Page:The British Warblers A History with Problems of Their Lives - 1 of 9.djvu/31

 the roots of the herbage, often hopping on to and along the ground in swampy places, where small worms and spiders are abundant, and since they generally inhabit swampy places, swamp-loving insects form a great portion of their food. It is common to see the adults hunting the willows and small alders (Alnus glutinosa), but never the high trees. The young in July when fully grown are not so particular in this respect, often searching in the tops of large alders, especially during the swarming time of the aphides. It is no doubt the pursuit of food that leads the adults into the middle of cornfields, but I have not been able to determine what the special food they are following consists of.

Flies belonging to the Chironomidæ, of which I have identified the following, are frequently taken: Chironomus viridis, Chironomus brevitibialis, and Tanypus choreus.

These insects can be seen, especially in the morning, both early and late in the season, clustering under the leaves of the willows, hazels and alders. A slight tap on the branches will frequently produce incredible numbers, where before few could be seen.

In June and July they feed, amongst other insects, on the following:—

The young, especially when still in the nest, are fed largely on these insects, occasionally also on the larvæ of certain moths and butterflies. During all the summer months great numbers of aphides are devoured, in fact, these insects appear to constitute the great food supply, not only of this species, but of many others also. A close inspection of the twigs and