388 Mr. H. W. Hcnshaw on the various 



It is not, however, of the bird's general habits that I 

 would here speak, but of its plumages, which, it would seem, 

 have not been at all well understood. Of these there are two 

 "which are entirely distinct, viz. a light and a dark phase, each 

 having two stages, a juvenile and an adult. So different are 

 these phases that extreme examples might well be mistaken 

 for different species. In life the adult of the light phase 

 has the appearance of a white or albino Hawk ; while the 

 adult of the dark phase looks quite black or melanistic. 



This dichromatism may aptly be compared with that which 

 distinguishes the American Screech-Owl {Megascops asio), 

 with its red and grey phases, since it characterizes tiie bird 

 in all stages of growth, is dependent upon neither sex nor 

 season, and mating birds may or may not be alike in 

 colour. 



The two phases of this Hawk may be described as 

 follows ; — 



Light Phase. 



Adult stage. — Head and hind-neck white, or huffy white, 

 the feathers of the former with narrow blackish shaft- 

 streaks, those of the latter tijDped with large roundish spots 

 of the same. Sides of head and neck huffy, with more or 

 less brown ; back blackish brown ; rump lighter brown tinged 

 with ochraceous ; primaries blackish brown, the inner webs 

 above the notch white ; inner webs of secondaries black 

 barred, and tipped, as are the wing-coverts, with whitish and 

 ochraceous ; tail lighter brown, with faint marblings and 

 a wash of ochraceous ; rectrices with eight or nine narrow, 

 zigzag, more or less well-defined, blackish bars, which rarely 

 entirely cross the whitish inner webs ; under parts buff or 

 rusty buff, with a few feathers (sometimes but one or two) 

 on the flanks with brown shaft-streaks and small terminal 

 spots of same. Legs and feet greenish yellow; soles light 

 yellow ; bill blackish, but plumbeous at the base of the 

 lower mandible; iris light hazel. 



Juvenile stage. — Above and on the sides of the head 

 chocolate-brown, deepest on the hind-neck ; the feathers 

 lightly bordered with greyish and rusty ; rectrices ashy 

 brown, with irregular bars of blackish across each feather; 



