Our handsomest bird
One of the prettiest spots by the water was that very one where the spotted bird was accustomed to come, and I often went there at noon and sat for an hour on the grassy bank in the shade of the drumming-tree. The river was but thirty to forty feet wide at that spot, with masses of water forget-me-not growing on the opposite bank, clearly reflected in the sherry-coloured sunlit current below. The trees were mostly oaks, in the young vivid green of early June foliage. And one day when the sky, seen through that fresh foliage, was without a stain of vapour in its pure azure, when the wood was full of clear sunlight—so clear that silken spider webs, thirty or forty feet high in the oaks, were visible as shining red and blue and purple lines—the bird, after drumming high above my head, flew to an oak tree just before me, and clinging vertically to the bark on the high part of the trunk, remained there motionless for some time. His statuesque attitude, as he sat with his head thrown well back, the light glinting on his hard polished feathers, black and white and crimson, the setting in which he appeared of greenest translucent leaves and hoary bark and open sunlit space, all together made him seem not only our handsomest woodpecker, but our most beautiful bird. I had seen him at his best, and sitting there motionless amid the wind-fluttered leaves, he was like a bird-figure carved from some beautiful vari-coloured stone.
The most interesting events in animal life observed at this spot relate to the cuckoo in the spring of 1900. Some time before this Dr. Alfred Russel Wallace said, in the course of a talk we had, that he very much wanted me to find out exactly what happened in a nest in which a young cuckoo was hatched. It was, I replied, an old, old story—what could I see, supposing I was lucky enough to find a nest where I could observe it properly, more than Jenner, Hancock, Mrs. Hugh Blackburn, and perhaps other writers, had told us? Yes, it was an old story, he said, and he wanted it told again by someone else. People had lately been discrediting Jenner's account, and as to the other chief authority I had named, one writer, a Dr. Creighton, had said, "As for artists like Mrs. Blackburn, they can draw what they please—all out of their own brains: we can't trust them, or such as them." Sober-minded naturalists had come to regard the habit and abnormal strength attributed to the newly-hatched cuckoo as "not proven" or quite incredible; thus Seebohm had said, "One feels inclined to class these narratives with the equally well-authenticated stories of ghosts and other apparitions which abound."
Since my conversation with Dr. Wallace we have had more of these strange narratives—the fables and ghost stories which the unbelievers are compelled in the end to accept—and all that Dr. Jenner or his assistant saw others have seen, and some observers have even taken snapshots of the young cuckoo in the act of ejecting his fellow-nestling. But it appears from all the accounts which I have so far read, that in every case the observer was impatient and interfered in the business by touching and irritating the young cuckoo, by putting eggs and other objects on his back, and by making other experiments. In the instance I am about to give there was no interference by me or by the others who at intervals watched with me.
A cuckoo in a robin's nest
A robin's nest with three robin's eggs and one of the cuckoo was found in a low bank at the side of the small orchard on 19th May, 1900. The bird was incubating, and on the afternoon of 27th May the cuckoo hatched out. Unfortunately I did not know how long incubation had been going on before the 19th, but from the fact that the cuckoo was first out, it seems probable that the parasite has this further advantage of coming first from the shell. Long ago I found that this was so in the case of the parasitical troupials of the genus Molothrus in South America.
I kept a close watch on the nest for the rest of that afternoon and the whole of the following day (the 28th), during which the young cuckoo was lying in the bottom of the nest, helpless as a piece of jelly with a little life in it, and with just strength enough in his neck to lift his head and open his mouth; and then, after a second or two, the wavering head would drop again. At eight o'clock next morning (29th), I found that one robin had come out of the shell, and one egg had been ejected and was lying a few inches below the nest on the sloping bank. Yet the young cuckoo still appeared a weak, helpless, jelly-like creature, as on the previous day. But he had increased greatly in size. I believe that in forty-eight hours from the time of hatching he had quite doubled his bulk, and had grown darker, his naked skin being of a bluish-black colour. The robin, thirty or more hours younger, was little more than half his size, and had a pale, pinkish-yellow skin, thinly clothed with a long black down. The cuckoo occupied the middle of the deep, cup-shaped nest, and his broad back, hollow in the middle, formed a sort of false bottom; but there was a small space between the bird's sides and the nest, and in this space or interstice the one unhatched egg that still remained and the young robin were lying.
During this day (29th) I observed that the pressure of the egg and young robin against his sides irritated the cuckoo: he was continually moving, jerking and wriggling his lumpish body this way and that, as if to get away from the contact. At intervals this irritation would reach its culminating point, and a series of mechanical movements would begin, all working blindly but as surely towards the end as if some devilish intelligence animated the seemingly helpless infant parasite.
Of the two objects in the nest the unhatched egg irritated him the most. The young robin was soft, it yielded when pressed, and could be made somehow to fit into the interstice; but the hard, round shell, pressing against him like a pebble, was torture to him, and at intervals became unendurable. Then would come that magical change in him, when he seemed all at once to become possessed of a preternatural power and intelligence, and then the blind struggle down in the nest would begin. And after each struggle—each round it might be called—the cuckoo would fall back again and lie in a state of collapse, as if the mysterious virtue had gone out of him. But in a very short time the pressure on his side would begin again to annoy him, then to torment him, and at last he would be wrought up to a fresh effort. Thus in a space of eight minutes I saw him struggle four separate times, with a period of collapse after each, to get rid of the robin's egg; and each struggle involved a long series of movements on his part. On each of these occasions the egg was pushed or carried up to the wrong or upper side of the nest, with the result that when the bird jerked the egg from him it rolled back into the bottom of the nest. The statement is therefore erroneous that the cuckoo knows at which side to throw the egg out. Of course he knows nothing, and, as a fact, he tries to throw the egg up as often as down the slope.