CHAPTER XIV 



SPECIAL FUNCTIONS OF MARKINGS. BIRDS, ETC. PROTECTIVE COLORATION 



OF NESTLINGS 



■ 



HEEDING henceforward the axiom established by the foregoing chap- 

 ters, viz.: All markings and patterns whatsoever are, under ordinary out- 

 door conditions, unfavorable to the conspicuousness of the thing that wears 

 them, we will examine further special phases of disguising-pattern in the 

 costumes of birds and other animals. 



A noteworthy type of generalized picture-pattern occurs, the world over, 

 on the wings and tails of hawks and owls. Most of them have, in some 

 plumage, conspicuously banded quills, whose pattern shows to best advantage 

 on the underside. On some kinds, like the Goshawks (Astur atricapillus 

 and A. palumbarius) in juvenile plumage, these bars on the quill feathers 

 form, when the tail and wings are broadly and fully expanded, a large series 

 of almost complete concentric circles. Potent must be the obliterative effect 

 of such a pattern, to the victim at whom the hawk is dashing, or above whom 

 he is momentarily poised, with widespread tail and wings. The reduplicate 

 circles of alternate light and dark, extending from the hawk's dim, streaked 

 body to the very tip of his great flight-feathers, and averaging more sharply 

 visible than the actual contours of the wings and tail, practically efface those 

 members, so that for an essential instant he is as it were dissolved and blended 

 outward, from a central core, into the banded and streaked promiscuous pat- 

 tern of the twigs and. branches behind and all about him. His menacing 

 body is the inconspicuous center of a maze of forest-colored circles, bewilder- 

 ing and confounding to the terror-stricken creature on whom he is about to 

 pounce. (See Figs. 64-66.) The light bands in these patterns of hawks' 



80 



