WILLOW WARBLER 



the male supplying a great deal of the necessary food. With 

 the growth of the young these conditions alter, and about the 

 sixth day the necessity for a constant supply of food being 

 paramount both parents are consequently indefatigable in 

 searching for and bringing larvce to their hungry offspring. I 

 cannot recollect having seen a male brooding the young, 

 although he sometimes, for the purpose of cleaning the nest, 

 remains for a few moments in it after having actually delivered 

 up the food he was carrying. The fceces enclosed in a mem- 

 branous sac are carried away by the parents and eaten or 

 dropped some distance from the nest. For the first two days 

 or so the young develop slowly, but afterwards the growth 

 becomes more rapid. On the fourth day the primaries begin 

 to show and the eyes are partly unsealed. On the sixth day 

 the eyes, are fully open, and by the seventh the young are 

 active and make use of their call note, and the feathers on all 

 the feather tracts show colour. The primaries are about a 

 quarter of an inch long on the eighth day, down being still con- 

 spicuous on the head. By the eleventh or twelfth day the birds 

 are sufficiently fledged to be able to leave the nest and fly 

 moderately well, but for a while they remain on, or close to, 

 the ground, being unable to rise to any height or to grasp the 

 branches securely. Their strength, however, soon develops, 

 and they follow their parents, who now roam beyond the 

 boundaries of their territory, until able to find food for them- 

 selves. During July and August the males sing less and less, 

 ultimately becoming silent, but after the moult is finished 

 their plaintive song can again be heard occasionally until they 

 leave the country in August or September. 



In the life of the Chiff-chaff I remarked upon its peculiarly 

 inquisitive behaviour, and since the Willow Warbler is so 

 closely allied, it may w 7 ell be asked whether it too possesses a 

 similar trait. I can recall but little evidence pointing to its 

 presence, for although a Willow Warbler sometimes shows 

 excitement for no apparent reason at the presence of a member 

 of another species, yet it is difficult to recognise that constant 



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