330 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. IX. 



sides; crissum, black, edged with white; central tail feathers, very 

 much elongated in the male ; feet, lead color. 



Length, 28; wing, 9.50; tail, 7; bill, 2. 



Adult female: Tail feathers, not so much elongated as in the male, 

 but broad and pointed; crown and sides of the head, streaked with 

 dusky and pale brown; breast, spotted with dark brown or black; 

 under parts, white; abdomen and sides showing faint lines of dusky; 

 under wing coverts, fuscous, edged with white; axillary plumes, 

 white, barred with dark brown; speculum, grayish brown, edged with 

 white. The immature male shows considerable variation in plumage, 

 the under parts being usually more streaked or spotted than the adult 

 female, which it otherwise somewhat resembles. 



Length, 22; wing, 9.25; tail, 3.50; bill, 2. 



This species is abundant during the migrations in Illinois and Wis- 

 consin, and is claimed to breed casually in Wisconsin and occasionally 

 in northern Illinois. The nest is of grass and sedge, sometimes lined 

 with feathers and down and often without. The eggs are 8 to 12, 

 pale buff white (sometimes showing a faint bluish tinge), and measure 

 about 2.25 x 1.50 inches. 



"Very abundant migrant and rare summer resident. * * * * 

 Every year a few pairs breed upon the marshes in this vicinity. 

 * * * * j n the spring of 1875, several pairs of these birds nested in 

 the prairie sloughs near the Calumet River, and on the 29th of May I 

 found a nest containing three freshly laid eggs." (Nelsons, Birds 

 N. E. Illinois, 1876, p. 139.) "An abundant migrant. A few still 

 nest within the state, but they are being gradually pushed further and 

 further north for the summer season." (Kumlien and Hollister, Birds 

 of Wisconsin, 1903, p. 20.) 



Genus AIX Boie. 



50. Aix sponsa (LINN.). 



WOOD DUCK. 



Local name: Summer Duck. 



Distr.: Temperate North America, breeding throughout its range 

 from Nova Scotia and southern British Columbia south to Cuba and 

 southern California (Mexico, one record from Mazatlan). 



Adult male: Bill, red, marked with rose-white, and a black stripe 

 on the middle of the upper mandible and tip; under mandible, black; 

 head, with decided crest which shows white, metallic green, and 

 purple; a narrow superciliary line from the bill to the occiput and 



