_Onychotes_, RIDGWAY, P. A. N. S. Philad. Dec. 1870, 142. (Type, _O.
gruberi_, nov. sp.)
GEN. CHAR. Bill short, the tip remarkably short and obtuse, and only
gradually bent; cere on top about equal to the culmen, very broad
basally in its transverse diameter, and ascending, in its lateral
outline, on a line with the culmen; commissure only faintly lobed.
Nostril nearly circular, with a conspicuous (but not central or bony)
tubercle; cere densely bristled below the nostril, almost to its
anterior edge; orbital region finely bristled. Tarsus very long and
slender, nearly twice the length of the middle toe; toes moderate, the
outer one decidedly longer than the inner; claws very long, strong, and
sharp, and curved in about one quarter the circumference of a circle.
Tibial feathers short and close, the plumes scarcely reaching below the
joint. Feathers of the forehead, gular region, sides, and tibiæ, with
white filamentous attachments to the end of the shafts. Wing very short,
much rounded, and very concave beneath; fourth quill longest; first
shorter than ninth; four primaries emarginated, and one sinuated, on
inner webs; five sinuated on outer webs. Tail about two thirds as long
as wing, rounded. Outstretched feet reaching beyond end of tail.
This genus has no very near relatives among the American _Falconidæ_,
nor, indeed, among those of other portions of the world. It is, perhaps,
most closely related to the genus _Rupornis_, of South America, from
which, however, it is very distinct. It is represented by a single
species, the type of which, supposed to have come from California, still
remains unique.
The elongated legs, reaching considerably beyond the rather short tail,
the close thigh-plumes, the long and extremely acute claws (somewhat
like those of _Rostrhamus_), with the short, rounded, and very concave
wing, are its most striking peculiarities. Besides these distinguishing
features, the short, thick bill, very deep through the base, and the
filamentous attachments to the shafts of the feathers of certain parts
of the body, are also very characteristic. The latter feature may
possibly be a mark of immaturity, but I have seen nothing like it in
other _Raptores_, and it seems to be more analogous to the nuptial
ornaments seen in the Cormorants (_Phalocrocoracidæ_).
Species.
=O. gruberi.= Wing, 10.10; tail, 6.50; culmen, about .80; tarsus,
2.70; middle toe, 1.45; posterior claw, 1.00, its digit .80.
_Immature_ (?). Uniform grayish-umber, tinged with dull rufous on the
neck; lining of the wing and tibiæ dull grayish-cinnamon. Primaries
inclining to black, and showing just discernible, obscure hoary bars
on their basal half. Tail brownish-gray, with a hoary cast nearer the
shaft (not paler at the tip), and crossed with nine or ten narrow
bars of dusky, these becoming hardly distinguishable basally and
terminally. Inner webs of the primaries plain white anterior to their
emargination. Head laterally and beneath obsoletely streaked with
whitish. _Hab._ “California.”
Onychotes gruberi, RIDGWAY.