1263. Aesalon regulus.
Falco aesalon, Tunstall, Ornith. Brit. p. 1 (1771); Hume, Cat. no. 15 ; Biddulph, Ibis, 1881, p. 39; Scully, ibid. p. 417 ; C. Swinhoe, Ibis, 1882, p. 99; Barnes, Birds Bom. p. 17; St. John, Ibis, 1889, p. 151. Falco regulus, Pall. Reis. Buss. Reichs, ii, p. 707 (1773) ; Sharpe, Cat. B. M. i, p. 406. Aesalon regulus, Blyth, Ibis, 1863, p. 9; Gurney, Ibis, 1882, p. 160. Hypotriorchis aesalon, Gray, Gen. B. i, p. 20; Horsf. & M. Cat: i, p. 24 ; Jerdon, B. I. i, p. 35; Hume, S. F. i, p. 157. Lithofalco aesalon, Blyth, Ibis, 1866, p. 238; Hume, Rough Notes, p. 89; Jerdon, Ibis, 1871, p. 242.
Dourai , Bourela , H.; Retal turumti, Regi, Punjab.
Coloration. Adult male. Forehead, lores, and sides of the head whitish with dark shaft-streaks; supercilia rufescent, becoming rufous behind and running back to the rufous nuchal collar across the neck; crown of head and upper parts clear bluish grey, varying in depth of tint from quite pale to very dark, the feathers dark-shafted throughout, even on the rufous collar ; quills blackish, the inner webs barred with white except at the end of the primaries, and the outer webs tinged with bluish grey towards the base outside, inner secondaries coloured like the back ; tail bluish grey tinged white, with a broad black cross-band just before the white tip, and generally traces of other black bands ; throat white ; rest of lower parts and sides of the neck whitish, somewhat irregularly tinged with rufous, and with dark brown shaft-stripes that are narrowest in old birds.
Female. Very old females resemble the male, but these are of very rare occurrence : usually the female differs from the male in having the head dull rufous or brown, dark-shafted; the upper parts brown with more or less of a grey tinge and often with rufous edges to the feathers; the tail barred throughout, and the quills with rufous cross-bands; the nuchal collar and lower parts less rufous than in the male, and the breast and upper abdomen with much broader brown shaft-stripes, these frequently occupying more space than the white borders.
Young birds of both sexes resemble the female, but are browner with broader rufous edges to the feathers of the upper parts, with the crown rufous (dark-shafted), and with the tail alternately banded brown and white; the quills too are barred almost across.
Bill dark slaty grey, greenish at base of lower mandible; cere, legs, and feet yellow; irides brown (Hume).
Length of females about 12 ; tail 5.5; wing 8.75; tarsus 1.5 ; mid-toe 1.3; bill from gape .8: length of a male 11, wing 8.
Distribution. The Palaearctic region. The Merlin is found in the Western Himalayas, the Punjab and Sind, but only, so far as is known, in winter. It also visits Gilgit at the same season, and probably breeds farther north.
Habits, &c. For courage and speed no Falcon ranks before the Merlin, and, despite its small size, it was formerly a great favourite with Falconers, both in Europe and in Asia. It lives chiefly on small birds, and nests on the ground, laying 4 to 6 brick-red eggs of the usual falcon type.