The subfamily Micrasturine comprises only the genus Micrastur with about eight species which range quite widely over Central America and northern South America. In addition to the characters already mentioned (p. 212), the Micrasturince have the tomia without tooth or notch, the sternum with a pair of large oval foramina in the posterior margin as in the Falconince, and four or more of the outer primaries with the inner webs sinuated near the middle portions. They are further described as stout and thick-set birds, with relatively long tails, short wings, and long legs, and a partial facial ruff, the latter suggesting the Harriers (Circus), though in general appearance they have more resemblance to certain of the smaller Goshawks, whence their popular name.
Of one of the Mexican species (M. Semitorquatus) Colonel Grayson writes entertainingly as follows: “Among the great variety of Hawks to be met with in a single day’s excursion in the vicinity of Mazatlan, none is so easily recognized as this peculiar and interesting species. I have only found it in the heavy forests or the immediate vicinity of a thickly wooded country, where its slender form and lengthened tail attract our attention as it swiftly glides through the tangled woods. It appears to be strictly arboreal in its habits, and possessed of wonderful activity, either in springing from branch to branch without opening its wings, or rapidly darting through the intricacies of the brush with apparently but little difficulty. I have seldom seen one of these Hawks in an open country, and have never seen one flying higher than the treetops where they are met with. Its wings are rather short, and its flight is performed by rapidly repeated strokes, only for a short distance at a time. It preys upon various species of wood birds, which it captures by darting upon them on the ground or in the bushes; but the Chachalaca (Ortalis) is its favorite game; this is a gallinaceous bird or wild chicken, about the size of, or lighter than, the common hen, and is entirely arboreal, seldom running upon the ground, but is able by its peculiarly formed feet to cling to, or spring rapidly through, the thickest branches with great agility; but this Hawk follows it with equal facility, until an opportunity offers to strike its prey, then both come to the ground together, the Hawk being the lighter bird. I witnessed a scene of this kind that took place when I was endeavoring to get a shot at a Chachalaca, as it was jumping about the very thick branches of an acacia, overgrown with lianes; it appeared to be in great distress, uttering its harsh notes of alarm, and spreading its fan-shaped tail; suddenly I saw one of these Hawks pounce upon it, when with harsh screams of terror the Chachalaca dragged his captor to the ground, where they struggled for a few moments, but the unfortunate bird was soon overcome. . . . They build their nest of dry twigs and moss, which is placed in a very tall tree, but below the higher branches; the only nest I have seen was inaccessible, therefore I am unable to describe the eggs.”