518 APPENDIX E 



common birds around our own homes, it is only necessary to 

 consider the bobolink and the scarlet tanager. The males of 

 these two birds in the breeding season put on liveries which are 

 not only not the " very best conceivable," but, on the contrary, are 

 the very worst conceivable devices for the concealment of the 

 wearers. If the breeding cock bobolink and breeding cock tanager 

 are not coloured in the most conspicuous manner to attract atten- 

 tion, if they are not so coloured as to make it impossible for 

 them to be more conspicuous, then it is absolutely hopeless for 

 man or Nature or any power above or under the earth to devise 

 any scheme of coloration whatsoever which shall not be concealing 

 or protective ; and in such cases Mr. Thayer's whole argument is 

 a mere play upon words. In sufficiently thick cover, whether of 

 trees or grass, any small animal of any colour or shape may, if 

 motionless, escape observation ; but the coloration patterns of the 

 breeding bobolink and breeding tanager males, so far from being 

 concealing or protective, are in the highest degree advertising ; 

 and the same is true of multitudes of birds, of the red-winged 

 blackbird, of the yellow-headed grackle, of the wood-duck, of the 

 spruce grouse, of birds which could be mentioned offhand by 

 the hundred, and probably, after a little study, by the thousand. 

 As regards many of these birds, the coloration can never be 

 protective or concealing ; as regards others, it may under certain 

 rare combinations of conditions, like those set forth in some 

 of Mr. Thayer"'s ingenious but misleading coloured pictures, ^ serve 

 for concealment or protection, but in an infinitely larger number 

 of cases it serves simply to advertise and attract attention to the 

 wearers. As regards these cases, and countless others, Mr. Thayer's 

 theories seem to me without substantial foundation in fact, and 

 other influences than those he mentions must be responsible for the 

 coloration. It may be that his theories really do not apply to a 

 very large number of animals which are coloured white, or are pale 

 in tint, beneath. For instance, in the cases of creatures like those 

 of snakes and mice — where the white or pale tint beneath can never 

 be seen by either their foes or their prey — this " counter-shading " 

 may be due to some cause wholly differing from anything concerned 

 with protection or concealment. 



There are other problems of coloration for which Mr. Thayer 

 professes to give an explanation where this explanation breaks 

 down for a different reason. The cougar's coloration, for instance, 

 is certainly in a high degree concealing and protective, or at any 

 rate it is such that it does not interfere with the animaPs pro- 

 tecting itself by concealment, for the cougar is one of the most 



^ Some of the pictures are excellent, and uudoubtedly put the facts truthfully 

 and clearly ; others portray as normal conditions which are wholly abnormal and 

 exceptional, and are therefore completely misleading. 



