WILLOW WARBLER 



not yet alluded is uttered at times of anxiety, or seemingly 

 for no ostensible reason. It is very similar to the correspond- 

 ing note of the Chiff-chaff, and very difficult to distinguish 

 therefrom, consisting of two notes uttered in a plaintive key, 

 but more slowly or rather not so briskly as those of the other 

 bird. 



Their food is similar to that of the Chiff-chaff, and consists 

 almost entirely of insects. Occasionally they peck at the fruit 

 in gardens, and can often be found in the autumn in the 

 elder bushes, but I do not recollect having seen them actually 

 feeding on the berries. Their principal food when they arrive 

 consists of the various species of Chironomida ; these they 

 seek for diligently, examining large and small branches, buds, 

 and leaves. Since they are later than the Chiff-chaff in 

 arriving at their breeding grounds, they probably do not suffer 

 so much jfrom scarcity of food brought about by abnormal 

 climatic conditions. Nevertheless they are compelled some- 

 times to face frost and even snow, and they then lapse into 

 silence, less able apparently to withstand the cold, or more 

 probably less capable of replacing their usual diet by more 

 minute and hardy insects. Later in the season larva form 

 their staple diet, especially those of the oak-leaf roller moth 

 {Tortrix viridana). The young are principally fed on larva. 



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