BRITISH WARBLERS 



momentarily deceived by its appearance, and but for the eggs 

 should have thought that the object of my search had been 

 achieved. Usually the nest is situated from two to four feet 

 above the ground, and it may be placed in any convenient 

 shelter such as bramble, dead bracken, elder and hazel 

 bushes, no partiality being shown for any particular kind of 

 undergrowth. 



From four to five eggs represent the normal clutch, and 

 on the average one egg is laid every twenty-four hours. 

 Whether the male shares the duties of incubation with the 

 female I cannot say, but it is probable that he does so. His 

 song, which had decreased to so large an extent during the 

 period of sexual activity, can now be heard more frequently. 

 The behaviour of the female when disturbed from her nest 

 deserves some attention. When one approaches the nest 

 or the young of the Blackcap too closely the parent or parents 

 become excited and manifest by their actions the intensity 

 of the emotion which is aroused. Now the Garden Warbler 

 is closely related to the Blackcap, and although the instincts 

 of the two species are, generally speaking, uniformly alike, 

 yet, as we have already seen, the emotional behaviour during 

 sexual activity differs both in regard to type and tone. This 

 difference extends to the emotion which accompanies the 

 parental instinct. It is by no means easy to evoke emotional 

 response in the Garden Warbler ; approach the nest quietly, 

 awake the bird rudely to the danger which threatens, and 

 the result is in most cases similar; it hurriedly deserts 

 and in a few moments is flitting uneasily amongst the sur- 

 rounding branches. Sometimes it flutters away and slowly 

 moves its partially expanded wings, and at other times 

 responds more actively by spreading its tail and rapidly 

 fluttering its wings. At no time, however, have I observed 

 its response approach the degree attained by the Blackcap 

 under similar circumstances, nor have I been successful in 

 making it flutter about the ground after the manner of that 

 species. The same individual does not always behave simi- 



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