Page:The British Warblers A History with Problems of Their Lives - 2 of 9.djvu/27

 acquiring the same area. During the first week in April I have seen these struggles commenced at daylight and carried on intermittently for two or three hours. The demeanour of the combatants, when not actually fighting or pursuing one another, shows the state of excitement they are in, for their wings are jerked about and their song is spasmodic. When actually pursuing one another their flight is extremely rapid, the birds darting in and out of the trees and bushes, sometimes high up in the tops, at other times low down amongst the brambles, and when finally they do meet, their bills click as they collide with one another, and they tumble about in the air; then, for a time, there is a pause and they retire a distance from one another. And now it is that their excitement is so apparent: it seems as if they were keeping their passions controlled with considerable difficulty.

This demarcation of their territory is best seen in long, narrow, wooded banks, which are known to be inhabited by different males; here the boundaries can be watched with greater ease. In some cases it is almost possible to draw an imaginary line, across which neither male, whose territories are adjoining, will trespass; in other cases there is a small intervening space between two territories, which again is not hunted by either male.

But in every case I have found these boundaries adhered to with the most amazing precision. Each male also appears to have some suitable position in his territory—a dead tree or perhaps some prominent larch—which he uses as his headquarters, and from which he makes little excursions into the different parts of his territory, always, however, returning sooner or later to this central position. He is therefore sometimes at one end of his territory, sometimes at the other, feeding as he travels amongst the bushes and branches of the different trees, at one moment in the tops of the highest, then low down amongst the brambles, and again on the ground, along which he moves by a succession of bounds.

Now it frequently happens that two males on adjoining