time and labor in building, like those of the Woodpeckers and 

 Kingfishers. These nests are so well protected by their loca- 

 tion that they remain in good order and attract the same 

 birds or others to them for several years in succession. 

 There are some birds that prefer to repair and occupy the 

 deserted nests of other birds instead of building new ones for 

 themselves. Bluebirds and some of the Owls often do this, the 

 former taking empty Woodpeckers' holes, and the latter using 

 last year's nests of Crows and Hawks. 



The substances from which nests are constructed are 

 many; but every species of bird adheres quite closely to some 

 group of materials unless it is compelled to vary from them 

 for lack of supply. The most common materials used are 

 sticks, twigs, rootlets, chips, bark, leaves, hay, grass, stubble, 

 rushes, moss, lichens, clay, cloth, paper, string, feathers, down 

 and hair. The presence of one or more of these substances in 

 large quantities often reveals the species of the builder. Who 

 would not recognize the Robin's nest with its thick walls of 

 mud, or the Chippy's nest so thoroughly lined with hair, or the 

 English Sparrow's nest, that great mass of ragtags ? But the 

 nests of many birds are so similar in materials and manner of 

 construction that they cannot be identified unless the birds 

 which occupy them are seen also. There are some birds like 

 the Nighthawks that make no nests, but use a flat surface or a 

 slight depression to hold their eggs. 



Birds seem to aim at two things in nest-building: first, to 

 make their nests secure, and second, to hide them from their 

 enemies. They often fail in both particulars and the accidents 

 and tragedies that result are numberless. No Robin has the 

 wisdom to foresee that a prolonged summer-storm may dissolve 

 and wreck its nest when it is placed in the open, nor has the 

 Hummingbird the skill to deceive that highway robber of the 

 birds, the Red Squirrel. 



18 



