CHAPTER IV 



BACKGROUND-PICTURING ON OBLITERATIVELY- SHADED BIRDS. FIRST TYPE, 

 PICTURING OF THE LARGER DETAILS OF THE NEARER GROUND, ON 

 TERRESTRIAL BIRDS 



HEREWITH we leave the arid field of demonstration with artificial 

 models, and launch into the wonderland of actual Nature. If we 

 compare the numerous cases of evident background-picturing on the bodies 

 of obliteratively-shaded birds, we find that they are clearly separable into 

 several main classes or divisions. Many of the species, for instance, have a 

 wonderfully minute and intricate pattern, while others, almost equally famous 

 for their 'invisibility,' are marked in a much simpler and more blotchy 

 way. The finely-patterned class is again divisible into two very different 

 branches, as we shall see later on. This chapter, as the heading indicates, 

 is to be devoted to the more blotchily-marked type of pattern-bearing ' In- 

 visibles.' The best examples of this type are terrestrial birds which live 

 among fallen leaves and sticks, etc., or among weeds and grasses, patches of 

 mud, and pools of water. Preeminent among them are the Snipes and 

 Woodcocks (Philohela, Gallinago, etc.), — Figs. 20-26. 



The American Woodcock (Philohela minor) is a beautiful representative 

 of the class. See Figs. 20-22, reproduced from photographs of live Wood- 

 cocks in Nature, and Figs. 23-24, which show photographs of a dead Wood- 

 cock against a normal background, but with its obliterative shading variously 

 upset. In Fig. 24A, the bird is on its side, with its back toward the spectator. 

 Thus the largest expanse of its pattern is exposed to view, yet it completely 

 fails to obliterate, chiefly because it is no longer aided by a proper light-and- 

 shade gradation. Fig. 24B shows the same bird with under instead of upper 

 side exposed — in which position it is of course even more conspicuous. Fig. 



33 



