The Body of a Bird 293 
It is generally thought that the fact that, in captivity, 
Purple Finches and orioles frequently moult into yellow- 
ish hues, instead of their rightful tints, is due to some 
change in food. Indeed in many species the bright colours 
are wholly lacking after a year or two in captivity. But 
I have transferred a male Purple Finch, which had for 
several years moulted yellow, from a dark cage to one 
which was exposed to 
bright sunlight, and in 
one moult the bird as- 
sumed his original and 
normal colour. 
A more probable ex- 
ample of the effect of 
food upon colour is seen 
in our American Flamin- 
goes. In captivity these 
birds fade out moult by 
moult, until they become 
almost white, like the 
European species. By 
Fic. 233.—Effect of environment on Bob- 
mixing with their food white, shown by specimens from Min- 
nesota, Florida, and Cuba. (From a 
a quantity of some photograpb provided by the American 
Museum of Natural History.) 
strong but harmless dye, 
I have had them either retain their original colour for 
years, or at least the fading process has been appreciably 
lessened. 
The effect of climate upon colour is even more readily 
proved, and may be noticed in wild birds as well as in 
those in captivity. In regions which have a very dry 
