform climate, warmer 

 winters and cooler summers, there is no necessity for so extended a journey, and we 

 find a tendency to shorter migrations, and more sedentary groups within the species. 

 v The Mallard is as good an example as any. As we move farther east, however, we 

 reach countries where there are very cold winters and hot summers and conditions 

 are more like those in North America. 



Young Mallards bred in England have been extensively banded there; many of 



