MORE SOLID STRUCTURES 



more or less of their stability to the use of animal sub- 

 stances, which have greater binding powers than grass, 

 straw, and the like. The Land-rail or Corn-crake (Crex 

 crex) makes a nest of dry herbage, stalks, and grass, on the 

 ground amidst growing corn or clover, or in a meadow ; 

 but here again the structure is a very loose affair. A better 

 architect and a more skilful builder is the Grasshopper 

 Warbler (I^ocustella ncevia\ that shy and vigilant little 

 summer visitor of ours, whose shrill chirping note is the 

 origin of its name. This bird and the Pied Wagtail 

 (Motacilla lugubris) build nests of coarse dry grass with finer 

 pieces within, the wagtail using also dead roots, moss, etc. 

 Birds generally prefer dry herbage and vegetation for their 

 nests, for it is not only finer and more supple, and therefore 

 easier to work with, than green leaves and stems, but also 

 far warmer and by no means so liable to decay. 



NESTS MADE OF VEGETABLE MATERIALS AND EARTH 



Among the song birds there are some that increase the 

 solidity of their nests by the addition of earth to the soft 

 vegetable materials of which they are otherwise composed. 

 The nests of the Blackbird (Turdus merula) and the Thrush 

 (Turdus musicus), well known to everybody, are of this kind. 

 Both birds excel in the art of working up earth or mud and 

 spreading it so that it forms a hard, smooth layer. Mixing 

 pieces of grass, etc., with the mud (just as a bricklayer mixes 

 hair with his mortar to make it " bind " better), disposing 

 these in a more or less circular direction yet in such a way 

 that the pieces cross one another and afterwards drying the 

 composition by the warmth of their body (which is about 

 109 F., or 10 higher than our own bodily temperature), 

 they succeed in constructing a cup which is at the same time 



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