64 WITH THE U. S. NATURALISTS 



ground as would be seen through if transparent. 



Thus, a Woodcock bears vague markings, the 

 light and shade relations of which conform to dead 

 leaves, tw^igs and grasses irregularly disposed 

 over shadow-holes, Wilson's Snipe is indistin- 

 guishable among grasses and the Upland Plover is 

 hard to see among weeds. Brown Creepers are 

 the color of the trunks up which they creep, Snow 

 Buntings are the color of the snow. The young 

 Gulls, Terns, Skimmers, Stilts, and Avocets are 

 protectively colored, and if an intruder visits the 

 colony the strikingly marked adults fly away and 

 the youngsters squat motionless. 



This law of protective coloration may be 

 stretched too far. It explains many of the facts 

 of bird color, even some of the brightest, but it 

 does not explain all. In many cases, colors have 

 run riot in a bird's feathers and this impulse has 

 not been checked by the bird's natural enemies, 

 either, because the bird has learned better ways 

 of concealment, more wariness, or swifter flight. 

 Thus the Flamingo can afford to be a bright pink, 

 for there is no bird big enough to feed on him, the 

 Crow can dare to be black for he is one of the 

 wariest of all birds and the Humming Bird can 

 sport rich colors, partly because of his background 



