The Zoologist/4th series, vol 2 (1898)/Issue 683/Notes on the Breeding of the Chaffinch

by Charles Adolphus Witchell

 

NOTES ON THE BREEDING OF THE CHAFFINCH.

By Charles A. Witchell.

 

Some years ago, a friend who had bred many hybrid Finches of different kinds told me that hybrids could not be obtained from the Chaffinch, because that bird would not breed in confinement, a flight being necessary for the union of the sexes. This information, and the frequent exhibition of a swooping flight by a pair of Chaffinches, led me to conclude that the swooping flight might be really necessary to the breeding of the Chaffinch; and it may be mentioned that Mr. W.H. Yale, in his 'Handbook of Hybrid Birds' (1896), records that he has not been able to find an authentic instance of a Chaffinch mule.

My present purpose is to offer some remarks on the question whether a love-flight is necessary to the Chaffinch. By "love-flight" I do not mean the common straight Cuckoo-like flight of the male when he is leading a female from tree to tree, and flying with a constant and even succession of wing-beats; but I mean the swooping flight performed by both birds together, in which they are very near each other, if not actually in contact.

During this swooping, the birds always utter the call-note which they particularly address to each other and to their young. It is a little soft sound, something like "chirri" pronounced very rapidly. In April and May this note may be constantly heard. But during the love-flight another sound is sometimes uttered, and this deserves very close attention. Perhaps the simplest mode of describing it will be to give a few instances of its occurrence.

On April 5th, 1896, a pair of Chaffinches near each other in an Austrian pine in a garden at Stroud, in which tree the species nests nearly every season, were uttering the love-call, "chirri."

They suddenly darted forth and swooped and swerved close together, both of them uttering the call many times; and during the flight the whole song was given by one of the birds (doubtless the male), but in a hurried manner, ending in a very full low rattle, seemingly lower in pitch than the usual termination of the song. At that moment the birds had descended to within a foot or so of the ground, and were so close together that they seemed almost as one. They did not separate until, after swerving upward, they had again descended and actually entered a thick pink-may bush. Throughout the incident they were never more than twenty yards distant from me.

On April 19th, near New Eltham (Kent), a male and female Chaffinch were uttering their call-note nearly overhead in an oak. They quitted the tree at the same time and swooped close together, passing within two yards of my head, and swerved up again into another tree, They were squeaking their call all the time, and during the flight, but at a moment when the birds were behind me one of them uttered a brief repetition of a full low note, precisely like the low gurgling rattle which was uttered on a similar occasion by the above-mentioned Chaffinch at Stroud.

On April 20th, at a spot a quarter of a mile from the site of what occurred on the 19th (above described), two Chaffinches were calling in an elm tree. The female was shivering her wings and repeating the love-call very rapidly. A few yards distant from her a male was hopping from twig to twig, exclaiming in the same manner. Both birds swooped, and during the flight the low rattling cry was uttered exactly as it was yesterday. The low rattle is not always heard.

On May 11th two Chaffinches swooped downwards together when passing from tree to tree, and during some portion of the descent they were very close together, breast to breast. They were all the time uttering the "chirri" very rapidly. One was certainly a female, and the other seemed to be a male. The foliage interfered with the view.

On May 12th a pair of Chaffinches descended together from the top of an oak, swerved up again nearly to the full height of the tree (forty feet) and descended as before, uttering the callnote all the while.

I have sometimes seen Chaffinches treading in a tree. The male then alights several times in succession on the female, meanwhile uttering the "chirri"; and at the last attempt, when about to quit the female, he utters the low full rattling note above mentioned, and immediately quits her and makes no further attempt for some time. It appears therefore that this full cry accompanies the act of coition, and, if so, it is important if the note is sometimes heard when the two sexes are swooping together. It seems to imply that coition may actually occur in the air.

The full rattle is also deserving of observation in relation to the song of the bird, for the greater part of the song is of much the same character as this exclamation; and it is probable that if this full sound had been originally employed during coition, it might have been afterwards employed for the purposes of suggestion, and in course of time might have been elaborated into a comparatively long strain. I venture to think that ornithologists will allow that I have elsewhere ('Evolution of Bird- Song') adduced some reasons for the theory of the development of certain songs (as well as certain alarms) from a repetition of short cries, and the song of the Chaffinch is not without indications of a similar history.

Dr. Butler tells me that the song of the Chaffinch is popularly rendered—

"In another month will come a Wheatear."

The first few notes never show much variation, and in early spring they may sometimes be heard in the form of mere repetitions of the "chirri." The middle of the song consists of a rattling repetition of the same character as the full rattle I have just described. The last syllables, "wheatear," have always seemed to me to be very interesting, as relating the song of the Chaffinch to those of the Greenfinch and Lesser Bedpoll. The "wheat" is greatly varied in loudness, and is very often wholly absent, or its place is occupied by a sound like "tissi."

Near Eltham, in April and May, some of the male Chaffinches have a loud single alarm-cry, "zee," which can be heard through all the chorus of birds. This note is sometimes given in the song, but only at one particular part. It then takes the place of the hard penultimate note, "wheat," and whenever given it ends the strain. I called the attention of Mr. A. Holte Macpherson to this note, and he, like myself, had never heard it elsewhere. It seems to me to be a survival from an earlier period. The Chaffinch seems to be losing all trace of this danger-cry, and to be developing instead the full love-rattle. The "chirri," and the "love-rattle," and the "zee," uttered in succession, would constitute an excellent "skeleton" of the Chaffinch's song, and especially so if the first two cries were each repeated a few times.