CANVASBACK. 43 



about as far north as the species occurs regularly in large numbers, 

 the course is almost at right angles to the general trend of the 

 Atlantic coast line. In other words, this is the course the redhead 

 should take to reach salt water by the shortest route. This route 

 from Manitoba to Long Island is through a district abounding in 

 shallow lakes and marshes, which furnish abundant food. After 

 reaching the coast, most of the redheads pass southward and winter 

 from Chesapeake Bay to Florida and the Bahamas. Only a portion of 

 the species, however, takes this east and west course. Many flocks pass 

 directly south and are common all through the Mississippi Valley to 

 the Gulf coast and through Texas to central Mexico. The average 

 date when the first migrants appear in southern Ontario is September 

 19 (earliest September 10, 1896); at Erie, Pa., the average date is 

 October 7, while at Alexandria, Va. , a long series of careful records 

 fixes October 12 as the average date of arrival — October 5 (1901) the 

 earliest — and October 29 as the average date when the species becomes 

 common. In general it may be said that the large flocks cross into 

 North Dakota about the 1st of October, are common in the central 

 Mississippi Valley about the middle of the month, and reach the Gulf 

 coast, from Texas to Florida, early in November, when the last are 

 deserting the northern breeding grounds. 



A single individual was seen in southeastern Labrador, September 

 23, and this bird must have journeyed nearly 2,000 miles in a due 

 easterly direction. 



Aythya vallisneria (Wils. ). Canvasback. 



Breeding range. — The district just east of the Rocky Mountains in 

 Alberta seems to be a center of abundance of this species in the 

 breeding season. East of this district it breeds commonly to about 

 the one hundredth meridian; south to the southern boundary of 

 Canada, west to central British Columbia and Sitka, north to Great 

 Slave Lake, and northwest to Gens de large Mountains and Fort 

 Yukon. It does not commonly breed in the United States, but a few 

 nest in northern North Dakota and in diminishing numbers southward 

 to Nebraska (Cody, Irwin, Hackberry Lake); it is rare as a breeder in 

 Minnesota (Madison, Heron Lake), and a few crippled birds have been 

 known to breed on Lake Koshkonong, Wisconsin. In 1900 it bred 

 casually at Barr Lake, near Denver, Colo., and it has been known to 

 breed at Pyramid Lake, Nevada, and in a few places in Oregon. 



Winter range. — The statements of the breeding range just made 

 show that the eastern edge of the regular summer home is more than 

 a thousand miles west of Chesapeake Bay, which, until a comparatively 

 recent period, was a favorite winter home for the canvasback. The 

 line of the Great Lakes seems to be the general route followed in this 

 southeastward migration, and a few canvas backs stop for the "winter 



