Page:Condor4(5).djvu/15

 September, i9o2. [ THE CONDOR t I5 Status of the "Arizona Goldfinch" in California. BY JOSEPH GRINNELL. EVERAL persons have asked me why I left the "Arizona Goldfinch" out of the Check-list of California Birds. I had what appeared to me good reasons for not considering Astra- galinus psaltria arizon to be a bona fide subspecies at least as occurring in California, and I will here try to ex- plain my standpoint. The following are all the California records of this bird known to me. Chrysomitris W[ea:icanus CooPEa, Am. Nat. VIII, Jan. x874, x7 (one seen 5 miles north of San Diego). Chrysomitris psaltr2a, vat. arizoncv BREWER, & RIDGWA, Hist. N. Am. Bds. III, 1874, appendix, 509 (Encinetos Ranch, San Diego Co., San Buenaventura). Spinus psallria arizonce EMERSON, Zoe I, April, z89 o, 44 (Haywards); FzsI;x% N. Am. Fauna No. 7, May z893, 85 (Three Rivers); SLEVIN, Bull. Coop. Orn. Club I, July x899, 73 (Santa Clara); COI;N, Con- dor III, Nov. x9ox, z85 (Alameda); Condor IV, July z9o2, 94 (Los Angeles). I happen to have examined several of the above specimens as well as others not recorded; and I have seen a num- ber of living birds at close enough range to note their general peculiarities. In the ordinary plumage of the adult male psaltria, the back, scapulars and ear-coverts are uniform olive-green, with the feathers of the dorsum centrally more or less blackish. In well-marked specimens of so-called arizome, the whole upper parts together with the ear-coverts and sides of the neck are pervaded with shiny black like the top of the head, sometimes quite as deep and uniform. A bird of the latter type is thus easily distinguished frown its fellows of ordinary plumage in a flock at quite a distance, and there seems at first glance good grounds for consider- ing it a distinct and nameable form. But the contrary opinion rests on a number of indisputable facts which may be enumerated as follows: i. The differences are only evident in the case of the male. A female taken in company with a male of arizona shows no discernible differences from female psaltria of the same plumage age. 2. The characters of "arizome" are limited to the peculiar blackening or melanism of the upper parts. A care- ful comparison of psaltria examples with extreme specimens of "arizome" shows not a singledifference in measure- ments as a whole or proportionately, and there are no other color differences either in extent of white markings or tint of lower surface. 3. The melanism characteristic of "arizome" is altogether inconstant in quantity. I have seen no two exactly similar examples. Between the ex- treme of "arizonte" and normal fisaltria there is every intermediate condition. The melanism begins with the spread- ing and final coalescence of the dark centres of the dorsal feathers. Black feathers appear in the ear-coverts, which finally become umiform black to their lower limits; not that I believe that any such changes take place in the individual, but only to express the rel- ative conditions in a series of specimens. 4. Those birds called arizome appear throughout the range of psaltria (in California): they are not confined to any particular faunal area. They have not been recorded anywhere where psaltria has not, and psaltria has been found in no faunal area where speci- mens "inclining to arizome" have not. This is an .extremely important consid- eration; for observation has shown us that subspecies (which are incipient species) probably always originate through isolation (either by long dis- tance or intervention of barriers)in separate zoo-geographical areas. 5. There is no definite season of oc- currence of the arizome type which might go to show that it was a regular visitant from elsewhere. It occurs at all seasons and is found feeding and breeding in the same localities and at