Chap. XV.] COLOR AND NIDIFICATION. 161 



In regard to birds which huild 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 rays of the sun ; " so that it is no valid objection 

 to his view that many birds having both sexes obscurely 

 coloi'ed build concealed nests.'* The female Horn-bills 

 [JBuceros), for instance, of India and Africa are protected, 

 during nidification, with extraordinary care, for the male 

 plasters up the hole in which the female sits on her eggs, 

 and leaves only a small orifice through which he feeds 

 her ; she is thus kept a close prisoner during the whole 

 period of incubation; '^ yet female hornbills are not more 

 conspicuously colored than many other birds of equal size 

 which build open nests. It is a more serious objection to 

 Mr. Wallace's view, as is admitted by him, that in some 

 few groups the males are brilliantly colored and the fe- 

 males obscure, and yet the latter hatch their eggs in 

 domed nests. This is the case with the Grallinte of Aus- 

 tralia, the Superb Warblers (Maluridfe) of the same conn- 

 try, the Sun-birds (Nectarinije), and with several of the 

 Australian Honey-suckers or Meliphagidse." 



If we look to the birds of England we shall see that 

 there is no close and general relation between the colors 

 of the female and the nature of the nest constructed by 



" 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, than during cool, 

 cloudy, or rainy weather. 



'* I may specify, as instances of obscurely- colored birds building 

 concealed nests, the species belonging to eight Australian genera, de- 

 scribed in Gould's ' Hand-book of the Birds of Australia,' vol. i. pp. 340, 

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



'^ Jerdon, 'Birds of India,' vol. i. p. 244. 



'^ On the nidification and colors of these latter species, see Gould's 

 ' Hand-book,' etc., vol. i. pp. 504, 527. 



