144 PROBLEMS OF BIRD LIFE 



green. IMrds of toiii])orate re.t^nons are rarely gay in color, 

 most of them being of soft browns or grays or blues or dull 

 olive shades. Many of the most northern land-birds and 

 mammals undergo a remarkable seasonal change, so that 

 they are brown in summer to match the heaths about them 

 and white in winter like the driven snow. Indeed, among the 

 few birds that you know yourself, do you not find sparrows 

 most commonly on the open fields and dusty roadsides, while 

 the greenish vireos and flycatchers, and the bright orioles and 

 tanagers, stay among the tree-tops and the blossoms ? It is a 

 hint of what Nature is doing on a large scale the world over. 

 Unless there is some good reason for another color, we shall 

 find the bird harmonizing with the prevailing surface color of 

 the region he inhabits, or with the light and shade of his 

 favorite haunts. 



But the very first birds that ever were, plain birds, such as 

 we imagined ourselves to be, must have been either of one 

 tint, or of we do not know what shades and mixtures. How 

 can we explain the change from this unknown primitive color 

 to the kaleidoscopic colors of birds to-day? Could we plain 

 birds change our colors as we changed our shapes ? 



Yes, we could change our colors, not as a man does his coat 

 (except in the seasonal moult, which is another problem), but 

 just as we changed our shape. Let us go back to our analogy 

 of boys and birds. If we were boys, could we not change our 

 color? Does your mother never say after a summer at the 

 seashore : " How your hair has faded ! How tanned and sun- 

 burned you are ! " And, after a long illness, your visitors 

 notice how pale you have grown. These are instances of boys 

 changing their color. Wind, sun, and rain — in other words, 

 climate — will alter a man's complexion very much. ^ In time 

 it will change a whole nation's so that a certain complexion 



