Chapter II 
BIRDS’ NESTS AND EGGS 
A CAREFUL examination of a bird’s nest will convince any one 
that it is a work of art. One cannot help wondering at the in- 
genuity displayed by its architect. How carefully a bird adapts 
itself to environment is well illustrated by endless examples : the 
red-winged blackbirds (whose nests are usually built among 
reeds, flags, or bushes) make their nests very much deeper when 
the place selected is subject to strong winds than in more shel- 
tered spots ; and then, as a further safeguard, the mouth of the 
nest contracts so that the eggs will not fall out when the flags are 
swayed by the wind. These clever birds have even been known 
to place their eggs in a deserted woodpecker’s nest in places where 
the fish crows were numerous—for the fish crow is worse even 
than the jay as an egg and fledgling thief. In this way the red- 
wings managed to elude their persecutors and saved their eggs 
and young from destruction. 
Some birds readily avail themselves of new and favourable 
conditions. The phoebe formerly built its nest exclusively on 
rocks, but now that houses and bridges are to be found through- 
out the country, this bird has to a great extent changed its former 
custom, and it now builds nests on aimost any sort of structure 
erected by man. This also applies to the barn swallow, while the 
chimney swift has taken possession of our chimneys, and almost 
forsaken the hollow tree-trunks, in which, but a few years ago, 
they built in large colonies. 
How rapidly birds are changing their habits is not known, 
but it is evident from the few examples we have about us that a 
change is progressing, in some cases very noticeably. 
Of course a bird’s main idea when depositing its eggs is that 
they shall be safe from enemies of all kinds and from unfavourable 
weather conditions. With these objects in view it is interesting to 
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