610 BULLETIN 5 0, UNITED STATES NATIONAL MUSEUM 



(Tres Marfas; habits, etc.). — Bailet, Auk, xxiii, 1906, 387 (White Rock 

 and Cleofa Islands, Tres Marfas). — Swann, Synopt. List Accip., pt. 3, 

 1920, 8; Synop. Accip., pt. 1, 1921, 12; Monogr. Birds of Prey, i, 1925, 72 

 (monogr.). — McLellan, Proc. California Acad. Sci., ser. 4, xv, 1926, 298 

 (Maria Madre); xvi, 1927, 19 (Marfa Madre; plum.). — Peters, Check-list 

 Birds of World, i, 1931, 281. 



Polyborus pallidus Sharpe, Hand-list, i, 1899, 243. — Salvin and Godman, Biol. 

 Centr.-Amer., Aves, iii, 1901, 127. 



Caracara plancus ■pallidus Hellmayr and Conover, Cat. Birds Araer., pt. 1, 

 No. 4, 1949, 287 (syn.; range). 



POLYBORUS LUTOSUS Ridgwsy 



Guadalupe Caracara 



Adult (sexes alike). — Forehead, crown, occiput, lesser upper wing 

 coverts, secondaries, primary coverts, alula, terminal portion of 

 primaries, entire lining of the wing (including axillars), and terminal 

 band on the tail (25-40 mm. wide) blackish brown, sometimes almost 

 black; auriculars, cheeks, and throat dirty whitish or light Isabella 

 color; rest of the plumage marked with transverse bars of brownish 

 black or dark brown and brownish white or light Isabella color; the 

 bars most regular on the lower surface (and often the upper tail 

 coverts), where they extend uninterruptedly from the foreneck to 

 the crissum, the bars of the two colors being about equal in width, 

 the dark ones fainter on the crissum, narrower and more distinct on 

 the foreneck ; on the middle and greater wing coverts they are similar 

 to those on the abdomen; on the interscapulars the dark ones are 

 much wider than the light ones, and nearly black; on the scapulars 

 dark bro\\Ti prevails, the lighter bars being almost obliterated; the 

 basal half or more of the outer five or six primaries are Isabella white, 

 transversely mottled, or raggedly barred with grayish and dusky, 

 the shafts clear yellowish white; tail, except dusky terminal band, 

 marked with ragged transverse bars of brownish gray and Isabella 

 white, of equal widths; the bars of the two colors separated by a 

 narrower zigzag bar of dusky; orbital and loreal skin and cere chrome 

 yellow (changing to salmon after death); iris light bro\vn; bill pale 

 bluish white; tarsi and toes chrome yellow; claws blackish, 



Juvenal (sexes alike). — Remiges and rectrices the same as in the 

 adult, but the terminal band of the tail narrower and less sharply 

 defined ; pileum and lesser wing coverts dark brown, the feathers with 

 lighter brown edges (these sometimes worn oft"); back and scapulars 

 dull grayish brown, the latter plain, the former usually slightly 

 variegated v/ith lighter borders and tips to the feathers; lower parts 

 light grayish brown, with longitudinal dashes of dirty whitish; upper 

 tail coverts dull grayish brown, tipped with dirty whitish and some- 



