176 BULLETIN 16 7, UNITED STATES NATIONAL MUSEUM 



ground. It was a huge mass of sticks, a platform that had been flattened to 

 such an extent that the young birds were in plain sight from the ground 

 ueax-by. On July 6 it held two young, with feather rows showing through the 

 down on the breast. Returning on July 20 we found the young birds gone, 

 but discovered them in nearby trees. They had evidently just left the nest ; 

 wing and tail feathers were not yet full grown, and they could make but 

 short flights. On August 11 a second brood, again of two birds, was found, 

 obviously just out of the nest. These birds could fly but feebly ; when found 

 they were on the ground in dense spruce woods. One young bird and one 

 parent were shot. 



Plumages. — The downy young and early nesting plumages of Har- 

 lan's hawk seem to be unknown. Mr. Taverner (1927) has illustrated 

 two nearly fully fledged nestlings, nearly fully grown, taken with 

 their two parents in the Mount Logan area, Chitina River Glacier, 

 Alaska, on July 19, 1925. These two specimens are quite unlike (see 

 his pi. 3, figs, 4 and 5), one being the darkest and the other the 

 lightest colored of the brood of three. The male parent is a dark 

 bird, which Mr. Taverner calls "an almost typical black-phased 

 calurus*'^ but which Dr. Bishop calls the second-year plumage of 

 harlani in the dark phase (see his pi. 3, fig. 2). The female parent 

 (his pi. 3, fig. 3) we can all agree to call a typical adult hcvrlmii in 

 the light phase. The reader may form his own conclusion, but it 

 seems to me that Dr. Bishop is probably more nearly correct. 



There seems to be no doubt that harlani has two very distinct color 

 phases, an extremely dark phase and an extremely light phase. 

 These two phases evidently interbreed, causing considerable con- 

 fusion. The spotted tail is characteristic in the adults of both 

 phases, but the immature birds are not so easily recognized. Norman 

 A. Wood (1932), who has made a careful study of a large series of 

 Harlan's hawks, tells me that in the dark phase of the first-year 

 plumage harlani can be distinguished from the similar stage of the 

 dark phase of calmnts by numerous and conspicuous white spots, 

 some of them rather large, on the webs of the feathers of the back, 

 scapulars, and wing coverts, and by the generally blacker tone in the 

 entire plumage. In calurus, the general tone is browner and the 

 dark-brown feathers are white only basally. 



The immature plumages of the light phase are much like similar 

 stages of krideri and are nearly as light colored. Specimens of 

 immature birds in this plumage have been collected in Alaska and 

 British Columbia, which have suggested the extension of the range 

 of krideri into that region, which seems to be too far removed from 

 its normal range. I believe that the two young birds collected by Mr. 

 Dixon, at Flood Glacier on the Stikine River, on July 31, 1919, and so 

 well described by Mr. Swarth (1922), were harlani in this plumage; 

 it is interestingr to note that Mr. Swarth was "disinclined to regrard" 



