RUDDT DUCK. 63 



Erismatura jamaicensis (Gmel. ). Ruddy Duck. 



Breeding range.— The principal summer home of the ruddy duck is 

 in the upper Mississippi Valley and the contiguous portions of central 

 Canada; it is rare east of the Alleghenies; breeds regularly from 

 Maine to northern Ungava; rare visitant in Newfoundland; nesting 

 rarety south to Massachusetts (Cape Cod) and probably in Rhode 

 Island (Sakonnet); tolerably common in southern Ontario, Michi- 

 gan, and Wisconsin, and probably breeds casually in Ohio and Illi- 

 nois. West of the Mississippi it breeds regularly to southern Min- 

 nesota and northwestern Nebraska and rarely in Kansas. The breed- 

 ing range then dips strongly to the south in the mountains through 

 Colorado to northern New Mexico (La Jara and Stinking Spring 

 lakes), central Arizona (Stoneman Lake, altitude 6,200 feet), southern 

 California (Los Angeles County), northern Lower California to about 

 latitude 31°, and probably northwestern Chihuahua (Pacheco). The 

 breeding range on the Pacific slope extends north at least to central 

 British Columbia (Cariboo District); in the interior to Great Slave 

 Lake and Hudson Baj r (York Factory). The above is the normal 

 breeding range, but this species has the peculiar habit of establishing 

 colonies far to the southward. Such colonies have been discovered at 

 Santiago, near the southern end of Lower California, in the Valley of 

 Mexico, at the Lake of Duenas, Guatemala, and on the islands of Cuba, 

 Porto Rico, and Carriacou. The breeding season of these isolated 

 colonies bears no relation to the usual breeding time in the bird's 

 ordinary range. In northern North Dakota the earliest eggs are 

 deposited the first week in June; in Manitoba and Saskatchewan incom- 

 plete sets were found the middle of June; the same date — the middle 

 of June — marks the deposition of the eggs in central Colorado. The 

 first half of June may be said to be the usual time for the beginning 

 of nesting. On Cape Cod, Massachusetts, downy young were taken 

 August 17; in northern New Mexico September 17; in southern Lower 

 California, November 16; at Lake Duenas, Guatemala, in June; while 

 in Cuba and Porto Rico eggs were taken in November, and on Carriacou 

 Island in January. 



Winter range. — In its choice of climate and environment the ruddy 

 duck varies widely. While many individuals retire in winter to the 

 southern part of the range, to southern Lower California, Tepic, Valley 

 of Mexico, Oaxaca, and central Guatemala, others remain as far north 

 as southern British Columbia. The northern limit in the Rocky 

 Mountain region is Arizona and New Mexico; the species does not 

 seem to remain through the winter in northern Texas, but at this 

 season it is found in southern Illinois, Pennsylvania, the coast of 

 Massachusetts, and even to Maine. During the winter the ruddy duck 

 has been recorded in the Bermudas, the Bahamas (New Providence), 

 4510— No. 26—06 5 



