116 MIMICRY, AND OTHER PROTECTIVE 



It is also an ascertained fact, that the females are 

 more bold and pugnacious than the males. A further 

 confimation of this view is to be found in the fact 

 (not hitherto noticed) that in a large majority of the 

 cases in which bright colours exist in both sexes incu- 

 bation takes place in a dark hole or in a dome-shaped 

 nest. Female kingfishers are often equally brilliant 

 with the male, and they build in holes in banks. Bee- 

 eaters, trogons, motmotSj and toucans, all build in 

 holes, and in none is there any difference in the sexes, 

 although they are, without exception, showy birds. 

 Parrots build in holes in trees, and in the majority 

 of cases they present no marked sexual difference 

 tending to concealment of the female. Woodpeckers 

 are in the same category, since though the sexes often 

 differ in colour, the female is not generally less con- 

 spicuous than the male. Wagtails and titmice build 

 concealed nests, and the females are nearly as gay as 

 their mates. The female of the pretty Australian bird 

 Pardalotus punctatus, is very conspicuously spotted 

 on the upper surface, and it builds in a hole in the 

 ground. The gay-coloured hang-nests (Icterinse) and 

 the equally brilliant tanagers may be well contrasted; 

 for the former, concealed in their covered nests, pre- 

 sent little or no sexual difference of colour while the 

 open-nested tanagers have the females dull-coloured 

 and sometimes with almost protective tints. No doubt 

 there are many individual exceptions to the rule here 

 indicated, because many and various causes have com- 

 bined to determine both the colouration and the habits 



