JAN., 1909. BIRDS OF ILLINOIS AND WISCONSIN CORY. 455 



writers mention it as having been seen. If it occurs at all it is an 

 accidental straggler in Wisconsin. 



The nest is built in a tree. The eggs are three or four in number, 

 brownish white or whitish overlaid and mottled with madder brown, 

 and measure about 1.65 x 1.30 inches. 



Genus CIRCUS Lacepede. 



154. Circus hudsonius (LINN.). 

 MARSH HAWK. 



Distr. : North America, from Fur Countries to the Gulf, breeding 

 throughout its range; south in winter to Cuba and Central America. 



Special characters, adult male: General plumage, ashy gray; upper 

 tail coverts, white; belly and flanks, white, spotted with pale tawny 

 brown; wing, 13 to 15 inches; tail, over 8.25 inches. 



Female and immature male: Upper parts, brown, showing more 

 or less tawny rufous; upper tail coverts, white; under parts, tawny; 



Marsh Hawk. 



the belly and flanks, without bars or spots; wing, 13 to 16 inches; 

 tail, more than 8.25 inches long. 



The Marsh Hawk is a common summer resident in Illinois and 

 Wisconsin. It frequents the fields and open marshes and may be 

 recognized by its conspicuous white upper tail coverts. 



