BIRDS OF NORTH AND MIDDLE AMERICA 589 



Plumage and coloration. — Head normally feathered, but feathers of 

 gular region rather loose webbed.^ 



Tail transversely mottled and more or less distinctly barred with 

 dusky on a white ground, the tip dusky in a broad, well defined band; 

 tail coverts white; base of primaries mottled with whitish. 



Nidification.—'Nest in trees, bushes, rushes, or on the ground among 

 grasses, or other herbage. Eggs (3-4) round ovate, more or less 

 heavily blotched and spotted with reddish brown, sometimes almost 

 uniformly of this color. 



Range. — Greater part of South America, one species extending to 

 western Panama. (Two species.) 



KEY TO THE SPECIES AND SUBSPECIES OF MILVAGO 



a. Upper tail coverts pure white or pale buffy white, unmarked. 

 b. Upper surface brownish with a distinct ashy tinge. 



c. With no white tips to the feathers of the upperparts. 



M. chiraango chimango, ad. (extraUmital)^ 



8 According to Nitzsch, the pterylosis of Milvago is similar to that of Daptrius, 

 "but stronger in all its parts, and the spinal tract different, having a remarkably 

 short fork, with its limbs broad and strongly divergent. The posterior portion 

 reaches this fork with its most anterior sparse feathers." 



9 Polyborus chimango Vieillot, Nouv. Diet. Hist. Nat., v, 1816, 260 Paraguay 

 and Rio de la Plata); Schlegel, Mus. Pays-Bas, ii, No. 9, livr. 2, 1863, 6, part 

 (monogr.). — Polyborus chimango d'Orbigny and Lafresnaye, Synop. Avium, 

 1839, 3, part (Argentina; Patagonia; BoUvia). — Haliaetus chimango Lesson, 

 Trait6 d'Orn., 1831, A^.—Caracara chimango D'Orbigny, Voy. Amer. M^rid., Ois., 

 1835, 60, part. — Milvago chimango Gould, Zool. Voy. Beagle, pt. 3, 1841, 13, 14, 

 part; Gray, List Spec. Brit. Mus., pt. 1, ed. 2, 1848, 29, part; Gurney, Descr. Cat. 

 Rapt. Birds Norfolk and Norwich Mus., pt. 1, 1864, 26, part (Buenos Aires, 

 Argentina; habits) ; Cat. Birds Prey, 1894, 18, part; Sclater and Salvin, Proc. Zool. 

 Soc. London, 1869, 252 (Lake Valencia, Venezuela); Durnford, Ibis, 1876, 161 

 (Buenos Aires); Ridgway, U. S. Geol. and Geogr. Surv. Terr., ser. 2, Bull. 6, 

 1876, 467, part (monogr.); Withington, Ibis, 1888, 470 (Lomas de Zamora, 

 Argentina); Crawshay, Birds Tierra del Fuego, 1907, 7 (habits); Hartert and 

 Venturi, Nov. Zool., xvi, 1909, 238 (Barracas al Sud and Tucumdn, Argentina; 

 descr. eggs); Stone, Rep. Princeton Univ. Exped. Patagonia, ii, pt. 4, 1915, 582 

 (synonymy; descr. plumages; habits); Swann, Synopt. List Accip., pt. 1, 1919, 9; 

 Chubb, Ibis, 1919, 279 (Mendoza, Argentina, 850 m.); Hellmayr, Nov. Zool., 

 xxviii, 1921, 175 (crit.) : Daguerre, El Hornero, ii, 1922, 265 (Rosas, Argentina); 

 Seri6 and Smyth, El Hornero, iii, 1923, 43 (Santa Elena, Argentina); Wilson, 

 El Hornero, iii, 1923, 85, figs. 1, 2 (nesting habits). — Milvago chimango Bonaparte, 

 Consp. Gen. Av., i, 1850, 13; Rev. Mag. Zool., vi, 1854, 539; Gray, Hand-list, i, 

 1869, 5, No. 30, part (Brazil); Sclater and Salvin, Nom. Av. Neotr., 1873, 122, 

 part (Argentina; Patagonia); Gurney, List Diurn. Birds Prey, 1884, 13, part; 

 Ihering and Ihering, A v. Brazil, 1907, 84 (Rio Grande do Sul) ; Brabourne and 

 Chubb, Birds South Amer., i, 1912, 63, part (se. Brazil; Uruguay; Paraguay; 

 Argentina; Tierra del Fuego). — Milvago chimango chimango Swann, Synop. Accip., 

 pt. 1, 1921, 16 (se. Brazil to Tierra del Fuego; Monogr. Birds Prey, i, 1925, 91 

 (monogr.).— Peters, Check-list Birds of World, i, 1931, 279.— ZWder (Milvago) 

 chimango Kaup, Mus. Senckenb., iii. Heft, 3, 1945, 262. — Ibicter chimango Kaup, 



