1926] Swarth: Birds cmd Mammals from the Atlin Region 105 



adults and young, and these differences are fairly well correlated with 

 certain regions. The specimen just described (as well as another 

 similar bird collected by Brooks) shows that differences of coarse or 

 fine markings cannot be explained as different stages reached by the 

 same individual. 



The last goshawk was seen by me near Atlin, September 19, but it 

 seems likely that the species remains to a later date. 



Buteo borealis harlani (Audubon). Harlan Hawk 



I collected in the Atlin region six specimens (nos. 44730-44735) 

 of a dark-colored Buteo that was of fairly common occurrence there. 

 The series consists of one adult female, three young males, and two 

 young females. Two of the young birds are just out of the nest, partly 

 feathered and not able to fly any distance, the other three are full 

 grown. In addition, Brooks collected an adult female and one young 

 bird. There are at hand also two specimens loaned by the Provincial 

 Museum, Victoria. Both are from the Atlin region, an adult female 

 (Prov. Mus. no. 2664) taken at Wilson Creek, June 19, 1914, an imma- 

 ture bird (Prov. Mus. no. 2666) from Blue Canon, August 18, 1914. 

 The first mentioned has been recorded as Buiea swamsard (Anderson, 

 1915, p. 12), the second as Buteo borealis alascensis (Anderson, loc. 

 cit., p. 11). 



The two adult females collected by Brooks and myself, both in 

 worn plumage and just beginning the annual molt, are essentially 

 alike. They are uniformly dark-colored, almost sooty, and in each 

 there are white markings at the base of the feathers that show through 

 more, probably, than they would in fresh plumage. New feathers 

 coming in are darker, more sooty, than the old, worn plumage. 



In Brooks' specimen the tail is mostly dark, with scarcely a trace 

 of red, it is mottled longitudinally with whitish, and there is a sub- 

 terminal band of blackish. There are two aberrant rectrices. One 

 has the inner web mostly white; the other is broadly barred with 

 dusky, there is a sharply defined triangular white spot at the tip of 

 the outer web, and the subterminal dusky band is broader than on the 

 other feathers. 



In the adult female taken by myself the exposed portions of the 

 rectrices are dusky, mottled longitudinally with whitish and with dark 

 markings, and there is a good deal of reddish on the terminal fourth 



