AMERICAN MERGANSER. 19 



The material for determining- the geographic rang-e cf the water- 

 fowl included in this bulletin has been derived from various publica- 

 tions, from museum specimens, and from the notes of field agents of 

 the Biological Surve3^ The data on migration are derived "almost 

 entirely from the migration schedules contributed since 1884 to this 

 Bureau by hundreds of observers distril)uted throughout the United 

 States and Canada. Opportunity is here taken to extend acknowl- 

 edgments to the many whose painstaking observations for a long series 

 of years have made possible the present publication. 



DISTRIBUTION AND MIGRATION OF DUCKS. 



Merganser americanus (Cass.). American Merganser. 



Breeding range. — The principal In-eeding- ground of this merganser 

 is in southern Canada from the maritime provinces to Saskatchewan. 

 Southward the species nests quite commonly in Maine, the colder 

 portions of New Plampshire, and in Vermont; it probably has bred 

 casually or accidentally in Massachusetts. It is rather common in the 

 Adirondacks and is not rare in the lake region of northwestern New 

 York. It formerly bred in several of the mountainous counties of 

 central Pennsylvania (Perry, Lancaster, Clinton, and Lycoming), and 

 may yet breed occasionally in that State and in Ohio. It breeds com- 

 monly at Ottawa and the Muskoka region in Ontario and it is not rare 

 in the southern part of the Province and on the shores and islands 

 of Lake Ontario. It is common in northern Michigan — rarely ay far 

 south as central Michigan — also in southwestern Minnesota (Heron 

 Lake), South Dakota (Fort Sisseton, Black Hills), and south in the 

 Rocky Mountains to northern New Mexico (near Santa Fe), north 

 central Arizona (Fort Verde), and the Sierras of California. 



The breeding range extends north to central Ungava (Hamilton 

 River), Hudson Bay (York F'actory), Great Slave Lake, and on the 

 Pacific coast regularly to the Queen Charlotte Islands, and rarely to 

 the base of the Alaskan Peninsula at about latitude 60° (lak Lake, 

 July 21, 1896). 



Winter range. — On the Atlantic coast this duck ranges from Maine 

 to South Carolina, rarely to Georgia and Florida; in mild winters it 

 occurs as far north as Prince Pxlward Ishmd; in the interior it winters 

 from the Gulf of Mexico to southern Ontario, Lake Michigan, Kansas, 

 northern Colorado, Idaho, British Columl)ia, and rarely to Unalaska 

 Island and the Pribilof Islands. In winter it reaches northern 

 Mexico, and northern Lower California. It occurs occasionally in 

 the Bermudas. 



Spring migration. — Though the northward movement of this mer- 

 ganser begins early— late February— and there is much activity in the 

 Mississippi Valley in March, on the Atlantic coast the advance beyond 

 the usual winter home is comparatively late. The average date of 



