PRAIRIE FALCON. Falco mexicanus Schlegel

Field characters.—Much larger than Sparrow Hawk, the body being somewhat larger than that of Band-tailed Pigeon; wings long and pointed; tail relatively small (pl. 44j). A narrow black streak down each side of face below eye and a brownish patch behind eye; upper surface pale brown obscurely barred; under surface white, spotted or narrowly streaked with dark brown on sides and belly.

Occurrence.—Visitant in fall at higher altitudes; possibly resident in small numbers in the arid territory east of Sierran crest. Observed by us only at Vogelsang Lake, August 31 to September 4, 1915, and above Ten Lakes, October 10, 1915. Ordinarily prefers the vicinity of cliffs adjacent to open country.

The Prairie Falcon is far larger than the Sparrow Hawk which, however, it closely resembles in form. It has, indeed, nearly the bulk of the Duck Hawk, but it is paler in color than either of these other falcons. In habits it closely resembles the Duck Hawk, with which, save for the difference in coloration, it might be confused.

We saw representatives of this species at only two places in the Yosemite region, as noted above; but individuals or pairs are likely to be met with anywhere in the more arid parts of the region, from the crest of the main Sierra Nevada eastward. The individual seen repeatedly near Vogelsang Lake, when on the wing showed plainly the glistening white forward under surface which is distinctive of this falcon alone occasionally it hovered with beating wings like a Sparrow Hawk. It does not seem likely that even a novice could confuse the pale-colored Prairie Falcon with any other raptorial species. (See pl. 44).