BIRDS OF NORTH AND MIDDLE AMERICA 715 



(crit.). — Alcorn, Condor, xlviii, 1946, 132 (Lahontan Valley, Nev.). — 



MuNRO, Condor, xlviii, 1946, 182, in text (Redstone, w. of Williams Lake, 



Brit. Columbia). 

 Falco suckleyi Shabpe, Hand-list, 1, 1899, 275. 

 Falco lithofalco sxickleyi Ridgwat, in Baird Brewer, and Ridgwaj^ Hist. North 



Amer. Birds, iii, 1874, 143.— Goode, U. S. Nat. Mus. Bull. 20, 1883, 320. 

 Aesalon lithofalco suckleyi Goode, U. S. Nat. Mus. Bull. 20, 1883, 305. 

 Aesalon columbarius suckleyi Ridgwat. Proc. U. S. Nat. Mus., iii, 1880, 192; 



Norn. North Amer. Birds, 1881, No. 417a). 

 Aesalon columlarius subspecies b. suckleyi Gurnet, List Diurn. Birds Prej', 



1884, 104 (crit.). 

 Aesalon suckleyi Gurnet, Cat. Birds Prey, 1894, 29. 

 Tinnunculus columbarius suckleyi Oberholser, Auk, xxxv, 1918, 207.— Willbtt, 



Pacific Coast Avif., No. 21, 1933, 47 (syn.), 

 Falco aesalon Hall, Murrelet, xix, 1938, 7, footnote (Columbia Puver, Wash.; 



spec.;. 



Subgenus Tinnunculus Vieillot 



Small, rather slender falcons (wing about 166-279 mm.) with 

 inner toe, without claw, extending beyond penultimate articulation 

 of middle toe; middle toe, with claw, decidedly shorter than tarsus; 

 hallux, without claw, less than one-third as long as tarsus; tail two- 

 thirds as long as wing, rounded, two outer primaries with inner 

 webs emarginated, sexes conspicuously unlike in color (in all stages) 

 and young similar to adults in coloration. 



Bill relatively rather small, but strong, its depth at base of rham- 

 photheca decidedlj^ exceeding its width at same point and very nearly 

 equal to distance from anterior margin of cere (in front of nostril) 

 to tip of maxilla; culmen regularly decurved from base, more or less 

 distinctly ridged; gonys moderately convex, ascending terminally, 

 rather prominent basally, not distinctly if at all ridged; m.axlllary 

 tomium strongly incised immediately posterior to the subterminal 

 "tooth." Nostril moderate in size to rather small, nearly circular. 

 Wing long and pointed, the longest primary exceeding distal secondary 

 by half the length of wing; second or second and third primary (from 

 outside) longest, the first (outermost) much shorter than third; 

 inner webs of first pvud second primaries emarginated, the emargi- 

 nation on first opposite interval between tips of fifth and sixth, that on 

 second between tips of fourth and fifth; second and third primaries 

 with outer webs sinuated. TaU about two-thirds as long as wing, 

 distinctly rounded, the graduation sometimes (in F. tinnunculus) 

 equal to or exceeding length of middle toe wdth claw but usually 

 decidedly less, the retrices (12) relatively rather narrow, with rounded 

 tips. Tarsus much longer than middle toe with claw, one-fifth to a 

 little more than^one-sixth' (in F. [tinnunculus) as long as wing, its upper 

 portion feathered in front from about one-fom'th (F. tinnunculus) to 

 about one-third {F. sparverius) its length; acrotarsium covered (in 



