BRITISH WARBLERS
the throat of the performer, but is uttered in a jerky manner, giving one the impression of a number of short sentences with a full-stop at the end of each one, and of considerable effort in commencing each new sentence. Notwithstanding this peculiarity, their vocal powers may be said to have reached a very high degree of development. To my mind their song possesses an element of cheerfulness, due to some extent, no doubt, to pleasant associations, and the tone possesses a peculiar metallic ring which is not present in a similar degree in the song of other birds with which I am acquainted. When the males first arrive their song is persistent, but after incubation has commenced it is not uttered so frequently, and ultimately it is to a large extent limited to the spasmodic outbursts referred to. In addition to the song there are numerous call notes, some of which are very similar to and difficult to distinguish from those of the Sedge Warbler. It is possible to distinguish three distinct calls; the call-note proper used frequently by both sexes during the mating period, and also when the young are being attended to; the scolding note peculiar to the assemblies; and a harsh note uttered two or three times in succession, apparently as an expression of anger or annoyance, since it is usually the forerunner of much fluttering and clicking of bills. But the most interesting part of their vocal development is undoubtedly the power of imitation, which, when first heard, seems to equal that of the Blackcap or Marsh Warbler. In reality, however, the bird is not so finished an imitator as these other two species; for whereas the Blackcap will produce part or whole of the song of another species in so perfect a manner as to deceive the human ear, the Eeed Warbler does not seem to be capable of doing so. Its imitative faculty is generally limited to reproducing the call notes and cries of various species inhabiting the same neighbourhood, but some are undoubtedly produced from memory. I have heard a male, inhabiting some reeds surrounding an inland sheet of water, imitating the cry of the
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