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 environrhent 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 almost 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 depositLig 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 



II 



