DOMED OR ROOFED NESTS 249 



As we remarked at the beginning of the present 

 chapter, the domed or roofed type of nest is an 

 especial feature in the architecture of Passerine birds. 

 These are mostly small and comparatively weak 

 and defenceless species, and unquestionably adopt 

 this style of nest as a safeguard from the exception- 

 ally numerous enemies that surround them, especially 

 in tropical countries. To a much smaller extent they 

 may be formed on this model for the purpose of 

 shielding their contents either from cold (as in the 

 case of some of the northern ranging species), or 

 from the torrential deluges of rain that are such a 

 feature of tropical latitudes. In a great many cases 

 it will have been remarked that the protection de- 

 rived from these bag - like nests is still further 

 ensured by the peculiarities of the situations that 

 have been selected for them, such as at the ex- 

 tremities of drooping slender branches, often above 

 water, where naught but winged enemies could reach 

 them. In like manner we have often seen how cun- 

 ningly they have been concealed amongst surrounding 

 vegetation, or made to resemble objects near them. 

 Another fact worthy of repetition here is the fre- 

 quency with which a species has occasionally adopted 

 a domed type of nest when built in an exceptional 

 position. Lastly, we have to call attention to the 

 fact that the eggs of these domed or roofed nest- 

 builders are, in a very large number of cases, white, 

 or of one tint, or rarely spotted to any great extent. 



