96 THE CHICAGO ACADEMY OF SCIENCES. 



our timbered regions. Mr. Robert Kennicott includes this species 

 in his list of Cook County birds,* with the following interesting 

 note: "In October, 1854, a flight of apparently several thousand 

 of this Hawk passed over Chicago from the Lakes, moving to- 

 wards the southwest." Mr. E. W. Nelson says:f "The main 

 fall migration of hawks in this vicinity takes place the last of 

 September or the first of October and a statement of the num- 

 bers which pass in a single day, to one who has not observed them, 

 would be received with incredulity. Choosing a day when there 

 is a strong south or southwest wind, the hawks commence moving 

 south early in the morning and continue flying the entire day, 

 and so numerously that, taking a stand at a good point, one 

 would have from one to fifty hawks in view, with but very few 

 intermissions, throughout the day. Among these occur all the 

 migrants, but by far the greater number consist of the smaller 

 species." At the present time the Red-shouldered Hawk is not 

 as abundant as it was in the days of Mr. Kennicott, nor are the 

 large flocks of hawks, of which Mr. Nelson speaks, to be seen 

 during their migrations, excepting on rare occasions. 



The range of this species includes eastern North America from 

 the southern portions of the British Possessions southward to the 

 Gulf States and eastern Mexico; westward to the Great Plains. 



Buteo swainsoni Bonaparte. Swainson's Hawk. 



Buteo awainsoni BONAPARTE, Geog. & Comp. List, 1838, 3. 



Popular synonyms : BBOWN HAWK. BLACK HAWK. CHICKEN HAWK. 



Swainson's Hawk is included in the fauna of our region be- 

 cause of a record published by Mr. E. W. Nelson,f who says. 

 "Of rather rare occurrence in this vicinity. Have only noted it 

 during the migrations. I obtained an immature specimen May 

 30, 1875, at Riverdale, Illinois, and have seen others since. As 

 this species breeds in southern Illinois it probably also breeds in 

 the northern portions of the state." 



The range of this species includes western North America 

 from Wisconsin, Illinois, Arkansas and Texas to the Pacific 

 coast, and from the Arctic regions on the north, south through 

 Central America and South America to the Argentine Republic. 



Buteo platypterus (Vieillot). Broad-winged Hawk. 



Falco latissimus WILSON, Amer. Orn., VI, 1812, 92, pi. 54, fig. 1. 

 Buteo latissimus SHABPE, Cat. B. Brit. Mus., I, 1874, 193. 



*Trans. 111. State Agri. Soc., 581, 1855. 



tBirds of Northeastern Illinois. Bull, of the Essex Institute, Vol. VIII, 1876, 119. 



