The occurrence of these three forms together is not remarkable, for two of them may reasonably be regarded as migrants from distant and probably widely separated regions. The third possibly represents a resident type, but on this point I have no direct evidence.
38. Falco columbarius suckleyi? Ridgw. Black Merlin.—A beautiful adult male Pigeon Hawk, taken at Fort Walla Walla Oct. 18, 1881, presents such a puzzling combination of characters that, after carefully comparing it with all the material available, I am still at a loss for a definite opinion regarding its precise identity or relationship. It most closely resembles highly colored, autumnal adults of F. columbarius, but the under parts, excepting the throat and a small central space on the abdomen, are rich rusty-ochraceous—almost orange-chestnut on the breast and tibiæ, while the usual cinereous above is intensified on the back to a nearly pure plumbeous; the markings of the under parts, also, are unusually coarse and numerous. In these respects it agrees with a bird in the National Museum from Santa Clara, California, but it differs from this specimen, as well as from every other adult that I have seen, in having the outer webs of all the primaries, excepting the first two, conspicuously marked with rounded spots of pale ochraceous.
With F. richardsoni it cannot be consistently associated, for the adult, as well as the young of that species, always has six distinct light bars on the tail, while the example under consideration possesses but five. Moreover, the adult male of richardsoni is very much lighter colored than the adult of columbarius, whereas the present bird is decidedly darker. The adult of suckleyi is unknown, but we should expect to find it, like the young, with sparse, inconspicuous spotting on the lining of the wings. In the Walla Walla bird these markings are as numerous and well-defined as in columbarius.
Taking all these considerations into account, and bearing in mind the unstable character of so many of the types furnished by this locality, it seems most reasonable to assume that Capt. Bendire’s specimen represents the adult plumage of a form which, although referable to suckleyi, is more or less intermediate between that race and true columbarius. But additional material must be forthcoming before the question can be definitely settled.
39. Falco richardsoni Ridgw. Richardson’s Merlin.—Of this well-marked species the collection contains two immature females, dated respectively Oct. 13 and Oct. 21, 1881. Neither of these calls for any special comment, but I take the present opportunity to characterize the adult plumage of the male, which apparently has not been previously described.[[112]]
Falco richardsoni, adult ♂ (author’s collection, Colorado Springs, Colorado, C. E. Aiken). Above pale ashy-blue, most of the feathers of the back, as well as the inner secondaries and many of the scapulars, with fine, black shaft-lines; crown tinged with ochraceous (probably wanting in the highest conditions of plumage), the black shaft-lines here very numerous, each feather being conspicuously marked; forehead and sides of head light ochraceous, the former with narrow black streaks, the latter with broader brownish ones; a well-defined nuchal collar of rusty-ochraceous with darker mottling; secondaries and primary coverts concolor with the back, but with light bars on their inner webs; primaries plumbeous-brown, margined with bluish-white and marked conspicuously on both webs with the same color, the markings on the inner webs being pure white and extending in transverse bars from the shaft to the edge of the feather, those of the outer webs ashy-white and in the form of conspicuous, rounded or quadrate spots; tail crossed by five dark and six light bars, the last of the latter terminal and pure white, the others more or less bordered by pale ashy-blue; all of the dark bars clear black excepting the basal two, which, on the central rectrices, are nearly uniform with the back, but decidedly darker than the light ones with which they alternate; throat pure white and immaculate; remainder of under parts pale ochraceous, deepest on the tibiæ and crissum, where it is decidedly tinged with rusty; feathers of the breast, abdomen, flanks and sides with median stripes of clear reddish-brown, these stripes broadest on the flanks (where they are sometimes actually transverse), narrowest across the anterior part of the breast, and everywhere with fine but inconspicuous dark shaft-lines; crissum entirely unmarked; under tail-coverts and tibiæ with conspicuous shaft-lines of dark brown; edges of wings pale ochraceous; under wing-coverts white, barred with reddish-brown; all the markings of the primaries showing distinctly on their under surfaces. Dimensions. Wing, 8.21; tail, 5.18; culmen (from cere), .50.
Were further proof wanting to establish this Falcon’s specific distinctness from F. columbarius, the difference in the adult plumage of the two would settle the question. The adult male of F. richardsoni has the mantle almost as light as that of a Herring Gull, while the conspicuous ashy-white spots on the outer webs of the primaries and the six light tail bands constitute equally well-marked characters. The specimen above described is essentially similar to five examples in the National Museum.
42. Astur atricapillus (Wils.) Bonap. American Goshawk.—The present collection includes four Goshawks, one an adult male, the remaining three young, or at least immature, birds in brown plumage. The adult is absolutely identical with Massachusetts specimens, and must be considered typical atricapillus. Two of the young agree well with Mr. Ridgway’s description of young striatulus,[[113]] but the third does not have the markings either darker or more extensive than do several of my New England examples, and the dorsal feathers have an even broader light (ochraceous) edging; the under parts, also, are strongly ochraceous, while the stripes on the flanks are neither cordate nor transverse. The latter characters, however, are probably worthless for they occur in a Tyngsboro (Mass.) bird.
Without going further into details I may sum up my conclusions as follows: (1) That two of Capt. Bendire’s specimens (the adult and the young bird just mentioned) are undistinguishable from typical atricapillus; (2) That the other two examples (both young or immature) differ from eastern birds in having broader, more linear black markings beneath and a narrower light edging on the feathers above, and are probably referable to a form more or less distinct from atricapillus; (3) That true atricapillus ranges westward at least to Fort Walla Walla, Washington Territory; (4) That striatulus, as at present defined, is a doubtfully tenable variety.
I am not at liberty to pursue the subject further, for I understand that Mr. Nelson is about to propose a new Pacific coast race which occurs, at least as a migrant, in the Western United States, and upon the young of which Mr. Ridgway apparently based his description of young striatulus.[[114]]