140 



species is frequently seen during winter flying about 

 extensive meadows near Norway, but they are very shy 

 and watchful and I have never been able to procure a 

 specimen. 



F. SPARVERius, Linn. Sparroiv Hawk. Spring and fall. 

 Not very common. This species possibly breeds at Nor- 

 way although I have never seen it there in summer. 



AsTUR ATRICAPILLUS, Bon. Gosliaivk, " Blue Hawk.'" Res- 

 ident. Common. Breeds. This is one of our most com- 

 mon hawks. When in the brown immature plumage it is 

 usually confounded under the name of " Hen Hawk," 

 with Buteo borealis and B. lineatus. It may always be 

 distinguished readily from either, by its more slender 

 form, relatively longer legs and tail, and shorter wings. 



AcciPiTER CooPERii, Bou. Cooper's Hawk. Summer vis- 

 itant. Not common. 



A. FUSCTJS, Bon. Sharp-shinned Haivh. Summer visitant, 

 very common. Breeds. Arrives the last of March or 

 first of April. The young are fully grown by the first 

 of August. 



Buteo borealis, Vieill. Red-tailed Hawk. " Hen Hawk.^"* 

 Summer visitant. Common. Breeds. Arrives about the 

 middle of March. The eggs are laid about the middle of 

 April. 



B. lineatus, Jard. Red-shouldered Haiuh. Summer vis" 

 itant. Not very common. Breeds. The only eggs o^ 

 this species that I have obtained at Norway were 

 collected May 24th, 1860. The differences in size 

 between specimens referred to this species from Florida, 

 and those from Maine and other parts of New England, 

 are very great, and may indicate a specific difference, 

 although there is little or no difference in color. Nor 

 would this be the only instance in this family where 

 species, recognized as distinct, difier in no important 

 character except size. This is particularly the case in the 

 three North American species of Accipiter. I give below 

 a table of comparative measurements taken from speci- 

 mens in the Museum of Comparative Zoology at Cam- 

 bridge, except the last one which is copied from meas- 

 urements given in the General Report on the Birds of 

 North America, 



