300 THE BIOLOGY OF BIRDS 



Feltwork Nests. — Some of the most beautiful nests are 

 of the fehwork type familiar in the case of chaffinch and gold- 

 finch. With a basis of interwoven fibres they may be lined 

 with hair or feathers, and disguised externally with moss 

 and lichens and spider's web. They are open in the two 

 finches named, domed in the wren and bottle titmouse, slung 

 like a hammock in gold-crest and oriole, suspended by a 

 string in certain grosbeaks and humming-birds. These 

 nests have two good qualities : they must be very com- 

 fortable and they are well camouflaged. In the nest of the 

 long-tailed-tit there is a feltwork of lichens, moss, wool, and 

 spiders' webs and a quilt-like lining of small feathers, whence 

 the name " feather-poke." It is an elongated oval with a 

 small doorway in the upper part of one side. A suggestion 

 of the labour involved in this elegant construction is given in 

 MacGillivray's record that he counted 2379 feathers in one 

 nest. 



Among the feltwork nests there are many individual 

 touches of great interest. Thus there is no doubt that the 

 light nest is sometimes weighted with lumps of clay. Certain 

 warblers (Aedon and Thamnobia) invariably place a piece of 

 snake's slough on their nest, like the horse-shoe above the 

 house-door. 



The Psychological Aspect, — Without further experiment 

 it is not possible to go far with the analysis of the bird's 

 behaviour in nest-making, (a) The theory that the bird 

 behaves as a Robinson Crusoe might do, who tried to build a 

 hut, never having seen one before, is extremely improbable. 

 In the first place, because the architecture of the nest is so 

 specific ; in the second place, because there is so little tentative- 

 ness or hesitation in the bird's behaviour. The behaviour of 

 the builders does not suggest the activity of intelligent artists 

 picking and choosing their material and testing its capacities. 



{h) Alfred Russel Wallace lent his great authority in 

 support of the view that intelligent utilisation of tradition 

 and models counts for much in the case of nest-building. 

 While a bird may inherit an indefinite tendency to use its 

 energies in this direction, how it builds and when it builds 



