Page:The British Warblers A History with Problems of Their Lives - 3 of 9.djvu/54

 hopped about, spreading his tail, waving his wings, singing and warbling, but was vigorously pursued by both parents.

In order to see whether the young are capable of recognising the note of their own parents. I have placed them on the ground or held them in my hand some distance from the nest, and in the territory of another pair. But hitherto I have been unable to obtain any satisfactory results; for it is necessary that one or other of the pair should use the note which exercises such influence on the young. The only reliable method would be to transfer a young one into the territory of a pair who had offspring of much the same size. The song of the male has little influence.

When the young have just left the nest the anxiety of the parents is even greater than before. They are now more or less scattered, and this is especially the case if their departure, on account of any alarm, has been a hurried one. If you happen to be near them the excitement of the parents is intense; but if by holding one in your hand, or even touching it, which is sometimes sufficient, you cause it to utter its alarm-note, this excitement apparently reaches its limit. There is little doubt that it is the limit, since the actions, especially in the case of the male, take the same form as at every other time of extreme excitement. Both parents utter unusually plaintive squeals, which gradually die away, and they flutter about on the ground; the male, hanging on a branch near you, twists and turns about, sometimes head downwards, flirting his tail, erecting his head feathers, and uttering notes which are impossible to describe. When the young are thus scattered it is interesting to notice the effect a certain note of the parents has upon them; their whole aim is to go in the direction of the sound, the attraction seeming almost irresistible. For the purpose of seeing the effect of this note, I have taken a young one when unable to fly, but only to scramble about among the branches, and having placed it upon the ground some distance away, have awaited the results. Its efforts to approach the sound were remarkable