LESSES SCAUP DUCK 161 



The Lesser Scaup Duck or Little Blue-bill is the commonest duck 

 found on the salt water bays and marshes along the coast during the 

 winter season. Kafts of Lesser Scaups are always to be found on 

 San Francisco and San Pablo bays from October to April, and this 

 is the duck most commonly seen resting on the water near the ferry 

 moles or diving for mussels about the piling. Non-breeders are occa- 

 sionally seen in California during the summer. They have been noted 

 in June at Santa Barbara (Torrey, 1910?), p. 204). Even as far 

 south as San Diego large flocks have been known to remain until the 

 first of May and individuals were seen there as late as May 7, 1885 

 (Belding, MS). In 1881 Lesser Scaups were seen in the markets of 

 Stockton as early as October 6. On San Francisco Bay E. W. Gifford 

 (MS) has record of "Blue-bills" as follows: 1904-1905: first seen, 

 November 23 ; last seen. May 13 ; 1906-1907 : first seen, November 29 ; 

 last seen, April 14 ; 1907-1908 : last seen, May 20 ; 1908-1909 : first seen, 

 December 25 ; last seen, March 21 ; 1909-1910 : first seen, November 7 ; 

 last seen, February 28. They apparently foUow the coast more gen- 

 erally in their southward migration, and the interior in their northward 

 migration; practically all of the records from the interior are in the 

 spring. Inland this duck is found chiefly on the larger bodies of water. 



The breeding range of the Lesser Scaup is a little more southerly 

 than that of the Greater Scaup, as Nelson and others have not found 

 it in northern Alaska. The southern limit of its summer range is 

 certainly far south of that of the Greater Scaup. The great interior 

 plains region, from northern North Dakota and northern Montana 

 to the edge of the timber near the Arctic coast in the Anderson and 

 Mackenzie river regions, contains the principal breeding grounds. 

 The migration carries most of these breeders southeast to the south 

 Atlantic states and even to the Bahamas and Mexico. The birds found 

 along the Pacific coast are thought to breed mostly in the interior of 

 British Columbia, Alaska, and Yukon territory. 



As has been noted in the discussion of the Greater Scaup Duck the 

 Lesser Scaup is practically indistinguishable from it at a distance of 

 more than a few yards in spite of the fact that some observers claim 

 to have noticed differences in habits. A Scaup is readily recognized 

 from other ducks by the combination of black head, blue bill, white 

 or light mantle and white speculum and belly (pi. 5). On close 

 examination the male Lesser Scaup can be identified and separated 

 from the Greater Scaup by the presence of a purplish instead of 

 greenish gloss on the head, by lack of whitish on outer webs of inner- 

 most primaries, and by heavier markings on the scapulars and fianks. 

 But size is the main distinguishing feature, and females can nearly 

 always be separated by this character if by no other. The Lesser 

 Scaup averages nearly two inches less in total length and the folded 

 wing is about an inch shorter. 



