JAN., 1909. BIRDS OF ILLINOIS AND WISCONSIN CORY. 465 



Red-shouldered Hawk (adult). 



Male: Length, 18 to 20.50; wing, 11.60 to 13.25; tail, 7 to 8.50; 

 tarsus, 2.75 to 3.10. 



Female: Length, 19.50 to 22.50; wing, 12 to 14.25; tail, 8.25 to 

 9.25; tarsus, 3.00 to 3.25. 



The Red-shouldered Hawk is a common summer resident in Illinois 

 and not uncommon in Wisconsin. The immature birds somewhat 

 resemble those of B. borealis, but besides other differences they are 

 smaller and the tarsus more slender and less feathered than in that 

 species. 



Usually nests in a large tree. The eggs are 3 to 5, rarely six, 

 dull white, spotted and marked various shades of brown. They 

 measure about 2.10 x 1.70 inches. Incubation usually commences in 

 late April or May in this latitude. 



160. Buteo swainsoni BONAP. 

 SWAINSON'S HAWK. 



Distr.: Ranges from Wisconsin, Illinois and Mississippi Valley 

 west to the Pacific Ocean, and from the Fur Countries south to South 



