BRITISH WARBLERS
When fully grown the young ones are soon taught to find food for themselves. They follow their parents amongst the bushes and undergrowth, each being fed in turn, but occasionally taking the trouble to pick off a few aphides for themselves, giving one the impression that they prefer to be lazy as long as possible. Their difficulty no doubt lies in their want of experience, and consequent lack of power to distinguish between what is food and what is not; thus, even when they have left their parents. I have seen them in doubt trying to swallow the ragged ends of a broken twig. They are very playful at this age, their games sometimes taking the form of a tilting match. Three take part, two sit on convenient twigs facing one another, and the third from his central position might almost be called an umpire. Numbers one and two then lower their heads, each in anticipation of the other moving; one of them, call him number one, then springs into the air, and darts at number two; number two dodges and occupies the position vacated by number one, each of them then face round ready to continue the fray, the change of positions becoming quite rapid.
Although I have never found a second brood, yet I think it probable that two are sometimes reared, for this reason, that some of the males in July indulge in a second courtship. When a female is present the male will spread out his wings and tail, and walk sideways up and down a branch, the female for her part also spreading out her wings and tail, but not moving up and down the branch. After performing thus for a short time she will fly off, pursued by the male, calling to him with her low quiet note if he does not immediately follow. Sometimes two or three males join in the pursuit, apparently for the fun of the thing and the annoyance of the real lover.
It will be seen that this courtship is really identical with that performed in spring, and is therefore somewhat of a mystery, the more so as it is not indulged in by all males, for
10
