GAY PLUMES AND DULL 



species of birds, in which the female is obscurely 

 marked, that build in holes and cavities, such as our 

 wrens, the great crested flycatcher, the European 

 starling, the English sparrow, the bush-tits of Cal- 

 ifornia, and the wood duck. The female oriole is 

 much duller-colored than her mate, yet she builds 

 a pocket nest. Of course these last cases do not 

 prove that there is not greater safety in a hidden 

 nest, they only show that the color of the mother 

 bird is not the main factor in the problem. But 

 that a bird in a hole is safer than a bird in an open 

 nest may well be doubted. The eggs are probably 

 more secure from the thievish crow and the blue 

 jay, but not from rats and squirrels and weasels. 

 I know that the nests of the bluebird and the chick- 

 adee are often broken up by some small enemy. 



We fancy that the birds are guided by their 

 instinct for protective colors in the materials they 

 choose for their nests. Most birds certainly aim 

 to conceal their nests — the solitary builders, but 

 not those that nest in communities, like the cliff 

 swallows and rooks and flamingoes — and the 

 materials they use favor this concealment. But 

 what other materials could they use ? They choose 

 the material everywhere near at hand, — moss, 

 leaves, dry grass, twigs, mud, and the like. The 

 ground-builders scrape together a few dry straws 

 and spears of grass; the tree-builders, twigs and 

 lichens and cotton and rootlets and other dry wood 

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