Above bluish ash, beneath reddish yellow, with longitudinal dark spots: no moustache: wings reaching to two-thirds the length of the tail.
F. AEsalon, Temm. Man. d'Orn. torn. i. p. 27. Merlin, Mont. Orn. Diet. Bew. Brit. Birds, vol. I. pp. 46 and 48. Selb. Must. vol. i. p. 51. pls. 18 and 18*.
Entire length eleven to twelve inches: breadth two feet.
(Adult male). Upper parts, including the tail, bluish ash, with the shafts of the feathers black: throat white: under parts reddish yellow, with dark brown, oblong-oval spots: quills with the inner webs barred with white: a broad black bar near the extremity of the tail; the tip itself white: bill bluish: irides brown: cere, orbits, and feet, yellow. (Female). Crown of the head dusky brown, streaked with black; nape white, with reddish brown spots: back and scapulars grayish brown, with reddish brown spots and black shafts: under parts yellowish white, with spots larger and more numerous than in the male bird: tail brown, with six or seven yellowish white bars. (Young). Upper plumage brown, the feathers edged with red: tail dusky, with several narrow bars of reddish brown; the tip of this last colour: quills brownish black, spotted or barred with reddish brown: under parts as in the female. (Egg). Mottled all over with two shades of dark red brown: long. diam. one inch seven lines; trans, diam. one inch three lines.
Supposed to be migratory in the South of England, which it visits during the winter months. Breeds in the counties of Northumberland, Cumberland, and Westmoreland, making its nest on the ground. Preys on small birds. Obs. This is a very variable species. The male in adult plumage is the Stone-Falcon of Latham, and other authors.