14 
THK CONDOR 
I Vol. Ill 
managed to get six of these. Two are 
in immature plumage, one shows an in- 
clination to orange, and three have yel- 
low in patches. 
Pains have been taken to make this 
list in some detail in order to show how 
frequent is the tendency to yellow; so 
frequent is it that we are hardly justi- 
fied in calling it an abnormal condition. 
The hypothesis that yellow is a more 
primitive color than red finds additional 
evidence in another genus, Cyanospiza. 
A spring male of C. ciris taken in 
Georgia has one yellow feather in its 
breast and five in its throat. Another 
male of this species shows yellow on 
the flank. ^ 
That these facts point to an ancestral 
bird of yellow plumage seems most 
reasonable to answer a question as to 
why so many birds are off color. 
Mr. Charles A. Keeler lias suggested 
that yellow is the more primitive color 
and red an intensification of the same 
pigment, although he gives no experi- 
mental data to support liis opinion. So 
high an authority as Dr. R. W. Shu- 
feldt wrote me, October lo, 1899, in re- 
gard to this subject: “I am inclined to 
agree with Mr. Keeler yellow birds 
preceded red ones in the histor}" of the 
group In time, and thus viewed, red may 
be but an intensification of the former 
color.” Mr. J. A-rmory Jefferies says; 
“Red feathers as those of the Flamingo, 
Cardinal Bird, and the like, are so col- 
ored by a red pigment-^similar to the 
yellow one.” 2 
Keeler^ lias called attention also to 
the fact that the House Finch when 
kept in captivity changes from red to 
yellow, and that^'hnany birds appear to 
become more brilliant in color as the 
breeding season approaches without 
either a moult or the wearing away of 
yie tips of the feathers.” This last 
point is indicated by the series of 
finches in my collection. He saysis 
“It is difficult to say whether the 
change in color of the caged house 
finch {Carpodacns niexicaniis frontalis) 
from red to yellow is due principally to 
a change in food, or to the confinement 
and general deterioration of the system 
from captivity. Food nevertheless, 
plays some part in this, as well as in 
many changes in the color of birds in 
the wild state, which, with the present 
lack of experimental data, are far too 
complex even to be surmised.”® 
I have quoted at length from Keeler 
in order to emphasize the richness of 
material ready to our hand. Here is an 
excellent chance for interesting and 
valuable experimentation. A study of 
the color change in our commonest bird 
would give big returns for the time in- 
vested. For such work, however, one 
should be permanently located where 
continuous out-of-door work might be 
done for a year or more. 
One more extract from Keeler’s work 
may not be out of place. “The mo.st 
significant interrelation of colors, how- 
ever, and one which I believe to be of 
wide application in the explanation of 
bird colors, is that between yellow and 
red. Whether these two colors are pro- 
duced by the same or a dift'erent pig- 
ment I am unable to say; but, however 
this may be, there is a high degree of 
probability that the red is simplj^ an in- 
tensification of the yellow. There is 
much to show that yellow is a n.ore 
primitive stage than red, and that the 
latter has always or nearly alwaj^s been 
developed from the former.”? 
It is to be hoped that someone who 
has time and facilities will feel enough 
interest in this matter to make at least 
a study of the moult and of the effect of 
food supply, varied as to quantity and 
and quality. 
^ ^ 
I. Note — Since writing the above I have examined a 
beantiful series of Hawaiian Island species, ]'’estiaria cocc- 
i)iea, in the collection of Mr. H. W. Henshaw of Hilo. In 
the adult plumage this bird is entirely red. The young, 
however, are yellow and Mr. Henshaw’s lot .shows the 
gradual change f rom yellow to red. 
2. Bull. Nnt. Ornith. Clnb. VII. P. 13I. 
3. Evolution of Colors of N. A. I.and Bds. P 156. 
4. 1. c. p. 136. 
,5. 1. c. p. 229. 
6. See on this subject, Birtwell, Aiit XVI. p. 313. 
7. 1. c. p. 154. 
