BRITISH WARBLERS
behaviour of the male after the female has arrived I infer that this question is of importance, since he confines himself more or less to certain boundaries, and moreover possesses a headquarters, usually a prominent dead reed, to which he returns after following the female, and from which he pours forth his song.
Before the arrival of the females the song of the males can be heard in every direction throughout the day, though the "trills" are longer and the song more persistent in the morning and the evening. Climbing up some dead reed and sitting near the top the male utters his peculiar note, turning his head first in this direction and then in that, and thereby producing a similar ventriloquistic effect to the song of the closely allied Grasshopper Warbler. Perched thus on the top of some tall reed he is a conspicuous figure early in the season before the new reeds have attained to any considerable height, and where the species is plentiful there is consequently little difficulty in locating the males and watching their movements.
Upon the arrival of the females, excitement is considerable, and a great deal of restless movement then takes place. One can trace the quarrelling and pursuing, and observe without difficulty the general excitement reflexes inseparable from the behaviour of most species when the sexual instinct is dominant. What the direct stimulus to all this varied behaviour is I am unable to say without further detailed observation, a short description therefore of the behaviour of both sexes as it actually appeared to me must suffice under the circumstances.
The actions of both sexes during this period are very beautiful, and in many respects interesting, but especially so for the reason that they are identical with those of the Grasshopper Warbler at a corresponding period. The two species are closely related, and we might reasonably expect to find a similarity of behaviour, but it is a curious fact that identity of structure does not necessarily imply identity of emotional expression. The Chiff-chaff and Willow-Warbler, the Reed
4
