Page:Condor12(2).djvu/14

 64 TIlE CONDOR VoL. XII entirely black, that none are moslly black, or that there is less than half the area, or but little or no black on any of them. But if the middle wing coverts are "mostly black" and yet the wing is less lhan Lo what happens ? Would not such a bird, according to the definitions in the "key", be of another species ?' Paragraph ee applies to the different forms of phoeniceus, and says "middle wing coverts entirely buff, ochraceous or tawny, or if partly tipt with black the wing less than 130 (usually less than 127)." Does not the expression "if partly tipt with black" correspond rather closely with "middle wing coverts mostly black or else" of paragraph e ? So that it comes down to the proposition that when a specimen is found with the middle wing coverts partly tipt with black, if the wing is 'over 130 min. it belongs to the gubernalor group, and if under 130 in the p/oeniceus. But if this means that this figure is an average is it not rather a slight matter upon which to establish aspecific foundation ? And if this figure is a limit in itself is it not still allowing rather a slight margin ? And does it not show that there is every probability of intergradation somewhere? Farther on in the text, Under the actual descriptions of the forms, no mention is made of any black tipping whatever in poeniceus, nor to the above quotation from para- graph ee, with the exception of a foot note under the description of A. p. neulralis, p. 340, where Mr. Ridgway says "Specimens from southern California and northern Lower California seem to be somewhat different from the Great Basin examples, but I do not venture to separate them, the series of specimens being scarcely satis- factory. In adult males of this form many specimens show more or less black tip- ping to the middle wing coverts, this being observable in some specimens from the interior (Nevada)as well as some of those from the coast (San Diego County, etc.)" Then follows a table of meffsurements of such specimens, all of the wing averages being under 130. The extremes are not given, nor are the dates onwhich examples were taken, tho in wing measurements of this genus this is a very impor- tant matter, the amount of abrasion in a dry windy climate being so great that but little dependence can be placed upon the wing measurement of specimens taken in late spring or summer in any of our dry valleys where the trade wind blows strong- ly. My observations in the field lead me to believe that this abrasion is also affected by the food supply, in that where the birds gather their food upon the ground when walking thru dry stiff grass the amount of abrasion will be much greater than where the birds feed in swamps, alfalfa fields or green pasture lands. Now it happens that the measurements of the different forms of phoeniceus and gubernalor are the only differences given save the black' or no black on the middle wing coverts and more or less streaking of the females, mostly on the under parts. As for instance, the description given of A. gubernalorgubernalor, "Birds of North and Middle America", p. 326, is as follows: "Similar toA.phoeniceus phoeniceus, but adult with middle wing coverts black or with black tips: the adult female with under parts of body uniform black or sooty and upper parts nearly or quite uniform dusky: wing and tarsus longer, tail, bill, and middle toe shorter". But every measurement given overlaps those of A. p. phoeniceus in the extremes with the single exception of the wings of the females. The number of specimens from which the measurements were taken in this last case being so small, however, (7 in one case and 10 in the other) that there is but little doubt that these also would overlap if a larger number were measured. Now, if all these measure: merits overlap can they be used in differentiating a species? It would seem not, according to the prescribed rules. So that the difference between the two species, in the males, .comes down to the matter of black, or no black, on the middle wing coverts and streaking or no streaking on the females, and nolhing else!