SLENDER FOUNDATIONS 



Twigs and earth would not be well adapted to such 

 conditions, so we find that the building materials generally 

 used are much the same as those employed by shrikes and 

 woodcock. There used to be another bird in this country 

 that had similar nesting habits. It was known as Savi's 

 Warbler (Locustella luscinoides\ and not very many years ago 

 it was a constant inhabitant of the Cambridgeshire fens; 

 but drainage has destroyed its favourite haunts, and you 

 would be fortunate indeed if you were to come across a 

 specimen nowadays. 



Although the materials for its nest are the same, the 

 Reed Warbler sets to work in a manner very different from 

 those birds we have just mentioned, so perhaps you would 

 like to hear about it. Suppose we take as an example the 

 Great Reed Warbler or Reed Thrush (Acrocephalus arundina- 

 ceus\ a bird which is common enough on the Continent, 

 though it does not often pay a visit to our country. 



In building its nest the reed thrush has to take great care 

 to fasten it quite securely to its support, because the eggs 

 would sink if they were to fall into the water, and the young 

 birds too, not being provided with webbed feet, are unable 

 to swim. Now the nest itself weighs fully two ounces, and 

 when it contains the hen bird with her five eggs that weight 

 is more than doubled. When the young fledglings are 

 almost big enough to leave the nest the whole mass that has 

 to be supported may amount to as much as three-quarters of 

 a pound far more than any single reed could be expected 

 to carry! So the very first thing the bird has to do is 

 to find at least three reeds which grow at about equal 

 distances apart, and in such a way that they may support the 

 nest at three or more points of its circumference. That, 

 however, is not enough ; the reeds are all the better for the 

 purpose if they have leaves which form a fork with the stem, 



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