Book News and Reviews 



257 



patterns which, either in whole or in part, 

 either all the time in both sexes, or all the 

 time in one sex, or some of the time in one 

 sex, are advertising and not concealing. 

 This is also true of those birds of Africa 

 to which I paid attention, that is, the 

 Water Birds, the Bee-Eaters, Sunbirds, 

 and the like. Often the female is conceal- 

 ingly colored, or at least has a non-adver- 

 tising coloration, where the coloration of 

 the male is highly advertising. There are 

 large numbers of birds, including various 

 species of Woodpeckers, Crows, Black- 

 birds, Shrikes, Flycatchers, Swans, Peli- 

 cans, Herons, Cormorants, Gulls, Guille- 

 mots, Puffins and Hawks, which have in 

 both sexes, and all the time, a strongly 

 advertising coloration. In many other 

 birds the coloration may be advertising, 

 over the whole body, but only in one sex 

 and for part of the year. In yet others 

 the advertising coloration, temporary or 

 permanent, may be confined to one part of 

 the body, such as the breast or head. The 

 young birds may have a concealing color- 

 ation, even when the coloration of the 

 parents is at all times, including the most 

 critical moments of their lives, as when on 

 the nest, highly advertising (as examples, 

 take the Skimmers, Stilts, Terns, Gulls); 

 or they may have a coloration as revealing, 

 or almost as revealing, as that of the 

 parents; this being true of Pelicans, 

 Herons, Cormorants, and Anhingas, for 

 instance. 



"Among the Ducks, ordinarily, one sex 

 develops strongly advertising coloration 

 for almost all the year. The male Cardinal 

 has a strongly advertising coloration all 

 the year. The Tanager and Bobolink 

 have strongly advertising coloration pat- 

 terns for part of the year. There are 

 numerous other small birds possessing 

 highly advertising patterns of bodj' color- 

 ation. There are still larger numbers of 

 birds, including many Sparrows and most 

 Warblers, where the males, at least in 

 spring, possess a coloration which is highly 

 advertising on certain parts of the body, 

 usually the breast and around the head 

 and neck. Taking all these classes to- 

 gether, they make up very much more 



than a majority of American species, each 

 of which either all the time as regards both 

 sexes, or, as regards one sex, for all the 

 time or part of the time, are in whole or in 

 part advertisingly colored. In the semi- 

 arid West, for example, the male Lark 

 Bunting has a plumage pattern which is 

 advertising in its entirety, just as much so 

 as a Raven's; the male Longspurs possess 

 such an advertising pattern only on the 

 head, neck and breast; whereas, for in- 

 stance, the Baird Sparrow lacks it entirely, 

 both sexes being similar and both seeking 

 safety in actual physical concealment in 

 the grass. 



"(7) These advertising colors repre- 

 sent several different principles or ten- 

 dencies. As regards many of the Crows, 

 Woodpeckers and Blackbirds, it is evident 

 that in the development of the different 

 species, the tendencies, whatever they are, 

 that have made for a concealing coloration, 

 that is, for a coloration that would be in 

 harmony with the landscape and the im- 

 mediate surroundings of the birds, have 

 been completely overcome by other ten- 

 dencies that have acted with equal force 

 on both sexes, or, if not with equal force, 

 at least with sufficient force to make even 

 the female, though perhaps less brightly 

 colored, not concealingly colored. If, as 

 in the Red-headed Woodpecker, where 

 both sexes are alike, the bright coloration 

 of the male is due to sexual selection, then 

 either the same principle has been at work 

 as regards the female, or else some other 

 principle has affected both sexes in such a 

 way and with such strength as to com- 

 pletely overcome any tendency to pro- 

 duce a concealing coloration. In the case 

 of many Ducks and Tanagers, where, 

 unlike what is true of Ravens and Red- 

 headed Woodpeckers, there is a strong 

 sex difference, and where the male is 

 much more advertisingly colored than the 

 female, it is of course possible that the 

 principle, whatever it may be, which is 

 working for concealing coloration has been 

 powerful enough to overcome any other 

 tendencies as regards the female, but that 

 the principle of sexual selection (or what- 

 ever principle it is which so frequently 



