264 BULLETIN 5 0, UNITED STATES NATIONAL MUSEUM 



BUTEO JAMAICENSIS FUMOSUS Nelson 



Tres MARfAS Red-tailed Hawk 



Adult (sexes alilve). — Similar to that of B.j. socorroensis, but with 

 head and neck plain sooty brown, the throat more or less streaked with 

 white; chest and breast not white medially, but cinnamon-brownish, 

 marked with black shaft streaks, and with lighter spots on median 

 portion; thighs heavily barred with brown; sides and flanks more 

 rufous; upperparts much more uniform dusky, the longer scapulars 

 without distinct, if any, pale spotting. 



Juvenal. — Similar to that of B. j. borealis, but slightly paler, more 

 grayish earth brown above and much more heavily streaked on the 

 breast and abdomen; the thighs heavily barred with dark brown and 

 washed with pinkish cinnamon. 



Natal down. — Not known. 



Adult male.— Wing 368-370; tail 228-230; culmen from cere 27-28; 

 tarsus 86-87; middle toe without claw 43-44 mm. (2 specimens). 



Adult female. — Wing 395; tail 235.5; culmen from cere 30; tarsus 87; 

 middle toe without claw 46.5 mm. (1 specimen). 



Range. — Resident in the Tres Marias Islands, Mexico. 



TTjpe locality. — Maria Madre Island. 



Buteo borealis var. montanus (not Buieo montanus Nuttall) Lawrence, Proc. 



Boston Soc. Nat. Hist., ii, 1874, 301, part (Tres Marfas Islands). 

 Buteo borealis var. calurus (not Buteo calurus Cassin) Lawrence, Mem. Boston 



Soc. Nat. Hist., ii, 1874, 301, part (Tres Marfas Islands). 

 Buteo borealis, var. costaricensis Ridgway, in Baird, Brewer, and Ridgway, Hist. 



North Amer. Birds, iii, 1874, 285, footnote, part (descr. supposed young 



from Tres Marias Islands). 

 Buteo borealis fumosus Nelson, Proc. Biol. Soc. Washington, xii, 1898, 7 (Maria 



Madre Island, Tres Marias group, nw. Mexico; coll. U. S. Nat. Mus.); 



North Amer. Fauna, No. 14, 1899, 37 (Tres Marias Islands; descr. young). — 



SwANN, Synopt. List Accip., pt. 2, 1919, 48; Synopsis Accip., ed. 2, 1922, 80; 



Monogr. Birds Prey, i, 1926, 397 (monogr.). — McLellan, Proc. California 



Acad. Sci., ser. 4, xv, 1926, 297 (Maria Madre, Mexico). 

 Buteo fumosus Sharpe, Hand-list, i, 1899, 256. — Salvin and Godman, Biol. 



Centr.-Amer., Aves, iii, 1900, 65. 

 Buteo jamaicensis fumosus Peters, Check-list Birds of World, i, 1931, 232 



(distr.). — HoussE, El Hornero, viii, 1941, 47, in text (breeding range, on 



map). 



BUTEO JAMAICENSIS SOCORROENSIS Ridgway 



Socorro Red-tailed Hawk 



Adult (sexes alike). — Similar to the pale phase of B. j. calurus, but 

 with larger and stouter feet; the underparts more uniformly pale 

 cinnamon-rufous or vinaccous-cinnamon, with the dusky markings on 

 the sides and abdomen smaller and fewer; the thighs deep vinaceous- 

 cinnamon indistinctly barred with paler, vinaceous-buff; scapulars 

 blotched with vinaceous-cinnamon. 



