144 AFRICAN GAME ANIMALS 



females, and sometimes as regards the adult males at cer- 

 tain seasons. There are some birds with what at first 

 glance does not appear to be a concealing coloration, which 

 nevertheless does really help in their concealment. The 

 hoopoo, for instance, crouching flat, with crest laid back 

 and wings partly outspread, obviously gains help from its 

 coloration in escaping the observation of hawks. Night- 

 hawks squatted on the ground in the daytime, whippoor- 

 wills on limbs, hen-pheasants, quail, and grouse on their 

 nests, many bay-birds or shore-snipe crouched on the beach, 

 desert-larks, and chats on the sand, ducklings and young 

 plovers, gulls, skimmers, avocets and stilts, female ducks, 

 and male ducks at moulting time, are among the many 

 birds which profit by, and by their habits show that either 

 dehberately or instinctively they purposely profit by, their 

 coloration. 



It would at first seem as if in these cases the conceal- 

 ing coloration must have arisen through natural selection, 

 especially when we see the concealingly colored individ- 

 uals taking advantage of their coloration by crouching 

 motionless, and the individuals of an advertising color- 

 ation making no effort to hide; compare, for instance, 

 desert-grouse, larks, and chats, and young skimmers, and 

 stilts, and moulting moor-fowl, with black and white spurred 

 plover, black and white chats, adult skimmers and stilts, 

 and black cock in the fall. But more careful study and 

 consideration make it appear probable that the minute 

 patterns in these cases have not been produced by natural 

 selection; that natural selection has merely perpetuated 

 the general scheme of a useful pattern, which has been 

 produced by some other cause. 



