482 Field Museum of Natural History — Zoology, Vol. IX. 



American Sparrow' Hawk. 



Female. 



Male: Length, 8.60; wing, 6.60 to 8; tail, 4.40; tarsus, 1.35. 



Female: Length, 10 to 12; wing, 7 to 8.20; tail, about 4.50; 

 tarsus, 1.40. 



The Sparrow Hawk is a common summer resident in Illinois and 

 Wisconsin, arriving from the south in late March or early in April, and 

 leaving in October. The birds build no nest, the eggs being deposited 

 in hollow trees (sometimes deserted woodpeckers' holes) or occasion- 

 ally on a ledge of rocks. 



The eggs are five to seven, pale brownish or cream buff, blotched 

 and spotted with dark brown, varying from this to buff white or dull 

 white and showing a few faint spots of pale brown. They measure 

 about 1.30 X 1. 1 5 inches. 



The following sets of eggs from northern Illinois are contained in 

 the Field Museum collection: 4, Joliet, 111., May 16, 1906; 5, Lake 

 Forest, 111., May 23, 1906; 4, Joliet, 111., June 19, 1906. 



