Page:The British Warblers A History with Problems of Their Lives - 4 of 9.djvu/67

 have one common explanation, it would, in my opinion, be more in keeping with our present knowledge of the facts to regard them solely as an expression of varying emotional states.

Towards the end of July both young and old unite with the small flocks of Willow Warblers. Whitethroats, and Chiffchaffs, which roam about the hedgerows and small fields of potatoes. Both sexes have at this time a very dilapidated appearance, due to moulting, which commences about the second week in this month and extends throughout the greater part of August. As this moulting period proceeds, their vitality seems to increase, and when it is completed and the plumage again fully developed, they become exceedingly playful and lively.

As in the case of the Blackcaps, there is no better place to study them, during the last few weeks before they leave this country, than among the elder bushes. Here they come in search of food, and here they have full scope for their exuberant spirits. At this time of year they are far more noisy than during the early spring or summer, not that they sing, for any attempt they make in this direction has little or no resemblance to their true song, but that they are frequently uttering their call note, which is harsher than the one used in the spring, and bears so much resemblance to the corresponding note of the Blackcap at this period that it is sometimes most difficult to distinguish between them. The elder bushes during the first few hours of daylight are often full of them, together with Blackcaps, and thus there is frequently considerable commotion. The Blackcaps appear to be afraid of their pugnacity, and more often than not retire from their presence, which is not to be wondered at when one sees the rapid manner in which they dart in and out of the bushes, and the threatening attitude they assume. It is difficult to tell, from time to time, whether love of play or pugnacity is really the cause; I am inclined to think the former, for they