( 122 ) NOTES AND OBSERVATIONS ON THE NESTING OF THE BULLFINCH.

Transcription

1 ( 122 ) NOTES AND OBSERVATIONS ON THE NESTING OF THE BULLFINCH. BY FRANCES PITT. DURTNG June and July, 1918, I established intimate relations with two pairs of Bullfinches (Pyrrhula p. pileala) which nested within a few yards of each other in a young spruce and larch plantation. Both pairs exhibited the usual partiality of their species for deep shade, placing their nests against the main stem of particularly thick young spruces at about four feet from the ground. The first nest was discovered on May 3rd, and was then apparently ready for eggs ; in fact, the first egg must have been laid very shortly afterwards, for on the 7th it held three, typical Bullfinch eggs, exquisite dainty things with their purple-brown blotches on a very pale blue ground. Quite different were the eggs of the second nest (found on May 19th, the bird having then begun to sit), which were like those of a Linnet, the blue being less pure, approaching greenish-grey in hue, and the markings a fainter purple. Both nests conformed to the usual type, being made of small dried spruce twigs and lined with fine roots and hair. It was on May 19th that having put up a hiding tent, I made an attempt to take some photographs of the birds belonging to the first nest. Having cleared away a few of the overshadowing branches, and arranged my camera, I settled down to wait. Hardly had I made myself comfortable than there was a twittering in the bushes and there was the hen coming back, escorted by the cock. Such a dainty quakcrish little person in pearl-grey, black and white. She appeared surprised to find the surroundings so altered, and looked about, then into the nest, turned and went away, but immediately hopped back and stood on the side of the nest and looked in again. All the time her handsome mate was standing behind her, resplendent with his salmon-pink breast. He twittered to her all the time as if beseeching her to settle down on the egg without more delay (by " twittering " I do not mean the piping call-note, which I never heard used at the nest, but only when the birds had left it, but a very faint subdued sound). In a few seconds the female Bullfinch did settle down, slipping lightly on to her eggs, whereupon the cock flew off, leaving her brooding peacefully in the warm stillness of the fir plantation, while Thrushes, Blackcaps, and Garden-Warblers poured forth continuous song, hover-flies buzzing a drowsy accompaniment in the quiet air.

2 The male Bullfinch arrives at the nest with his throat distended with food. (Photographed by Miss F. PITT.)

3 124 BRITISH BIRDS. [VOL XII. Having exposed a plate, I waited some time to change it> but when I did so unfortunately shook the camera, which frightened the hen off the nest. She disappeared into the heavy shadows among the spruces and no more was seen of her for half an hour, at the end of which time I left the tent for a while. Returning at * I found it hotter than ever, the flies droned more drowsily than before, Pigeons were cooing sleepily, and only the different Warblers seemed to sing energetically. I had hardly got into my " hide " before I heard first a twitter and then the plaintive piping call-note of the Bullfinches. Soon the hen came fluttering by the tent and without hesitation went on to the nest. I exposed a plate, and then clapped my hands, intending to drive her off before changing the slide. To my astonishment she would not move. Make as much noise as I would, I could not induce her to stir t She sat through it all without winking, but when I tried to change the plate the slight shaking of the tent front frightened her more than all my noise. She was gone in a second, In a little while, during which I heard a great deal of conversation going on in the melancholy Bullfinch language in the surrounding trees, she and her mate came back together. Shepopped on to the eggs and he stood by her for some minutes, I subsequently found that he always escorted her back to the nest, being the most attentive and devoted of mates. The young hatched on May 23rd, and the 24th being a bright day 1 took my camera to the tent to try for some more photographs. The little ones were very small and helpless, decorated with tufts of black down like the conventional adornments of a circus clown. Are such tufts merely an accident of evolution, or do they serve a useful purpose? Watching the tiny mites as they lay in their nest gave me no answer to my query, unless it was the thought that maybe these scanty tufts are a legacy from the primitive bird in which the nest-building impulse was not yet developed, and whose young therefore would almost certainly be well clad. Hardly was I. inside the tent before the female Bullfinch was back at the nest escorted by the male. Having seen her settled down he left at 1.30, returning fifteen minutes later with his throat swollen with food. She opened her beak, and regurgitating his store, he gave it all to her. At 2.0 he was back again, and once more he fed her. He then stopped away until This time, the hen having taken a little food from her mate, rose, stepped back to the edge of the nest, and left the young ones exposed to view. The cock, leaning forward, * Normal (Greenwich) Time, not Summer Time is used throughout this paper.

4 VOL. xii.] NESTING OF BULLFINCH. 125 fed the mites with the remainder of his food supply, after which he attended to the sanitation of the nest, passing some of the excrement to the female to swallow and disposing of the rest himself, after which he went off to forage again, and the hen settled down to brood. At 3.0 she became restless, looked this way and that, and finally slipped of! the nest and away through the bushes. Hardly had she gone when the male Bullfinch appeared with food. His "taken aback" look when he found she had disappeared was quite laughable : however, he fed and attended to the young before flying off in the same direction in which she had vanished, and I took the opportunity of their being both away to leave the " hide." Evidently when the young are first hatched the cock bird does all the catering, supplying both his mate and the young with food at intervals varying from fifteen minutes up to thirty-five or more. I noted the next day that the female, though she left the nest twice, did not bring food with her on her return, while her mate arrived each time with his throat swollen with the results of his foraging. My notes for the afternoon run : (J brought food at 1.4? went off at 1.22 and returned without food 1.33 o brought supplies at 1.55 The pair left together at 1.57 $ returned without food at 2.19 cj came with food at 2.25 Left tent at 3.10 I further noted down as the birds unfolded their family life before my eyes that : " The cock is a perfect little gentleman, feeding his mate most daintily. He gives her some food first, then she rises off the young ones and stands aside, while he feeds them, after which she gives them what she has received. Then both attend to the sanitation. The regurgitated food appears to be semi-digested buds, etc., but it is impossible to say for certain. The cock does look a quaint little fellow when he comes home with his throat as full as it is possible to cram it! He is really the daintiest and gayest of feathered creatures, with his salmon-pink waistcoat, grey back, white rump, and coal-black tail, but if he is a gay cavalier in his bright clothes, his mate might be a Puritan dame in her demure greys, whites, and blacks. Curiously inconsistent are their flat, somewhat hawk-like heads and strong, thick bills each tims I look at them they make me

5 Female Bullfinch waiting with open beak for a share of the male's supplies. (Photographed by Miss F. PITT.)

6 VOL. XII.] NESTING OF BULLFINCH. 127 think of the wall paintings of the hawk-headed gods on ancient Egyptian monuments! " Photographically the situation of the nest was very bad, it being impossible to open it up sufficiently to permit an instantaneous exposure. Dark Austrian pines and spruce surrounded the place, and the light which filtered through the heavy green branches was even poorer actinically than it appeared to the eye. In consequence I had to give short time exposures, varying from J of a second up to two or three, when the hen was brooding. To begin with, the slight click of the shutter would cause both birds to " freeze " for a moment, but later they became so indifferent to all sounds that not even shouting would make them turn their heads! They also lost all fear of movements within the tent. I could shake it as much as I liked and they took no notice, but they did not get reconciled to the sight of a human being. If I showed no more than my hand outside the tent they were both gone in an instant. The result of this acquired indifference to noise was a dreadful wastage of plates. Again and again I tried for records of various episodes of the family life, only to find on development that the photographs showed too much movement to be any use at all. I never got a good photograph of the old birds removing excrement, an incident I tried for repeatedly. For the first day or two after the young had hatched, it was swallowed at the nest by the parents. Afterwards they carried it off and, I believe, dropped it at a distance. The first time I saw the female Bullfinch bring food for the family was on May 29th, when I began my watch at My notes, made while I waited, run as follows : " Very hot, the air full of drowsily humming flies, a few birds singing, a hen Cuckoo bubbling and her mate cuckooing. An Owl rouses himself to hoot vigorously, at which a Blackbird or two break into hysterical shrieks. The young Bullfinches seem much distressed by the heat and lie gasping all the time with their heads over the edge of the nest. They have grown enormously, almost doubling in size during the last two days. The female returns (11.18), feeds (the first time I have seen her do so) and covers them. She too seems very hot, notwithstanding that the nest is more or less shaded, and sits gasping with her beak open. The male, who has seen her home, has now gone off with a beakhil of excrement. At the cock appears with food. Both attend to the young and the two leave together. At they both return, the male with food, the female without. The cock seems this

7 128 BRITISH BIRDS. [VOL. SH. time to have difficulty in regurgitating his supplies and eventually flies away looking bilious. The hen, having covered the young for a moment or two, flies after him, almost upsetting one of the little things out of the nest as she rises. " At <J and $ return together, both bringing food. Each feeds the young, then the ben opens her beak, exactly as if expecting the cock to give her food, and he helps himself several times to her supply, giving a little to each of the nestlings. He then leaves, and she broods the little things for a few moments. Then she pulls a fibre out of the nest, which appears to have got out of place, and flies away with it. At 1.23 the female appears alone, feeds the famity, and broods them until her mate's return at When he has fed and attended to them, the two depart together. At 2.15 they are back again, but do not stop after feeding the young and cleaning up. Leave tent at 2.20." From this time forward the pair invariably foraged together, returning together with their supplies, and behaved, in fact, like a most devoted couple. Except when the hen stayed to brood the young for a while, the cock never moved without her. They each had their own path by which they approached the nest. He invariably flew on to the roof of my tent and thence to a particular twig in front of the nest, but she came from the back, slipping quietly through the branches and appearing suddenly on the further side of the nest. Sometimes the pair notified their approach with their mournful call-notes, and at other times came silently. I only once saw the male take food from the female, but several times saw him share supplies with her. She would stand with open beak mutely appealing to him, but more often than not her supplicating attitude was disregarded. After the first six days the parental duties were shared equally, both as regards feeding and carrying off excreta. The visits, which to begin with were at fifteen to twenty minute intervals, got further and further apart until, by the time the young were ready to fly, food was only brought once in three-quarters of an hour or even longer. The result of the young being left so long was that the nest sometimes got dirty, but the old birds when they did turn up always cleaned it carefully. The young grew with extraordinary rapidity, and on May 30th, when they were seven days old, I noted : " The nestlings grow like mushrooms: they seem to have doubled in size in the night. They can now hold their heads right up in the air. When they do so, with their great blind eyes and long

8 Female Bullfinch at the nest, the male being just out of sight. (Photographed by Miss F. PITT.)

9 180 BRITISH BIRDS. [VOL. xu. trembling necks, they are grotesquely reptilian in appearance. Their clown-like tufts of down add to their weird appearance." They were much distressed by heat, not only by the direct rays of the sun, but when shaded as well, and I repeatedly saw them lying with heads over the edge of the nest panting in great distress. It seems therefore as if the partiality for nesting in evergreen bushes on the part of this species is really due to its seeking cool, dark sites, such as the hearts of these trees usually afford. How rapidly the young developed may be gathered from the fact that on the eighth day their feathers were showing, and I wrote that " though comparatively helpless yet, their eye-slits only beginning to open, they have already some idea of trying to preen themselves. One made a valiant attempt on the young stumpy feathers that are appearing on its shoulder, but failing in the effort, yawned widely and settled down to doze until the old birds came home." At eleven days old the young had altered wonderfully, they had doveloped many more feathers, their eyes had opened, they appeared to see and understand what was going on around them, and at the sight of the old birds or at the shaking of a twig they twittered in anticipation of the good things to come. Their beaks, already large, contrasted strongly with the intensely black ones of their parents, for at this stage they were a dirty yellowish-white. When fifteen days old they were fully fledged and the frail nest threatened to give way under its burden, for the five filled it to overflowing. The sixteenth day June 8th saw them launched into the world five little Bullfinches suddenly shot out of the nest; five pale greyish editions of their parents were seen for a few moments among the dark boughs; then the anxious call-notes of the old birds were heard, and they vanished for good. To recapitulate the results of my observations : the male fed the female while she was incubating, also brought her food after the young had hatched, and did the entire foraging for the family until they were six days old. For the remaining ten days the pair shared their duties, working together and seldom moving without one another. Further, the young were, to begin with, fed at fifteen to twenty minute intervals; but, later, the time lengthened until it became forty-five to sixty minutes and occasionally more. In both nests watched incubation occupied fourteen days: in the case of the first the young flew sixteen days after hatching; in that of the second on, I think, the fifteenth day, but it might possibly have been

10 VOL. XII.] NESTING OF BULLFINCH. 131 a day earlier. The accompanying table giyes dates and times : TIME-TABLE. 1st Nest 2nd Nest When found. Remarks. First egg. 3/V/18 Ready for eggs 19/V/18 Incubation begun 5/v (?) No. of eggs. 5 5 Bird began to sit. 9/V 18/V (?) Young hatched. Incubation. 23/V 1/VI days (?) Young left neat. 8/vi 16 days old 15/vi or 14/VI