Vol. XXIX1 



1912 



J Allen, The Concealing Coloration Question. 503 



Another element of confusion comes in when we consider recog- 

 nition-marks or identification-marks. Mr. John T. Nichols has 

 not avoided this confusion of ideas in his discussion of certain 

 recognition-marks in the January ' Auk '. The white stripe down 

 the wing of the Spotted Sandpiper in flight is an excellent field- 

 mark for identification purposes, but I very much doubt if the 

 bird is rendered one whit more conspicuous by it, as a mere bird. 

 Identification-marks have no necessary connection with conspicu- 

 ousness-: In fact, any distinctive marking on a bird may serve 

 as an identification-mark to the ornithologist, and it doubtless 

 may also serve as a recognition-mark for other individuals of the 

 species. The particular class of markings which have come to be 

 called recognition-marks are those which, in the case of birds, are 

 shown prominently in flight, generally on the wings, tail, or rump. 

 They doubtless serve as a means of identifying birds to others of 

 the same species when seen at some distance, the more striking 

 markings operating at the greater distances. But this, though 

 Thayer himself does not appear to have perceived it, does not 

 militate in the slightest against his idea that white markings on 

 wings, rumps, and tails are really concealing rather than revealing 

 in their effect. When I advanced this opinion in conversation 

 with a good friend of mine, he accused me of holding that a bird 

 could be at the same time revealingly colored to its friends and 

 concealingly colored to its enemies. This is not at all what I am 

 saying, however. My point is that these markings are not reveal- 

 ing to either friend or enemy; that is, they do not reveal the bird, 

 they simply identify the species. This, it will be seen, is of little 

 or no importance to the enemy, which is not concerned to know 

 whether the prey it is pursuing belongs to this or that species, but 

 it is of very vital importance to the species that individuals should 

 easily find one another and keep together. 



Here, then, are four special tendencies to error to be guarded 

 against in the stiuly of concealing coloration: the tendency to 

 regard any animal actually seen as conspicuous and to take no 

 account of those individuals which escape observation, the tend- 

 ency to see things as we know or suspect them to be rather than as 

 they really look to us, the tendency to confuse brightness of color 

 with conspicuousness, and the tendency to regard recognition- 



