618 REPORT OF STATE GEOLOGIST. 



*42. (149). Aythya affinis (EYT.). 



Lesser Scaup Duck. 

 Synonyms, LITTLE BLACK-HEAD, LITTLE BLUE-BILL. 



Similar to last species (A. marila nearctica), but smaller and flanks 

 waved or zigzagged with blackish. 



Adult Male. With head glossed with purplish instead of green. 



Length, 15.00-16.50; wing, 7.50-8.25 (7.81); bill, 1.58-1.90 (1.75); 

 greatest width of bill, .80-.95 (.89); least width, .60-.78 (.69). 



RANGE. North America, breeding chiefly north of United States, 

 rarely south of central Michigan, Iowa and Indiana. Winters from 

 Virginia and Gulf coast south to Guatemala and West Indies. 



Nest, on ground in swampy places, similar to last. Eggs, 6-10; color 

 same as last; 2.25 by 1.58. 



Very abundant migrant and rare summer resident. 



This is the most common of all our ducks. In April, October and 

 November the open lakes of northern Indiana are literally covered 

 with them. On Wolf Lake, Indiana, and Calumet Lake, Illinois, and 

 other small lakes of that vicinity at those seasons of the year, and 

 sometimes as early as March 20 (1886), in spring, they congregate by 

 thousands. They form the principal duck shooting in the vicinity of 

 Chicago, 



These ducks form a part of the second early migrants. They are 

 not so early as the Mallards and some other kinds, but follow promptly 

 after them. Some years they are noted the first week in March and 

 others the middle of that month. They remain through April, some 

 years into May, occasionally are seen in June. The following dates 

 will give some idea of its occurrence: At English Lake, first one 

 killed, 1886, March 14; 1887, March 9; 1889, March 14; 1892, March 

 6, first noted. (Deane.) 



In 1886, March 20, there were thousands at Wolf Lake. In 1896, 

 March 20, three were observed at Kouts. (Parker.) 



I have observed them at Brookville May 6 (1883). and Professors 

 Evermann and Blatchley noted it at Gosport, May 8, 1886. 



Mr. Euthven Deane informs me upon good authority that a pair of 

 Lesser Scaup Ducks, followed by a brood of young, were seen at English 

 Lake in June, 1886. One or both of them were supposed to be 

 "cripples." Mr. W. H. Collins found a nest of this species at St. Clair 

 Flats, Mich. (B. K 0. C.; V., p. 61.) 



They seem- to pair late. Early in May they begin to be observed in 

 pairs, and by the middle of the month most of those that are found 



