LIFE HISTORIES OF NORTH AMERICAN WILD FOWL 141 



in the beds of shellfish which abound in this region. Great rafts 

 of them may be seen bedded on the water way offshore where they 

 sleep and rest. At certain stages of the tides, when the water is not 

 too deep over their feeding grounds, they fly in regularly, day after 

 day, to the same spot to feed on the mussel beds on the submerged 

 ledges and sunken rocks along the shores and even in the harbors. 

 Scallop fishermen are often guided b}^ their movements in locat- 

 ing their quarr3\ Gunners soon learn to locate their feeding grounds 

 and take advantage of their regular flights. 



"Winthrop Sprague Brooks (1915) described, under the sub- 

 specific name, dixoni^ a subspecies of the white-winged scoter, the 

 type of which was collected by Joseph Dixon at Humphrey Point, 

 Alaska. He assumes that all of the white-winged scoters, which 

 breed in Alaska and migrate down the Pacific coast, are referable 

 to this subspecies, which he characterizes as " similar to degJandi^ 

 with the exception of the size and shape of bill, which in dixoni is 

 shorter and broader in proportion to its length and more blunt at 

 the tip, with the angles from its greatest width to the tip more 

 abrupt." He says further : " On examining a large series of white- 

 winged scoters from both sides of the continent there is no diffi- 

 culty in separating Atlantic and Pacific birds by means of this 

 character of the bill." 



In order to establish a winter range for this subspecies I wrote 

 Dr. Joseph Grinnell for his opinion on the status of California 

 birds. He replied as follows : 



I know nothing about Oidcmia dcfflandi dixoni. I have not used this name 

 for any of the birds in this museum, because the authenticity of the alleged 

 race has not been verified by anyone else. I have just looked at our birds, 

 with Brooks's drawings of bills before me. I see every sort of variation from 

 the narrow extreme to the broad extreme among birds taken in California. 

 There are only three eastern birds here, and each of them finds a counter- 

 part among California-taken specimens. 



From this statement I should infer that the subspecies is unten- 

 able and that the characters ascribed to it are due to individual 

 variation. The study of more specimens from the supposed breeding 

 range of dixoni might establish a local breeding race, which mingles 

 in its winter range Avith the commoner form. A careful study of a 

 large series from many localities is necessary to settle the question. 



Dr. H. C. Oberholser and I have recently made a careful study 

 of the large series of white-wingecl scoters in the collections of the 

 United States Xational Museum and the Biological Survey, con- 

 taining birds from many different parts of North America, and find 

 that the characters on which dixoni are supposed to be based can 

 be matched in many birds from the Atlantic coast, and that they 

 are no more prevalent in birds from the Pacific coast or the interior 



