1018 ' J Cam i; ito.v, Sivainxoit's Hawk in Montana. 393 



the male, and the second plumage corresponds to the description 

 of a young female, \o. M.oON in Xort.li American Birds, Vol. Ill, 

 p. 267, as before mentioned. Always darker than the adult male, 

 the two light normal female plumages coincide with his in the 

 pattern changes of the underparts, which, although differing in 

 color, show the same gradual diminution of the brown or chestnut 

 pectoral area and the whitening of the ventral surface. I agree 

 with Coues when he states that in the female " changes of plumage 

 with age affect chiefly the underparts; the back, wings, and tail 

 are more nearly alike at all times." 1 



Third Female Plumage. 



In this plumage the female Swainson's Hawk assumes the wdiite 

 throat, and, according to my observations, first begins to breed — 

 that is in her fourth year. She has now the appearance of a plain 

 brown and white bird. Her upper parts are precisely similar to 

 the third male plumage (light umber brown) except that the chest- 

 nut edging to the feathers of the mantle is absent in the female. 

 There are some bright chestnut lateral feathers concealed by the 

 wings, and a trace of this color on the thighs and abdomen. The 

 white ground of the latter is thickly variegated with wavy cross- 

 bars of the color of the back, and some lateral feathers near the 

 thighs are entirely brown. The large pectoral patch conforms in 

 extent to that of the third male plumage, but in color exactly 

 matches the back. The new primaries and tail feathers are slate 

 colored but fade to dark brown before the next moult while the 

 underside of the former is pale slate, blackening at the tips. 



Fourth Female Plumage. 



In this the upper parts are unchanged. The hawk whitens 

 considerably beneath, the pectoral patch is smaller, as in the 

 equal-aged male, and becomes mahogany color in place of brown. 

 The abdomen is thickly marked with triangular spots and cross- 



« Key to North American Birds, p. 547, Ed. 1887. 



