As typical of another subgenus (AEsalon) of Falcons we may select the Merlin (F. Regulus) of Europe and northern Asia, a bird one third less than the size of the Peregrine. The members of this group have the two outer quills with the inner webs emarginated near the tips, the tarsus not much longer than the middle toe, and the thighs longitudinally streaked, while the remainder of the plumage is mostly bluish gray above, the feathers with blackish central streaks, and whitish, huffy, or light rusty, striped with brownish, below.
The true Merlin is only about twelve or fourteen inches long, and may be known by the closed tail in the male showing but one black band, while the female shows about eight narrow pale bands. The upper parts are grayish blue, and the under parts reddish yellow, with longitudinal dark brown spots. It frequents the moors and mountains, feeding upon small birds, although it not infrequently kills Quail more than twice its own weight. The nest is a slight affair, usually placed on the ground among tall heather, and the eggs are four or five in number. Where it nests in trees, as it occasionally does, it makes use of the old nests of other birds, such as that of the Carrion Crow. It is capable of being trained for “hawking” and was formerly used to pursue Snipe, Larks, Black-birds, etc.