The Zoologist/4th series, vol 5 (1901)/Issue 720/On the Wintering Singing of the Song-Thrush (''Turdus musicus''), Fowler

by William Warde Fowler

 

ON THE WINTER SINGING OF THE SONG-THRUSH
(TURDUS MUSICUS).

By W. Warde Fowler, M.A.

 

Towards the middle of last November I was struck, like many others, by the vociferous singing of Song-Thrushes; they were unusually numerous, and almost every individual seemed to be uttering some kind of song, and continuing it more or less from early morning, when the voicefulness was at its highest point, till sunset, and even later. At the same time it happened that there came into my hands an interesting work on the song of birds by Dr. V. Häcker, of Freiburg-in-Breisgau, in which I found some useful remarks on the autumn and winter singing of birds, which seemed to point to the desirability of further close observation out of doors. I was then living close to the Park at Oxford, and was in the habit of going out daily before breakfast, as well as of crossing the Park two or three times a day on my way to and from college; and I determined to note down each day throughout the winter what birds I heard singing, and especially to record the voicefulness of the Song-Thrush. This I continued to do until the middle of March. My chief object was to ascertain, if possible, whether the great outburst of song which I had noticed was psychologically connected with the breeding season, or should be reckoned by itself as merely the expression of bodily comfort, arising from abundance of food and a mild temperature.^[1] I wished to know how long it would go on without interruption—whether there would be any considerable break before the true spring song began, and, if so, how far it would be due to a change of temperature. I did not, as will be seen, arrive at any very definite conclusions, but I hope to be able to continue observing with more certain result in future winters.

In the ' Zoologist' for 1894, pp. 410, foll., Mr. O.V. Aplin had a short paper in which he clearly distinguished the autumn song of some birds—e.g. the Robin and the Chiffchaff (i.e. the song resumed after the moult, often feeble and imperfect)—from the winter song, which in some cases begins in November, and continues more or less regularly till breeding begins: this winter song (if I understood him rightly) he regarded as undoubtedly the beginning of the spring or breeding song. Dr. Häcker does not express himself quite so decidedly, and, on the whole, he seems disposed to take a different view: and as his remarks are interesting in several ways, and are the result (as he tells us in his preface) of twenty years' observation, I take leave to translate them here ('Der Gesang der Vögel,' p. 52):—

"In the renewal of song in autumn, when the Robin (Erythacus rubecula), the Blackbird (Turdus merula), and the Chiffchaff (Phyllopneuste rufa) are conspicuous, we have to do, in distinction from the summer song, exclusively with a kind of voice-play (Spielstimmung), as Darwin pointed out; in fact, with a psychical condition, which, for example, is to be found in adult dogs, which delight in play, and invite their masters to join them.

"The same holds good in part for those birds which, in the middle of winter—i.e. long before the beginning of the breeding season—let us hear their song. To these belong the Wren (Troglodytes parvulus), whose breeding falls in April, and the Dipper (Cinclus aquaticus), which normally has its first brood in April, and its second in June. Here we have to do with birds which are exceptionally robust, and whose perfect adaptability to a winter climate is plain from the fact that here at least (i.e. in Breisgau) they are true residents with a limited winter range. A few hours of winter sunshine is enough to produce in these birds that increase of bodily and psychical comfort which leads to the use of voice-play.

"I have attempted above to explain the meaning of the different sexual cries in connection with the preservation of the species. Only in a few cases—namely, in those of the autumn and winter song of a few resident species—are we unable to assign to song a positive importance for the preservation of species or individual. But the caution needed in dealing with these negative instances is well shown by the example of the Crossbill. It is common to quote this bird as an example of abnormal habit in the physiological sense, since it usually pairs and sings in December and January, breeds in February, and hatches its young in March. Naumann has already pointed out the meaning of this: the bird performs the work of propagation and rearing precisely in the months in which its chief food, the cones of pines, are at their ripest and best, so that the parent birds find it then easiest not only to feed themselves, but to supply their young with the seeds which they convey to them in their crops."

It will be seen from this passage that Dr. Häcker, like Mr. Aplin, clearly separates the true autumn song, heard after the moult, from the winter song which often begins in November; and with this conclusion most field ornithologists will probably agree. As to the meaning of the winter song, he is not so clear; apparently he takes it as in part "voice-play," the result of abundant food and bodily comfort, and as having no immediate connection with breeding, but adds a useful caution suggested by the case of the Crossbill. My observations of last winter, so far as they go, seem to support both his explanation and his warning.

It was on November 17th, a very uncomfortably chilly day, that I first made a note of the great number of Thrushes in song. No doubt Central and Southern England had been visited by a large immigration from the north and east. It was dull, moist weather, chilly rather than cold, and unusually still. I am convinced, though I cannot prove it, that not only old males, but young birds, and even females, were using their voices to swell the chorus: every bird seemed to be making some sort of noise, and there was every variety of performance, from the full, clear utterance of the practised singer to the harsh and wheezy notes of the novice or the female. As I have already said, this vocal activity continued in full swing, without apparent diminution of the numbers, until December 8th, when I left Oxford for the Christmas vacation, the weather all the time being mild and damp. I did not observe any distinct sign of courting or sexual activity.

After leaving Oxford, I was at Kingham, in the north-west of the county, until January 18th, and continued my notes there. When I arrived the singing was still going on, and I was told that it had attracted notice, as elsewhere. It continued in full strength till the 15th. From that day till January 3rd, in rather colder weather, varied by warm days and cold fog, I heard occasional singing only, as one ordinarily does in mid-winter; on December 20th, 25th, 28th, 31st, which were stormy days, the birds were silent, and left the field vacant for the Mistle-Thrush. Though there were plenty of Song-Thrushes still to be seen, as well as occasionally heard, I think there was a decided diminution in the numbers during the last half of the month. From January 3rd to January 21st, with the temperature varying at 9 a.m. from 25° to 42°, I failed to detect the voice of a single bird of this species.

It may be useful to exhibit the diminution of song between December 15th and January 3rd in the form of a table:—

Dec.⁠15. Therm.⁠38°. Dull and damp. Not many Thrushes singing.
⁠„⁠16.⁠„⁠42.⁠Fine. Not many songs.
⁠„⁠17.⁠„⁠42.⁠Feels colder and drier. Very few songs.
⁠„⁠18.⁠„⁠45.⁠Open and mild. Few songs.
⁠„⁠19.⁠„⁠33.⁠Very fine. Much singing, including Mistle-Thrush.
⁠„⁠20.⁠„⁠46.⁠Strong gale from south. Only Mistle-Thrush singing.
⁠„⁠21.⁠„⁠38.⁠Fine. Several Thrushes singing.
⁠„⁠22.⁠„⁠28.⁠Fine and frosty. Two Thrushes sang.
⁠„⁠23.⁠„⁠25.⁠Cold fog. One Thrush sang.
⁠„⁠24.⁠„⁠30.⁠Very cold dense fog. One Thrush sang at 9.30.
⁠„⁠25.⁠„⁠52.⁠Warm and drizzly, with wind. Mistle-Thrush only.
⁠„⁠26.⁠„⁠42.⁠Soft day after rain. One Thrush sang after sunset.
⁠„⁠27.⁠„⁠45.⁠Wet and rough. Two or three Thrushes sang.
⁠„⁠28.⁠„⁠45.⁠Heavy gale from west. Not a voice.
⁠„⁠29.⁠„⁠30.⁠Very fine. No Thrushes sang.
⁠„⁠30.⁠„⁠40.⁠Dull and drizzly. Heard one Thrush.
⁠„⁠31.⁠„⁠38.⁠Great gale. No birds singing.
⁠Jan.⁠1.⁠„⁠35.⁠Cold rain. One or two Thrushes sang.
⁠„⁠2.⁠„⁠28.⁠Fine and sunny. One Thrush sang.

On January 3rd a short period of cold and foggy weather set in, with one heavy fall of snow. I heard no Thrush during this cold weather, nor during the very rapid thaw of the 9th and 10th; nor did two fine days, the 14th and 15th, which brought out the love-note of the Blue-Tit, and all but induced the Chaffinch to begin, stimulate our Thrushes to start their song again, I returned to Oxford on the 18th, a warm, damp day (therm. 42°), where I found many birds full of voice, but not the Thrushes. On the 21st, however, with the temperature 45°, and a feeling of spring in the air, there was a general awakening, and this continued till the 29th, when another spell of cold began, and, in spite of one or two fine days, silence prevailed. On February 4th (therm. 28°), a cold but still day, they sang again freely; and from this time onward may be said to have continued in song, with occasional interruptions, but never in the same numbers, or with the same noisy vociferation, as in the autumn.

The conclusions to be drawn from these observations are not altogether clear to me; but I may venture upon a few remarks on them.

First, as to the general conditions of voicefulness, I think it may be safely said that you will not hear the Song-Thrush in strong wind, nor snow, cold fog, or other uncomfortable wintry weather. What really spurs them to sing is still, open weather, when food is easy to get at: sunshine is not a necessity, and the temperature is of no great account until it becomes really low, and continues so for some days. For example, on March 25th, when I was writing these notes, a bitterly cold day of snowstorms, a Thrush was singing finely at 6.45 p.m., with the thermometer at 26°.

Secondly, as regards the meaning of winter song, and its possible connection with breeding, the entire silence of this species between January 3rd and January 21st might suggest a distinction between a winter song, stimulated only by the enjoyment of food and bodily comfort, and the true spring or breeding song. I do not, however, feel by any means sure that such a distinction is to be drawn, without modification; I am inclined to think that the great outbreak of song in the autumn was, in the case of mature birds at least, a forecast of the coming breeding-season. This species is an early breeder, and eggs have been found as early as February 28th^[2]: and the silence in January might have been accidental, or have occurred at another time, according to the weather, just as it may also sometimes be noticed in April or May. Birds that have already lived through one or more breeding-seasons must, I should imagine, have come to associate the full vocal powers they have acquired with the joys and duties of that time, and may revert to it by association of ideas when they are well-fed and comfortable in November and December. But the majority of the singers of last autumn—immigrants, birds of the year, and females—were very possibly using their voices only in what Dr. Häcker has called "voice-play." Thus, if by any chance I am right, there is a twofold element in the winter song of this species; but further observations may be expected to correct or modify a conclusion which I only advance with hesitation.

It may be as well to add that in the North of England the Song-Thrush does not seem to be a familiar winter singer, no doubt owing to the southward migration of this species in the autumn. I am never myself in the north during the winter, and have to rely on the evidence of others; but I find Waterton, in his characteristic essay on the Stormcock, describing the latter bird as "cheering us with his melody during the dreary months of winter when the Throstle and the Lark are silent." Lately Mr. E.P. Butterfield, of Wilsden, near Bradford, in the natural history column of the 'Yorkshire Weekly Post' (Dec. 29th, 1900), asked "whether any of your readers have heard the Song-Thrush in full song in Yorkshire in December"; and added that he himself had not, even in the most favourable season.

I add a few notes about the winter singing of our two other common Thrushes, the Mistle-Thrush and the Blackbird. The former bird is a curiously irregular singer, and in his habit of singing in the face of a strong wind he stands alone. I did not notice him this year till December 19th, and it is in December, I think, that his voice is most conspicuous. That the mid-winter singing of this species is the beginning of the spring or breeding song is almost certain; for he is a very early breeder, and is rarely in difficulties for food to support his vigorous vitality. Like the Crossbill, he finds much of his favourite food in perfection in December and January—viz. the berries of the ivy, yew, mistletoe, &c.

As regards the Blackbird, it is worth noting that, in the passage translated above, Dr. Häcker mentions this species as regularly singing after the moult (i.e. in September) at Freiburg-in-Breisgau; and Gilbert White says the same of the Selborne Blackbirds (letter xl. to Pennant, and letter ii. to Barrington).

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1. On this disputed question see Darwin, 'Descent of Man,' ii., 51 foll.; Wallace, 'Darwinism,' 384; W.P. Pycraft, Story of Bird-life,' p. 93, foll.; the writer's 'Summer Studies,' ch. vi; and references to German views will be found in Häcker. 'Der Gesang der Vögel,' p. 29, foll.
2. H. Saunders, 'Manual of British Birds,' p. 4 (2nd edition).