Note 86 — Family FALCONIDÆ.—The Falcons. (continued 4)
Reading edition
Falco unicinctus, Temm. Pl. Col. 313, 1820. Morphnus unicinctus, Less. Man. Orn. I, 1828, 90. Astur unicinctus, Cuv. Règ. An. (ed. 2), I, 1829, 332.—Strickl. Orn. Syn. I, 221.—Kaup, Monog. Falc. 1850, p. 66. Buteo unicinctus, Gray, List B. Brit. Mus. 18.—Ib. Hand List, I, 7, No. 55. Nisus unicinctus, Less. Tr. Orn. p. 61. Hypomorphnus unicinctus, Tschudi, Fauna Per. pp. 17, 85. Spizageranus unicinctus, Kaup, Ueb. Senck. 1845, 260. Urubitinga unicincta, Lafr. Rev. Zoöl. 1849, 99.—Pelz. Orn. Bras. I, 1868, 3, No. 10.—Ib. IV, 1871, 394. Polyborus tæniurus, Tschudi, Av. Consp. Wiegm. Arch. 1844, 264.—Ib. Fauna Per. pl. ii, Juv. It seems that the South American birds of this species never attain the simple tricolored plumage assumed by the adult of the North American form, Temminck’s figure (Pl. Col. 313) representing the nearest approach to it that I have seen, in a large series of adult specimens. The following descriptions show the average adult of var. unicinctus:—
Adult male (No. 13,908, Chile; Lieutenant Gilliss). Resembling the immature of var. harrisi, as described on p. 1569 (No. 56,763). Primaries edged terminally with whitish; inner webs of tail-feathers mottled whitish for their basal half, not showing the regular transverse bars seen in the immature of var. harrisi; under surface of primaries almost wholly white, becoming ashy, barred with dusky, towards their ends. Wing, 12.00; tail, 8.30; tarsus, 2.90; middle toe, 1.60. Adult female (No. 13,907, Chile; Lieutenant Gilliss). Similar to No. 13,908, but the tibiæ more strongly barred. Wing, 12.50; tail, 8.30.
Specimens examined.—National Museum, 9; Philadelphia Academy, 9; Boston Society, 4; New York Museum, 1. Total, 23.
Measurements.—♂. Wing, 11.65–13.15; tail, 9.00–10.10; culmen, .82–1.00; tarsus, 2.78–3.40; middle toe, 1.52–1.75. Specimens, 8. ♀. Wing, 12.50–14.60; tail, 9.20–10.50; culmen, .90–1.02; tarsus, 3.10–3.40; middle toe, 1.60–1.85. Specimens, 6.