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 surrounding 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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