144 JUNCO CINEEEUS VAR. CANICEPS. 



under-parts shaded with pinkish-brown on the sides. Yonug birds of this form come 

 very near immature hyemalis ; Mr. Ridgway has noted intermediate specimens (Pr. 

 Phil. Acad. 1869, 126), and complete inosculation of the two is claimed by Mr. Allen. 

 In both of these the white of the under-parts is abruptly defined against the dark 

 colors. In " caniceps" the main color is pale grayish-plumbeous, fading insensibly 

 into the white below ; the lores are definitely blackish, and the interscapular region 

 alone is ferruginous — this color forming a small triangular area ; the bill is pinkish- 

 white, aSi in the foregoing. This form passes through "dorsalis" into the extreme of 

 typical cinereus,"n\ which the characters are as given in a preceding foot-note ; while 

 on the other hand specimens have been found showing pinkish-brown sides, and other- 

 wise tending to the characters of oregonits— these constitute J^ " aiwiectens " of Baird. 

 The probability that some of these intermediate specimens are really hybrids is very 

 strong, but has not been proven by detection of opposite sexes of the two actually 

 breeding together ; so it remains an open question. Mr. Allen inclines to dispose of 

 the matter of hybridism upon the hypothesis that the doubtful specimens are simply 

 examples of intergradation of character, according to climatic or other influences 

 resulting from geographical distribution. However this may be, it is certain that all 

 three forms, in their typical development, occur together. This is the case in Arizona, 

 for instance, where I found them all. To show how intimately they are associated, I 

 may state that once, on firing into a flock of Snow-birds, I picked up, after the single 

 discharge, several oregonus, one pure eaniceps, and a single typical hyemalis. 



The Gray-headed Snow-bird is not nearly so common in Arizona, in 

 winter, as the Oregon species ; still, I frequently observed it in com- 

 pany with the latter, and obtained several specimens. It arrived at the 

 same time as oregonus, and departed with it, probably to breed in the 

 neighboring higher mountains. It undoubtedly breeds at Laramie, since 

 Dr. Hayden's specimens were taken in August. It appears to be com- 

 mon in' Colorado, from the eastern bases of the foot-hills up the moun- 

 tains to above timber-line. 



In the American Naturalist, as above cited, Mr. Ridgway takes the view that all the 

 forms of Junco are geographical races of one species. He discusses the matter very 

 ably and upon good grounds. Referring the reader especially to this article, I sub- 

 mit;, in further elucidation of the difficult problem, the following notes received from 

 Mr. T. Martin Trippe, premising, however, that in so doing I am not necessarily com- 

 mitted to his conclusions. (The biographical notes refer to Idaho Springs, Colorado.) 



Junco hyemalis var. hyemalis. — ^Eastern Snow-bird. This Snow-bird is never abun- 

 dant, nor does it breed in Clear Creek County; the only period during which it is at 

 all common being March and the early part of April. During fall and winter, it is a 

 rare visitor ; but among the foot-hills, and edge of the plains, it is abundant, as Mr. 

 Aiken, of Fountain, informs me, during November and March, bnt is rarely met with 

 in midwinter. I have never seen it higher than 8,000 feet, and it is far more common 

 below 7,000. It is similar in its habits and notes to the eastern bird, and is almost 

 always found in flocks with the succeeding variety. 



J. hyemalis var. oregonus. — Oregon Snow-bird. Where this species begins and hyema- 

 lis ends, it would puzzle even Brehm to decide ; for while it is easy to select two speci- 

 mens representing the species as described in the books, a large series collected at the 

 same time and from the same place, will show all possible gradations between the two, 

 many individuals combining the characteristics of both. Thus, the rusty-rnfous back 

 of oregonus i« sometimes found without the purplish sides, which are supposed to belong 

 to the latter bird ; or, vice versa, specimens of hyemalis with scarcely a wash of rusty on 

 the back, are occasionally marked by decidedly purplish sides. Of -all the varieties 

 these two are the most unstable and seem to blend most perfectly with each other. 

 They associate together, and have the same habits and notes ; they appear and disap- 

 pear about the same time ; but of the two, oregonus is most abundant, being twice or 

 thrice as numerous as hyemalis. Mr. Aiken informs me that the present-variety arrives 

 in his vicinity — which is a short distance south of this region, on the edge of the 

 plains — about the middle of October, and remains till April, thus showing a slightly 

 more southern habitat than that of the preceding race. 



J. caniceps. — Chestnut-backed Snow-bird. Abundant, and the only species that 

 breeds here. The Chestnut-backed Snow-bird arrives about the middle or latter part 

 of March, two or three weeks previous to the departure of the two preceding races, 

 with whom it associates as long as they remain. As the snow disappears, it gradually 

 works its way upward, and by the middle of June has disappeared from the regions 

 below 8,000 feet. It breeds most abundantly in the upper woods, from the extreme 

 limit of the willows down to 1,000 or 1,200 feet below timber-line ; and more sparingly 

 below that point as far down as 8,-500 feet, and occasionally as low as 7,500 and even 

 7,000 feet. In October it descends to the lower valleys, and soon disappears altogether. 

 On the plains it is common in P^oember ajid March, but rare during midwinter. In 



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