LEAF AND TENDRIL 



marked in much the same way, as is also our 

 bobolink, which, in some localities, is called "the 

 skunk-bird," and neither of these birds has any 

 such reason to advertise itself as has the skunk. 

 Then here is the porcupine, with its panoply of 

 spears, as protectively colored as the coon or the 

 woodchuck, — why does not it have warning colors 

 also ? The enemy that attacks it fares much worse 

 than in the case of its black and white neighbor. 



The ptarmigan is often cited as a good illustra- 

 tion of the value of protective coloration, — white 

 in winter, particolored in spring, and brown in 

 summer, — always in color blending with its envi- 

 ronment. But the Arctic fox would not be baflBed 

 by its color; it goes by scent; and the great snowy 

 owl would probably see it in the open at any time 

 of year. On islands in Bering Sea we saw the Arctic 

 snowbird in midsummer, white as a snowflake, and 

 visible afar. Our northern grouse carry their gray 

 and brown tints through our winters, and do not 

 appear to suffer unduly from their telltale plumage. 

 If the cold were as severe as it is farther north, 

 doubtless they, too, would don white coats, for the 

 extreme cold seems to play an important part in 

 this matter, — this and the long Arctic nights. Sir 

 John Ross protected a Hudson's Bay lemming from 

 the low temperature by keeping it in his cabin, and 

 the animal retained its summer coat; but when he 

 exposed it to a temperature of thirty degrees below 

 64 



