The Zoologist/4th series, vol 2 (1898)/Issue 679/The Voice-registers of Birds

by Charles Adolphus Witchell

 

THE VOICE-REGISTERS OF BIRDS.

By Charles A. Witchell.

 

Musicians have distinguished several ranges of tone in human voices, and, with the object of rendering vocalization even and harmonious, teachers of singing have always laboured to smooth out these breaks or cracks in the voice. Although some teachers deny that these breaks are natural, and contend that they are due to a vitiated style of singing, the breaks are very noticeable in the passionate crying of a baby, and therefore must be considered as quite natural. The most distinct breaks in adult voices are to be found in basses and contraltos, whose deep song notes are widely different from their alto and soprano notes. The jodelling with which lads in the street sometimes amuse themselves very clearly illustrates this subject.

My present purpose is to draw attention to a seemingly analogous break in the voices of many birds. The subject is difficult to discuss, but not, I believe, devoid of scientific value. Perhaps the most obvious break in a bird-voice occurs in the Goose, whose discordant cries strongly suggest the first attempt of a person to play a clarionet. In man the upper register is merely the survival of the child's voice, but it is very difficult to determine whether the same survival of the infantile voice occurs in birds' songs, for half-grown birds rarely sing. It must at the same time be observed that the first songs of young Blackbirds and Thrushes are much like the high squeaky notes to which the voices of the adults often change abruptly from the full song.

In some birds we hear what may be termed the "chest voice" (corresponding, say, to our contralto and bass), and a "head voice" (analogous to our alto and soprano). The Blackbird affords the commonest instance. Its song consists of a few full whistled notes (the number increases as the season advances), never slurred from one to the other; and these, in every successive phrase, are immediately succeeded by some harsh squealing toneless notes, to which the voice breaks from the song. It is suggestive of what would be heard if one of our rich basses concluded every phrase by jodelling hysterically, like a Swiss. The same incident is very noticeable in the Mistle Thrush, whose very brief snatches of full-toned song (consisting of from two to four or five notes) are followed by a few high discordant sounds. In the Common Thrush this break hardly ever occurs as distinctly as in the Blackbird; but, whereas in the Blackbird the sounds are never given except after the full notes, in the Thrush they may constitute the entirety of several successive phrases; and this is especially the case when two Thrushes are about to fight.

In the Nightingale the terminal break in the voice is reduced to an occasional very brief high note. Bechstein observed this, and has carefully rendered it in a very good syllabification of the bird's song, from which the following is an extract:—

"Tio, tio, tio tix.
 Tzu, tzu, tzu tzi.
 Dzorre, dzorre, hi."

This little final note is never repeated or prolonged.

The Blackcap has distinct "falsetto" notes, which precede the full notes and never follow them. I have heard the Blackcap in September uttering a little song of the false notes, without any of the usual full notes.

The Lesser Whitethroat, like the Blackcap, commences its song with harsh notes; and the succeeding full tones, lacking the variety of the Blackcap's warble, are given at one pitch, and form a strain like that of the Cirl Bunting, but more musical.

In the Willow Wren there is a rapid succession of high notes at the beginning of the song, quite distinct from the immediately succeeding sweet full tones. The initial notes are given at about the same pitch. There is never one of these false or harsh notes at the end of the song.

The Robin and Starling seem not to revert to infantile cries in song, except that the former, in August and September, makes great use of the call-note and of the "distress-note," and sometimes forms brief phrases of these cries only. In September the young Thrushes twitter a good deal, but even at this season they sometimes utter full notes. In mid-September last I heard three Thrushes, near Eltham, singing a few very full notes. Similarly, early in October, near Stroud, a Blackbird was singing softly, but in a full deep voice; and in the middle of the month a Mistle Thrush near Eltham was singing very loud phrases of two notes each.

In the Finches the song generally follows a definite course in which several breaks of tone may occur, as in the Greenfinch and Linnet.

In the Yellow Bunting there are two high final notes quite distinct from the other part of the song, and never uttered except at the end of the song. Are they a survival or an acquisition?

I have no evidence that among wild birds the songs of the females have most resemblance to the immature warblings of the young. The female Starling, which I have often heard, sings in much the manner of her mate, but less loudly. In most races the infantile cries are abandoned as the birds approach maturity, as in the Columbidæ, whose squeaky notes are not heard from the adults. In the common Shellduck is a survival of the peeting, whistling cry of the young; while in other common Ducks this cry of infancy is lost when the birds attain their full size.