Page:The British Warblers A History with Problems of Their Lives - 3 of 9.djvu/65

 down, it is difficult to see why the young, when they have so many more opportunities of hearing other species in preference to their own, should sing true to type at all. If it is, therefore, true that in a large number of instances the song could not have been passed on from parent to offspring, it is à fortioria fortiori [sic] true of the imitations which are so essentially a part of the song.

(4) It may seem out of place to allude to emulation under the heading of song, forming, as it does, a small part of a much larger question; but since it has been remarked upon in connection with this species, a brief allusion to it is necessary.

It is no uncommon sight to see the male Blackcaps and Garden-Warblers engaged apparently in a singing contest. They settle within a few yards of one another, and exert themselves to the utmost in simultaneously producing sounds, which are by no means always tuneful. The same scenes occur between Nightingales and Blackcaps, and even between the three species, Blackcaps, Nightingales, and Garden-Warblers. At such times a Nightingale, while singing hurriedly, will pursue a Blackcap. This action may be interpreted as the result of a jealous rivalry, but when we see how prone the Blackcap is to excitement, resulting in the curious assemblies previously referred to, and the similarity of his song, no matter how different the cause of the excitement may be, we must not be too hasty in assuming that an intelligent appreciation of his powers is in any way connected with it.

Their food is a mixture of various fruits and insects. On their arrival in the spring they subsist principally upon the berries of the common climbing ivy (Hedera helix), and their bills and throats are often stained with the black juice. They swallow six or more at a time, large and small, and it is surprising how very large a berry they are capable of swallowing