Page:The British Warblers A History with Problems of Their Lives - 2 of 9.djvu/31

 The migration of the females continues for about fourteen days, and this results in the nesting operations of certain pairs being temporarily in advance of those of others. In one case the courtship may be finished and the nest even built and lined ready to receive the eggs, while another male close at hand may still be without a mate; but in this latter case, when the female does at last arrive, the courtship is quickly finished and the nest, as I shall mention later, more rapidly built. Much time is therefore gained, and it will be found, in consequence, that there is ultimately little variation in the dates upon which the young of different pairs are hatched.

On their arrival the females seem to prefer the bottoms of the hedgerows, thick undergrowth, or low positions of some description to the taller trees; it is difficult to see the reason for this, especially as it is only the case on their arrival, but it may, to some extent, facilitate the courtship, which is immediately commenced.

As might be expected from such active and lively little creatures, the courtship is an exceedingly interesting and also a very beautiful one, and in order to see it at its best it must, as in the case of every bird, be watched during the first few hours of daylight; it may proceed to a limited extent during the daytime, but I have seen no sign of this, neither do I expect to do so, for all birds at this time of the year rest and are dull in the middle of the day, and although they become more active towards the evening, yet this activity cannot be compared with that which exists during the first few hours of daylight.

The female generally arrives during the night, and directly there is sufficient light the male in whose territory she has settled commences to court her. The duration of the courtship varies to suit the needs of each particular case; on the one hand, a pair may be courting in the mornings for some days, and, on the other, the differences are quickly settled, and they apply themselves to the task of nidification.