THE GYR-FALCON, 



101 





6 



Key to species of genus Falco. 

 Larger, wingo* over 345, <j> over 380 mm. 

 Smaller, wingo* under 345, 2 under 380 mm. 2 



Back rufous 3 



Back grey or brown .... 4 



1st primary much longer than 4th ... F, naumanni, 



1st primary about equal to 4th ... F. tinnunculus, 



Middle toe without claw over 40, culmen 



over 17 mm 



Middle toe without claw under 40, culmen 



notover 17 mm 5 



Middle toe without claw over 30 mm. . 6 



Middle toe without claw under 30 mm. . . F. vespertinus , 



Tail grey with wide subterminal black bar, 



back bluish-grey with obvious black shaft- 

 stripes F. c. cesalon, <$ ad., 



Tail grey without wide subterminal black 



bar, back uniform grey, not obviously 



striated with black F. subbuteo, ad., 



Tail brown with rufous bars, feathers of 



back and scapulars with buff or rusty 



edges F. subbuteo, juv., 



Tail brown with light bars, feathers of back 



and scapulars barred or spotted with 



rufous F. c. cesalon, $ ad. and juv. ? 



F. rusticolus, p. 101 



p. 124 

 p. 119 



F. peregrinus, p. 107 



p. 127 

 p. 115 

 p. 113 

 p. 114 

 p. 116 



FALCO RUSTICOLUS* 



242. Falco rusticolus rusticolus L. — THE GYR-FALCON. 



Falco rusticolus Linnaeus, Syst. Nat., ed. x, i, p. 88 (1758 — Sweden. 

 cf. Fauna Suecica, ed. 11, p. 19, No. 56). 

 Falco gyrfalco Linnaeus, Saunders, p. 345. 



Description. 

 — Adult male and 

 female. Winter 

 and summer. — 

 Fore -head white, 

 fi n e 1 y streaked 

 black ; crown dark 

 slat e-brow n , 

 feathers with 

 blackish shaft- 

 streaks ; feathers 

 over eyes and 

 down sides of back 

 of crown with nar- 

 row, and feathers 

 of nape with wider, buffish-white edgings 



The Gyr-Falcon (Falco r. rusticolus). 



feathers of mantle and 



* It seems impossible to avoid this name, for gyrfalco is undoubtedly a 

 synonym, both names referring to Swedish birds in various plumages. — E.H 



