INTRODUCTION. XXV 
conspicuous in an open nest, and those of the latter are well adapted 
by their colour to harmonize with surrounding tints. If warmth is 
required in the one case, certainly it should be in the other also. Again, 
I have known the Wild Duck cover her eggs so completely as almost to 
defy detection, and that, too, long before she had commenced to sit, and 
when no warmth was required. I think, therefore, that there can be little 
doubt that it is solely from motives of concealment that these conspicuous 
eggs are covered. Stevenson, in his ‘ Birds of Norfolk’ (11. p. 417), also 
confirms this opinion, and says that (in the case of the Moorhen) the pre- 
caution of covering the eggs is more particularly adopted when the nest is 
in an exposed situation. 
“But we find many conspicuous eggs laid in bare open places that are not 
concealed in such a cunning manner. We can take as an instance the 
Short-eared Owl, who lays her white eggs on the open fens and marshes, 
or many of the Goatsuckers, who deposit their white eggs in flimsy open 
nests, or certain Ground-Pigeons (Geophaps) of Australia, who lay their 
buffish-white eggs on the bare ground. How are such eggs protected ? 
In this manner :—The plumage of all these birds is remarkably protective 
and assimilates very closely with the surroundings; moreover, they 
possess the habit of sitting very closely, conscious that they resemble the 
ground or branches and cannot readily be seen; and so they brood over 
their conspicuous eggs, shielding them by their sober plumage until 
almost trodden upon, ere they rise from them. We might also notice 
another rather puzzling instance belonging to this group, and that is 
to be found amongst the Pigeons. The nests of nearly all these birds 
are remarkably similar—platforms of twigs built in trees, rocks, or on the 
ground ; and the eggs are in all cases, so far as is known, white, or nearly 
so, and spotless. Pigeons’ nests are very slight and inconspicuous, and, as 
a rule, built in the dense cover ; moreover, the birds themselves are exces- 
sively wary. Again the very fact that these birds are so abundant and so 
widely spread over the world, notwithstanding their open nests and white 
eggs, is, in itself, strong evidence that these birds and their eggs are not 
much exposed to enemies or are well able to elude them, and also shows 
us how cautious we should be in looking upon such facts as serious objec- 
tions opposed to laws of nidification and colour. As an instance of how 
complex this subject is, we might take the great family of the Goatsuckers. 
Some of these birds (Aigotheles, or Owlet Nightjars of Australia) lay white 
eggs in holes of trees; others, as the Frog-mouths (Podargide), build a 
Pigeon-like nest on a branch and lay white eggs, depending for safety on 
the protective colours of their own plumage ; whilst the true Goatsuckers, 
of which our Common Nightjar may be taken as an example, lay eggs on 
the bare ground of protective tints, as well as depending on the sober colours 
of their plumage for safety. It remains now but to notice in this group 
VOL. II. c 
