138 FALCONID^. 



upper tail-coverts inclining to ashy, broadly tipped with rufous, the 

 lower ones with white, with which also many of them are spotted ; 

 under surface of body dull rufous, inclining to white on the throat, 

 belly, and under tail-coverts ; the throat narrowly streaked with 

 black, the breast more broadly, and the flanks and thighs with large 

 bars or spade-shaped spots ; under tail-coverts white, with longitu- 

 dinal black streaks ; under wing-coverts I'ufous, with black streaks 

 widening out into bars on the lower series. 



Ols. The " brown-aud-white " dress, as the next plumage may 

 be called, is the one in which the young A. cooperi generally ap- 

 pears in museums. It is apparently gained without a moult from 

 the first stage by the rufous margins on the upper surface becoming 

 paler, and the white bases to the feathers becoming so extended that 

 the hind head and neck as weU as the side face become streaked 

 with white. The dark centres to the feathers of the nape have a 

 tendency to narrow ; so that this part also has a very streaked ap- 

 pearance. On the breast the streaks become narrower by degi-ees, 

 those on the sides of the body being still a little the broadest, the 

 bars on the flanks dissolving and leaving these parts more or less 

 distinctly streaked. Under tail-coverts pure white ; throat generaUy 

 streaked with black, but this character is so variable that sometimes 

 the throat is quite white, with only a few hair-like lines. These 

 are probably birds which have been hatched out earlier, and in 

 whom the characteristic development of a streaked plumage has 

 more chance of being perfected. The adult j)lumage must be gained 

 by a moult. 



Adult male. Above bluish slate-colour, the head darker and the 

 wing-eoverts also a shade deeper grey than the back, the shaft- 

 stripes distinct on upper sirrface ; lores and eyebrow whitish ; cheeks 

 ashy with a slight rufous tlage, and narrowly lined with black ; quills 

 brown, externally shaded with slaty, the secondaries grey like the 

 back, all barred with darker brown, more distinct below, where the 

 under surface is whitish ashy ; upper tail -coverts tipped with white ; 

 taU bluish slate-colour, with a broad white tip and crossed with 

 three bars of greyish black ; the lower surface greyish white ; throat 

 white, streaked with narrow blackish shaft-lines and tinged with 

 rufous on lower part ; rest of under siu'face clear rufous, spotted on 

 both webs or else barred with white, the upper breast more or less 

 uniform rufous ; under wing-coverts rufous white, the upper ones 

 streaked, the lower ones spotted with rufous ; under tail-coverts 

 white. Total length 15-5 inches, culmen 1-05, wing 9-3, tail 7*9, 

 tarsus 2-7, middle toe 1-5. 



Adult female. Similar to the male, but larger. Total length 17'5 

 inches, wing 10-3, tail 8-8, tarsus 3. 



Hah. Middle and southern States of North America, southwards 

 to Guatemala and Costa Rica. 



«. $ iuv. St. Quebec. D. W. MitcheU, Esq. [P.]. 



h. S luv. St. British Columbia. J. K. Lord, Esq. [P. J. 



r. 5 juv. St. West side of Rocky Mouu- J. K. Lord, Esq. [P.]. 

 tains. 



