BRITISH WARBLERS
in the nature of a game. The fighting generally takes place within, comparatively speaking, a very small area. The owner of the territory is the aggressor, and he pursues the intruder, flying round and round in and out of the bushes, never leaving him alone for long, but incessantly attacking, and thus compelling him to move from place to place. Both males sing or warble continuously even as they fly, and when they meet there is considerable pecking and fluttering. As might be expected the attitudes are expressive of great excitement. When settled near one another, or in the same bush, a quivering of the wings is at times noticeable; but during the height of the excitement the feathers on their backs are raised, those on their heads erected, and their tails spread and drooped, or more frequently waved up and down. When less in earnest the attitudes are very similar, although the one male can by no means be said to intrude upon, but only to follow, the other, and at such a time an incessant excited warbling is uttered by both of them in addition to the usual fluffing of the feathers, spreading and waving of the tail. Therefore, it will be seen that, so far as the attitudes are concerned, there is little, if any, difference between the quarrel on the one hand and the companionship on the other, but that there is a genuine difference no one after closely observing them would, I think, deny.
The males have periods of frenzied excitement even before the arrival of the females, and I have seen a male commence to construct a nest, adding to it slowly day by day, which, upon the arrival of a female, was completed, and ultimately used for rearing the offspring.
The females begin to arrive about twelve days after the first male, and there is as much variation in their plumage as in that of the males. In some cases it is fully developed and brightly coloured, in others the reverse; but I believe that the brightly coloured females are of less frequent occurrence than the brightly coloured males.
As a rule the male pairs with the first female that enters
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