BIRDS OF NORTH AND MIDDLE AMERICA 609 



and El Sombrero).— Dugand, Rev. Acad. Colomb., iii, 1940, 221 (Magda- 



lena-Caribbean area of Colombia).— Miller, Auk, Ixiv, 1947, 355 (Colombia, 



Upper Magdalena Valley; not common). 

 Polyborus vulgaris (not of Vieillot) Tschudi, Unters. Faun. Peru, Orn., 1846, 77 



(coast of Peru). 

 Polyborus caracara Schomburgk, Reis. Brit. Guiana, i, 1847, 386, 394 (near 



Pirara, Brit. Guiana). 

 Polyborus brasiliensis (not Falco brasiliensis Gmelin). — Gray, List Spec. Brit. 



Mus., pt. 1, ed. 2, 1848, 31, part (Brit. Guiana; Pund Island, w. Ecuador). — 



Pelzeln, Verb, zool.-bot. Ges. Wien, xii, 1862, 178, part (Rio Branco, 



Brazil). — Schlegel, Mus. Pays-Bas, ii. No. 9, livr. 2, 1863, 2, part (monogr.); 



No. 36, livr. 10, 1873, 137, part.— Taylor, Ibis, 1864, 79 (Orinoco, Venezuela; 



habits) . 

 Polyborus tharus (not Falco tharus Molina) Taylor, Ibis, 1860, 223 (common; 



Honduras) .—Sclater, Proc. Zool. Soc. London, 1860, 288 (Babahoyo, w. 



Ecuador).— Gray, Hand-list, i, 1869, 6, No. 35, part.— Sclater and Salvin, 



Proc. Zool. Soc. London, 1869, 252 (Maruria, Venezuela). — Allen, Bull. 



Essex Inst., viii, 1876, 82 (Rhome, lower Amazon). 

 Polyborus auduboni Orton, Amer. Nat., v, 1871, 624 (Quito Valley, Ecuador).— 



Berlepsch, Journ. fur Orn., 1884, 317 (Bucaramanga, Colombia; food); 



Ibis, 1884, 437 (Angostura, Venezuela). 

 Polyborus tharus b. var. auduboni Ridgway, Proc. Boston Soc. Nat. Hist., xvi, 



1873, 51, part (Brazil). 



Caracara plancus audubonii Hellmayr and Conover, Cat. Birds Amer., pt. 1, 

 No. 4, 1949, 286. 



POLYBORUS CHERIWAY PALLIDUS Nelson 



Tres MarIas Caracara 



Adult (sexes alike) . — Similar to that of Polyborus cheritvay audubonii 

 but paler, snuff brown to sepia instead of dark fuscous-black, and 

 smaller in size. 



Immature. — None seen. 



Juvenal (females only seen). — Similar to that of Polyborus cheriway 

 audubonii but much paler, the sepia to sayal brown of the latter 

 replaced by pale fulvous to tawny-olive; the chin and throat very 

 pale cartridge buff. 



Natal dovm. — Unknown. 



Adult male.—Wmg 355-366 (361); tail 185-194 (191.8); culmen 

 from cere 30.5-32 (31.3); tarsus 83-88 (85); middle toe without claw 

 47-50 (48.3 mm.) (4 specimens including the type). 



Adult jemale. —Wmg 373-375; tail 203-205; culmen from cere 32.5; 

 tarsus 86-88; middle toe without claw 51-53 mm. (2 specimens). 



Range. — Confined to the Tres Marias Islands, Mexico. 



Type locality. — Maria Madre Island. 

 Polyborus audubonii (not of Cassin) Grayson, Proc. Boston Soc. Nat. Hist., 



xiii, 1871, 9; xiv, 1872, 268 (Tres Marias Islands). 

 Polyborus tharus var. audubonii Lawrence, Mem. Boston Soc. Nat. Hist., ii, 



1874, 303, part (Tres Marias Islands). 



Polyborus cheriway pallidus Nelson, Proc. Biol. Soc. Washington, xii, 1898, 8 

 (original descr.; measurements; crit.); North Amer. Fauna, No. 14, 1899, 38 



