Scops asio bendirei,[[13]] var. nov.
California Screech Owl.
Ch. Sp. Similis S. asioni, sed auribus brevioribus; colore subtus magis cinerario, transversis lineis tenuioribus, pallidioribus, ac in medio haud interruptis. Nulla rubra conditione cognita.
Adult ♀ (No. 1,546, author’s collection, Nicasio, California, April 24, 1877, C. A. Allen). Above essentially similar to asio in its gray dress. Beneath ashy-white, every where thickly barred and streaked with black; the transverse bars being fine, numerous and regular, the shaft-stripes coarse and generally distributed from the throat to the crissum, both markings occurring as thickly on the median line of the breast and abdomen as along their sides. Wing, 6.20; tail, 3.30; tarsus, 1.50; culmen, .60; ear-tufts, 1.15.
Another adult from the same locality (♀, May 18, 1878, Coll. H. A. Purdie), measures: wing, 6.22; tail, 3.18; ear-tufts, 1.05: while seven unsexed specimens from Alameda county furnish the following extremes: wing, 6.01–6.52; tail, 3.22–3.72, ear-tufts, 1.05–1.25.
The above detailed characters, so far as my series goes, are sufficient to distinguish the California specimens from any gray examples of asio taken in the Eastern States. The chief difference is in the ground-color and markings of the plumage beneath. In asio the central line of the breast and abdomen is nearly always immaculate, while there is frequently a broad, entirely unspotted gular space: in bendirei these parts are as thickly barred and streaked as are the sides, while the ashy tinge of the entire lower surface and the much finer character of the transverse pencilling gives the plumage a clouded appearance which, although difficult of description, is very characteristic. The ear-tufts, also, are usually shorter than those of S. asio.
Among the nine examples before me there is remarkably little individual variation, much less in fact than with any equal number of asio which I have ever examined. The Alameda County specimens as a rule are rather more finely and faintly barred than the Nicasio ones and the ground-color beneath is of a slightly different shade, inclining more to clayey than ashy-white. In one bird the under surface is decidedly dull clay-color, which is so generally and evenly distributed that there is positively no approach to clear white even on the throat, lores, forehead or abdomen. But the essential characters already given are so well maintained on the whole that the description of the one chosen as the type will apply nearly as well to them all. This uniformity is doubtless largely owing to the absence in this race of any tendency to dichromatism, for much of the variation among the dichromatic ones can be traced to the combination in varying degrees of the colors of both phases, purely colored birds of either style being, at least in some sections, of comparatively rare occurrence. It is of course to be expected that larger suites of specimens will furnish occasional aberrant ones some of which may approach asio; but, so far as the present material is concerned, the tendency of variation is rather towards kennicotti and “tricopsis.” Indeed, as will be seen by comparing my diagnoses, the general coloring and markings of bendirei are so nearly like those of kennicotti in its extreme gray phase, that were it not for their wide difference in size it might be difficult to separate some of the specimens. That bendirei grades into the larger bird at the point where their respective habitats meet is shown by a specimen (No. 16,027, Nat. Mus.) from Fort Crook, Northern California, which is almost exactly intermediate in size, although more nearly like kennicotti in color and markings. As to our bird of the Southwest border, I believe that Mr. Ridgway is still undecided whether it really represents the tricopsis of Wagler or not, but he writes me that however this may turn out, he is now convinced that it intergrades with the form found over California at large and must hence be reduced to a variety of Scops asio. After a careful comparison of specimens I can unhesitatingly endorse this opinion, my Arizona examples of “tricopsis” differing from some of the more faintly barred bendirei only in the purer ash and sharper streaking of their dorsal plumage.
Save in cases where this fresh material has thrown new light on old data, I have deemed it unnecessary to go over any of the ground trodden by Mr. Ridgway in his elaborate and invaluable monograph of the genus Scops,[[14]] but the bearing of some of the present testimony has proved so far reaching that I venture, in concluding, to suggest the following rearrangement of the North American Screech Owls belonging to the S. asio group.
Dichromatic: erythrismal phase bright rufous.
Scops asio. Habitat, United States north of the Gulf States and east of the Rocky Mountains.
Scops asio floridanus. Habitat, Florida and Southern Georgia.