1911 J Allen, Roosevelt on Concealing Coloration. 477 



critical periods of their lives, tends to reveal them to their foes. In 

 others the coloration is of little consequence, one way or the other. 

 Birds and mammals living under precisely the same conditions 

 have totally different types of coloration, and display totally 

 different traits and habits when seeking to escape from enemies 

 or to capture prey. No universal laws can be laid down. Tenta- 

 tively, it is possible to give adherence to the conclusions which I 

 have sketched in loose outline above. We know that many birds 

 and mammals are concealingly colored. It is hard to say, at 

 least in some cases, whether this concealing coloration has been 

 produced by natural selection, or whether, however produced, it 

 has merely then been taken advantage of by the animals, which 

 have conformed their habits thereto, so as to get the utmost 

 benefit from it. In many birds and mammals sexual selection 

 or some similar principle has completely obscured in one sex the 

 workings of the law which tends to produce concealing coloration. 

 In many other birds and mammals both sexes are advertisingly 

 colored, and whatever be the cause that has produced this adver- 

 tising coloration it is evident that the circumstances of their lives 

 are such, that their habits and traits of mind are such, as to render 

 the question of concealing coloration a negligible element in their 

 development. 



" The species of birds and mammals with a complete obliterative, 

 or concealing, or protective, coloration, are few in number compared 

 to those which possess (either all the time, or part of the time, 

 or in one sex for all the time or part of the time) a conspicuous or 

 revealing or advertising coloration, and to those in which the 

 coloration is neither especially advertising nor especially concealing. 

 As regards the great majority of the species, the coloration, whether 

 concealing or not, is of slight importance from the standpoint of 

 jeoparding or preserving the bird's or mammal's life, compared 

 to its cunning, wariness, ferocity, speed, ability to take advantage 

 of cover and other traits and habits, and compared to the character 

 of its surroundings." 



In an Appendix of ten pages Mr. Roosevelt takes occasion to 

 reply to Mr. Thayer's criticisms of Roosevelt's 'African Game 

 Trails,' in one of the appendixes to which the author takes ex- 

 ceptions to Mr. Thayer's statements in his ' Concealing-Coloration 



