The Nature and Characteristics of Sub-song

AVICULTURALISTS and bird fanciers have long used the term "recording" to denote the quiet "practice-like" singing so often heard from their pet birds before they come into the phase of true song. It has often been asserted that the instrument known as the Recorder originally took its name from the bird flageolet which was used by bird fanciers for teaching tunes to Canaries (Serinus canarius), Bullfinches (Pyrrhula pyrrhula) and other song birds, but we are indebted to R. Thurston Dar t for a recent reference (Trowell, 1957) which shows that this is in fact improbable; it seems more likely that the bird song was named from the instrument—as indeed Daines Barrington (1773) supposed. Early aviculturalists must have noted from time to time the utterance by birds in the wild of sounds similar to their "recordi n g " and there is no doubt that many of the early naturalists (for example, Daines Barrington) refer in their writings to sub-song, either as " record ing" or without giving it a definite name. E. M. Nicholson has reminded us of Gilbert Whi te ' s mention of the contrast between " the Blackcap's loud and wild p ipe" and its "sweet but inward melody" and Miss E. M. Barraud has given us the reference in Charles Darwin 's Descent of Man: "The first attempts to sing 'may be compared to the imperfect endeavour in a child to babble' . The young males continue practising, or as the bird-catchers say, ' recording' , for ten or eleven months. Their first essays show hardly a rudiment of the future song ; but as they grow older we can perceive what they are aiming a t ; and at last they are said ' to sing their song round" ' (mainly quoted by Darwin from Daines Barrington). As far as we are aware, Nicholson (1927) was the first to employ the term "sub-song" , and in 1931 (p. 61) he gave a number of suggestions aimed at helping field naturalists to observe and keep notes of important variations in pattern and intensity of song. The use of the term was later developed by Nicholson and Koch (1936) simply to mean "quiet song"—that is, song of low volume. It was taken to include "all performances which are so inwardly or faintly uttered that they do not carry to anywhere near the distance over which the bird is physically capable of making itself heard" . Nicholson alone adds that it has no territorial influence and provokes no visible hostility in other males. Obviously this use of the term does not imply that there is