s a protection to the birds and young. But, as
a matter of fact, they do protect from attack, for hawks or crows do not
pluck such nests to pieces, as in doing so they would be exposed to the
attack of the whole colony; whereas a hawk or falcon could carry off a
sitting-bird or the young at a swoop, and entirely avoid attack.
Moreover, each kind of covered nest is doubtless directed against the
attacks of the most dangerous enemies of the species, the purse-like
nests, often a yard long, suspended from the extremity of thin twigs,
being useful against the attacks of snakes, which, if they attempted to
enter them, would be easily made to lose their hold and fall to the
ground. Such birds as jays, crows, magpies, hawks, and other birds of
prey, have also been urged as an exception; but these are all aggressive
birds, able to protect themselves, and thus do not need any special
protection for their females during nidification. Some birds which build
in covered nests are comparatively dull coloured, like many of the
weaver birds, but in others the colours are more showy, and in all the
sexes are alike; so that none of these are in any way opposed to the
rule. The golden orioles have, however, been adduced as a decided
exception, since the females are showy and build in an open nest. But
even here the females are less brilliant than the males, and are
sometimes greenish or olivaceous on the upper surface; while they very
carefully conceal their nests among dense foliage, and the male is
sufficiently watchful and pugnacious to drive off most intruders.

On the other hand, how remarkable it is that the only small and brightly
coloured birds of our own country in which the male and female are
alike--the tits and starlings--either build in holes or construct
covered nests; while the beautiful hangnests (Icteridae) of South
America, which always build covered or purse-shaped nests, are equally
showy in both sexes, in striking contrast with the chatterers and
tanagers of the same country, whose females are invariably less
conspicuous than the males. On a rough estimate, there are about 1200
species of birds in the class of showy males and females, with concealed
nidification; while there are probably, from an equally rough estimate,
about the same number in the contrasted class of showy males and dull
females, with open nests. This will leave the great bulk of known birds
in the classes of those which are more or less protectively