On several occasions this year (1910) I have listened with unalloyed pleasure to the sweet blackbird-like song of the grey-winged ouzel (Merula boulboul) at Naini Tal--a station in the Himalayas, consisting of over a hundred bungalows dotted on the well-wooded hillsides that tower 1200 feet above a mountain lake that is itself 6000 feet above the level of the sea. On the northern slope of one of the mountains on the north side of the Naini Tal lake, is a deep ravine, through which runs a little stream. The sides of the ravine are covered with trees--mainly rhododendron, oak, and holly.
On July 1st I went 1000 feet down this ravine to visit the nest of a spotted forktail (Henicurus maculatus) which I had discovered a week previously. Having duly inspected the blind, naked, newly-hatched forktails, I went farther down the stream to try to see something of a pair of red-billed blue magpies (Urocissa occipitalis).
The magpies were not at home that afternoon, and while waiting for them I caught sight of a bird among the foliage lower down the hill. At first I took this for a Himalayan whistling-thrush. I followed its movements through my field-glasses, and saw it alight on part of the gnarled and twisted trunk of a rhododendron tree. Closer inspection showed that the bird was a grey-winged ouzel. He had apparently caught sight of me, for his whole attitude was that of a suspicious bird with a nest in the vicinity. He remained motionless for several minutes.
As I watched him a ray of sunlight penetrated the thick foliage and fell upon the part of the tree where he was standing, and revealed to me that he was on the edge of a cunningly-placed nest.
The trunk of the rhododendron tree bifurcated about 20 feet above the ground; one limb grew nearly upright, the other almost horizontally for a few feet, and then broke up into five branches, or, rather, gave off four upwardly-directed branches, each as thick as a man's wrist, and then continued its horizontal direction, greatly diminished in size.
The four upwardly-directed branches took various directions, each being considerably twisted, and one actually curling round its neighbour. At the junction of the various branches lay the nest, resting on the flat surface, much as a large, shallow pill-box might rest in the half-closed palm of the hand of a man whose fingers were rugged and twisted with years of hard toil.
The upper part of the trunk was covered by a thick growth of green moss, and from it two or three ferns sprang.
As the exterior of the nest consisted entirely of green moss, it blended perfectly with its surroundings. From below it could not possibly have been seen. When I caught sight of it I was standing above it at the top of the ravine, and even then I should probably have missed seeing it, had not that ray of sunlight fallen on the nest and imparted a golden tint to the fawn-coloured plumage of the nestlings which almost completely filled the nest cup.
The situation of this nest may be said to be typical, although cases are on record of the nursery being placed on the ground at the root of a tree, or on the ledge of a rock. Many ouzels' nests are placed on the stumps of pollard trees, and in such cases the shoots which grow out of the stump often serve to hide the nest from view. The nests built by grey-winged ouzels vary considerably in structure. The commonest form is that of a massive cup, composed exteriorly of moss and lined with dry grass, a layer of mud being inserted between the moss and the grass lining. This mud layer does not invariably occur.
The cock ouzel remained for fully five minutes with one eye on me, and then flew off. I seized the opportunity to approach nearer the nest, and took up a position on the hillside level with it, at a distance of about 14 feet.
In a few minutes the hen bird appeared. Her prevailing hue is reddish brown, while the cock is black all over, save for some large patches of dark grey on the wings. In each sex the bill and legs are reddish yellow, the bill being the more brightly coloured. The hen caught sight of me and beat a hurried retreat, without approaching the nest.
The young ouzels kept very still; occasionally one of them would half raise its head. That was almost the only movement I noticed.
Presently the cock appeared, with his beak full of caterpillars. He alighted on a branch a few feet from the nest, where he caught sight of me; but instead of flying off as the hen had done, he held his ground and fixed his eye on me, no doubt swearing inwardly, but no audible sound escaped him.
Whenever I have watched a pair of birds feeding their young, I have almost invariably noticed that one of them is far more alarmed at my presence than the other. The ouzels proved no exception to the rule. In this case it was the cock who showed himself the bolder spirit. He remained watching me for fully ten minutes, his legs and body as immobile as those of a statue, but he occasionally turned his head to one side in order to obtain a better view of me; and I could then see, outlined against the sky, the wriggling forms of several caterpillars hanging from his bill. I hoped that he would pluck up courage to feed his youngsters before my eyes; but his heart failed him, for presently he flew to another tree a little farther away, whence he again contemplated me. After this he kept changing his position, never uttering a sound, and always retaining hold of the beakful of caterpillars. After a little the hen returned with her bill full of caterpillars, but she did not venture within 75 feet of the nest. I was not permitted to observe how long it would take the parental instinct to overcome the natural timidity of the birds. The sky suddenly became overcast, and a few minutes later I found myself enveloped in what the Scotch call a "wet mist." At certain seasons of the year rain storms come up as unexpectedly in the Himalayas as they do in the Grampians.
The rain put a final end to my observations on that nest, as I had to leave Naini Tal on the following day--an event which caused more sorrow to me than to the ouzels!