WILLOW WAEBLER 



morning of May 10th, noticing that a female was wing- 

 flapping and that the male was close beside her, I examined 

 the nest and was surprised to find the female sitting ; she 

 flattered off in fact at my approach. The mystery, however, 

 was soon explained, for the second female, the bird that was 

 excitedly flapping her wings on my arrival, was rapidly build- 

 ing a nest. This was situated in the centre of the territory, 

 about fifteen yards from the second nest of the first female. 

 Later on in the morning I noticed the male in the presence of 

 this second female excitedly wing-flapping, while the first 

 female was actually sitting on the nest. Throughout the 

 morning of May 11th the second female was occupied in 

 building, and by May 13th she had laid the first egg. The 

 full clutch of eggs was completed by May 19th, and on the 

 morning of that day I found that the eggs which were on the 

 point of hatching in the first female's second nest had been 

 taken. On May 21st the first female was again building 

 within a few feet of the footpath, this being her third nest, 

 and in it was deposited one malformed egg on May 29th, and 

 on June 9th she was building yet again, but this, her fourth 

 nest, was never completed, although sufficiently advanced to 

 allow of removal. The young were hatched in the second 

 female's nest on June 1st. The behaviour of these three birds 

 is interesting from more than one point of view. At the 

 outset we have the curious fact of the first female building two 

 nests, not taking into account the third and fourth ones which 

 were the result of the second being destroyed. Why should she 

 not have been content with the first nest ? Some birds, it is 

 true, commence one or even two nests before the final effort, 

 but I am not aware of this habit in the case of the Willow 

 Warbler. The position chosen for the first nest was at a con- 

 siderable distance from the footpath, and the female could not, 

 therefore, have been disturbed by passers-by. The actual 

 situation was in a bank close to the roots of a large beech 

 tree, where the soil was perfectly dry, and was consequently as 

 suitable a one as could possibly be found, but it was close to 



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