19ii6] Swarth: Birds arid Mammals from the Atlin Region 107 



The immature birds are like the adults with the exception of the 

 tail. The tail feathers are dark sooty brown (the same color as the 

 body plumage) on the outer web, lighter colored on the inner web, and 

 crossed by eight or nine blackish bauds. The tail pattern, essentially 

 similar to that of immature calurus, differs from conditions in that 

 form in being darker (even than in the darkest calurus), and in that 

 the cross-bars are broader and fewer in number. Often, too, in young 

 harlard the cross-bars tend to be U-shaped or V-shaped on individual 

 feathers, rather than extending horizontally across. In two specimems 

 there is a faint tinge of rufous at the tip of the tail. These hawks are 

 generally dark colored birds but differ from even the darkest phase 

 assumed by calurus (of which there are both adult and young at 

 hand) in their sooty hue. In calurus there is a great deal of rich 

 brown or chestnut in the coloration, which is. altogether lacking in 

 the Atlin birds. 



In this series of specimens there is some variation, shown prin- 

 cipally in extent of the partly concealed white markings. In the 

 darkest colored birds the white markings in the body plumage are 

 mostly reduced to small paired spots on feathers that are blackish over 

 most of their area. The white markings are almost entirely concealed ; 

 the birds are almost uniformly dark. On the thighs and tibial plumes 

 there are the merest flecks of whitish. The lightest extreme is repre- 

 sented by a bird with broadly white-barred thighs and tibial plumes, 

 conspicuous bars and blotches on breast and belly, and with chin and 

 throat mostly white. 



The "soft parts" of two of the birds collected were colored as 

 follows. No. 44730; c? juv. (just out of the nest) : Eye stone gray; 

 feet pale greenish yellow; bill black; cere and gape greenish. 

 No. 44731; 5 ad: Eye dark sepia; feet greenish yellow; bill mostly 

 black, tinged with bluish along cutting edges. ; cere and gape greenish. 



One fact stands out clearly ; these birds are identical with the Falco 

 harlam of Audubon (1830, pi. 86), which is the Buteo torealis 

 harlard of the A. 0. U. Check-list (1910, p. 158). Our two adults 

 are closely similar to Audubon's plate, and they answer exactly the 

 description of Audubon's type specimen given by Sharpe (1874, 

 p. 191). The fact that the supposed young of harlani as described by 

 Sharpe (loc. dt) is not at all like the young birds I collected is of no 

 moment, for Sharpe 's bird (from "Western Mexico") was not harlami 

 at all. It appears to be the young of calurui. The same sort of mis- 

 take was made by Cassin (in Baird, 1858, p. 24) where one phase of 



