The Birds of El Paso County^ Colorado 553 



through winter and the following summer about three months 

 after leaving the nest. A large proportion of them and of 

 adults as well moult in August. The new feathers grow out 

 through the feathers of the old coat, gradually displacing them. 



I observed at this time that moulting young males were 

 acquiring as extensive a distribution of red as the brightest col- 

 ored adults, in fact after completion of the moult in both young 

 and' adult they are not distinguishable. Several specimens 

 illustrating this moult were preserved. Evidently then the ma- 

 jority of young acquire the perfect coat at the first autumnal 

 moult.* 



Later in 1907, on October 4, I obtained an undoubted 

 young male just completing its moult which is indistinguishable 

 externally from a female at the same season except perhaps 

 for a faint tinge of red on the jugulum. It suggests a parallel 

 case to that of Carpodacus cassini in which young males regu- 

 larly take the coat of the female at the autumnal moult. What 

 may take place in further development of the plumage in such 

 cases as that of this imperfectly marked House Finch is open 

 to further investigation. Po.ssible conclusions are that it might 

 develop some increase of red at the breeding season and ac- 

 quire a perfect coat at the second autumnal moult, or it might 

 develop at the second moulting a phase of scanty red diffusion 

 that would exist through life and prove an individual variation, 

 perhaps an individual characteristic transmittable to progeny. 



Orange-red mingled with or displacing crimson-red in 

 House Finches is accepted as indicating age. A male taken 

 May 22, 1904, shows a scanty reddish area of the orange shade, 

 so probably this bird lived a number of years without increas- 

 ing the amount of red. 



*The red of the autumnal coat remains pinkish through 

 early winter, gradually deepens toward spring, and acquires 

 its greatest intensity at time of breeding without a spring moult 

 or apparent abrasion. 



