1S92.] Mearns 0)1 the American Sfarroxv Hawks. 255 



which is somewhat restricted; but in a very young example, collected by 

 Spencer F. Baird, at Carlisle, Pennsylvania, June 6, 1S44 (Smiths. Inst., 

 No. 1598), there is very little pale edging to the feathers of the upper sur- 

 face, which appear almost as sharply patterned as in adults, and the un- 

 derparts are strongly ochraceous fulvous. 



In the young there is also a stronger tendency to irregularity in the 

 pattern of the tail-feathers, in which the rufous is sometimes restricted to 

 the middle pair and irregular areas upon those next them, the outer four 

 or five feathers being variously banded, striped, or spotted with black, 

 cinereous, and ochraceous, especially on their terminal portion; but 

 variations in the amount of variegation of the tail are not confined to 

 young birds, adults, especially from the eastern United States, showing- 

 very considerable departures from the common style, in which the tail is" 

 plain rufous, subterminally banded with black, and tipped with (usualh) 

 white, with the outer feather, and often the outer portion of the one next 

 it varied with black and white, l)ut which quite frequently have strong 

 indications of additional black bands, and variable areas of ochraceous 

 white, ochraceous ash, and rusty, scattered promiscuously over the inter- 

 spaces. 



Tiie transverse barring of black on back and scapulars is sometimes 

 nearly as in adults, but the bars are usually more numerous, extending 

 nearer to the nape. The tips of the wing quills are broadly edged with 

 white; and the terminal band on the rectrices is more apt to appear rusty 

 instead of white, with the central pair often cinereous. 



I am unable to appreciate any intermediate phase of plumage between 

 that of the first plumage and the adult male of winter. The latter garb is 

 assumed gradually during September and October. 



Young females are still more similar to adults, the difference consisting 

 almost wholly in the deeper, more suffused markings, and sharper streak- 

 ing of the crown. 



Seasotial Variation. — An examination of 161 iriales develops the tact 

 that there is a well-marked difference between the plumages of winter and 

 summer, the difference being in the intensity ot coloring. The largest 

 series from one region comes from Arizona. The date of capture has 

 been accurately noted on the labels of 31 males from that Territory, of 

 which number 23 have acquired the adult plumage. Four are moulting 

 birds, changing from the plumage of summer to that of winter, taken from 

 September 15 to October 17; nine specimens, captured between the dates 

 of December 6 and February 19, represent the typical plumage of winter; 

 and ten, taken in April and May, are in the summer plumage of the resi- 

 dent Arizona bird, migrants having departed before that season. April 

 and May specimens are much paler throughout, this being especially 

 noticeable upon the. under surface, where the tawny ochraceous buff of 

 the winter plumage is replaced by cream-buff. The three black nape 

 patches appear more distinct, from the palingof the surrounding plumage 

 of the neck, which, in summer, shows as a collar of ochraceous buft". The 

 seasonal difference is so considerable that specimens could readily be as- 



