238 
NORTH AMERICAN BIRDS. 
extended, and colors generally darker. Young: Tail hoary grayish, 
growing gradually darker terminally, passing narrowly into dull whitish 
or rusty at tip, and crossed by numerous narrow and very indistinct bars 
of darker, these becoming gradually obsolete toward base of tail; gen- 
eral color of plumage brownish black, the lower parts more or less varied 
with whitish, buffy, or ochraceous. Downy young: Upper half of head 
dark sooty brown, becoming nearly black around eyes; hind-neck, upper 
back, and wings lighter sooty brown, fading gradually into dull brownish 
buff on posterior upper parts and buffy whitish on lower parts. Male: 
Wing 14.50-16.75, tail 7.50-9.00, tarsus 3.30-3.60, middle toe 1.55-1.80. 
Female: Wing 17.00-17.75, tail 8.25-10.30, culmen .95-1.05, tarsus 3.30- 
3.70, middle toe 1.60-1.80. Mest on low trees or bushes (usually a 
yucca). Eggs 2-4, 2.36 x 1.87, white, more or less blotched with reddish 
brown. Hab. Whole of Middle America, north to southern Texas. 
341. B. albicaudatus sennetti ALLEN. Sennett's White tailed Hawk. 
Genus URUBITINGA Lesson. (Page 223, pl. LXX., fig. 2.) 
Species. 
Common CHaracters.—Adults, uniform plumbeous-black, the upper tail-cov- 
erts, band across tip of tail, and other white bands on tail, pure white. Young: 
Above varied with blackish brown and ochraceous, the former prevailing; lower 
parts ochraceous or pale buffy, striped with dusky, the thighs barred with the 
same; tail crossed by numerous narrow bands of blackish and light grayish, mixed 
with white. 
a, Tarsus 4.30 or more; upper tail-coverts in adult plain white. 
b., Tail, of adult, with only two to three white bands, the broadest one more 
than 2.50 (2.60-4.50) wide; thighs often without white bars, these when 
present never (?) conspicuous; under wing-coverts destitute of white 
markings, or else merely speckled with white; wing 16.50-18.00, tail 
11.75-12.00, culmen 1.30, tarsus 4.90-5.00, middle toe 1.90-2.10. Hab. 
Tropical America, north to Costa Rica (and Nicaragua ?), south to Chili, 
Paraguay, and the Argentine Republic. 
U. urubitinga (GMEL.). Brazilian Urubitinga. 
b%. Tail, of adult, with three to four (usually three) white bands, the broadest 
one not more (usually much less) than 2.00 (1.20-2.00) wide; thighs 
always marked (usually conspicuously barred) with white; under wing- 
coverts always (?) barred or speckled with white; wing 15.15-16.50, tail 
10.50-11.50, culmen 1.10-1.35, tarsus 4.30-4.85, middle toe 1.60-1.90. 
Hab. Guatemala and southern Mexico, north to Vera Cruz, Tehuante- 
pec, and Mazatlan. U. ridgwayi GURNEY. Mexican Urubitinga.? 
1 Falco urubitinga Gut. 5. N. i. 1788, 265. Falco zonurus Suaw, Gen. Zool. vii. 1809, 62. Urubitinga 
zonura Scu., Trans. Zool. Soc. Lond. 1858, 262. 
2 Urubitinga zonura B. ——? Ripew., Bull. U.S. Geol. & Geog. Surv. Terr, ii. No. 2, 1876, 169. Urubitinga 
ridgwayi Gurvey, List Diurn. B. Prey, 1884, 77, 148, 
