516 THE DESCENT OF MAN. 



Mr. Wallace admits that with the king-crows (Dicruriis). 

 orioles, and Pittidae, the females are conspicuously colored, 

 yet build open nests; but he urges that the birds of the first 

 group are highly pugnacious and could defend themselves; 

 that those of the second group take extreme care in con- 

 cealing their open nests, but this does not invariably hold 

 good;* and that with the birds of the third group the 

 females are brightly colored, chiefly on the under surface. 

 Besides these cases, pigeons, which are sometimes brightly 

 and almost always conspicuously colored, and which are 

 notoriously liable to the attacks of birds of prey, offer a 

 serious exception to the rule, for they almost always build 

 open and exposed nests. In another large family, that of 

 the humming-birds, all the species build open nests, yet 

 with some of the most gorgeous species the sexes are alike; 

 and in the majority, the females, though less brilliant than 

 the males, are brightly colored. Nor can it be maintained 

 that all female humming - birds, which are brightly 

 colored, escape detection by their tints being green, for 

 some display on their upper surfaces red, blue and other 

 colors, t 



In regard to birds which build in holes or construct 

 domed nests, other advantages, as Mr. Wallace remarks, 

 besides concealment, are gained, such as shelter from the 

 rain, greater warmth, and in hot countries protection from 

 the sun;| so that it is no valid objection to his view that 

 many birds having both sexes obscurely colored build con- 

 cealed nests. The female horn-bill (Bticeros), for instance, 



* Jerdon, " Birds of India, ' vol. ii, p. 108. Gould's " Hand-book 

 to tlie Birds of Australia," vol. 1, p. 463. 



f For instance, the female Eupetomena macrotira has the head and 

 tail dark blue with reddish loins; the female Lampornis porphyru- 

 rus is blackish green on the upper surface, with the lores and sides 

 of the throat crimson; the female Eulampis jugularis has the top of 

 the head and back green, but the loins and the tail are crimson. 

 Many other instances of highly conspicuous females could be given. 

 See Mr. Gould's magnificent work on this family. 



X Mr. Salvin noticed in Guatemala (" Ibis," 1864, p. 375) that hum- 

 ming-birds were much more unwilling to leave their nests during 

 very hot weather, when the sun was shining brightly, as if their 

 e^gfi would be thus injured, than during cool, cloudy or rainy 

 weather. 



1 may specify, as instances of dull colored birds building con- 

 cealed nests, the species belonging to eight Australian genera 

 described in Gould's " Hand-book to the Birds of Australia," vol. i, 

 pp. 340, 362, 365, 383, 387, 389, 391, 414. 



