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, motmots, 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 (Icterine) 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 
