(489) Heteroxenicus nipalensis nipalensis (Hodgs.).
THE NEPAL SHORT-TAILED CHAT.
Heteroxenicus nipalensis nipalensis, Fauna B. I., Birds, 2nd ed. vol. ii, p. 19.
This Chat is spread throughout the Himalayas from Sikkim and Nepal to Eastern and Southern Assam and thence through the Chin Hills and Arrakan Yomas to Tenasserim.
Pershouse found a bird of this species breeding in the Bhamo Hills but, as no specimens were obtained, we cannot say to which race it belonged.
In Sikkim Stevens gives its breeding elevation as between 4,700 and 7,000 feet but says that in North Assam it occurs, probably in Winter only, right down to the foot-hills or even in the plains. In South Assam we found it breeding abundantly at all elevations above 3,000 feet up to the highest peaks, probably up to 8,000 feet. Osmaston also took a nest near Darjiling at about the latter height.
Although an odd nest may be taken now and then in scrub-jungle, especially in deserted cultivation surrounded by forest, or even in bamboo-jungle, this little Chat normally breeds in dense damp forest with plentiful green undergrowth. Like many other birds, it affects little open spaces, the banks of streams and similar spots more often than the deep interiors of the forests. It may, however, be found frequently breeding in the densest forest, in moist shady places far removed from an opening of any sort.
It places its nest most often in low thick bushes, or almost as often in among the moss growing on tree-trunks or rocks, and it seems to have a great affection for the great decaying trunks of fallen trees, which are covered all over with moss, orchids and other kinds of vegetation, tucking the nest away among them so that it is very difficult to find. Occasionally it is built actually on the ground, generally on some sloping bank, which, however wet, allows most of the rain to run off. It is, apparently, never built at any great height from the ground, whether placed on tree, rock or small bush. Most often it will be found within 18 inches to 3 feet from it, less often 4 or 5 feet and, sometimes, as I have already said, actually on the ground itself.
The nest is shaped like an oval ball and is always domed. One of the first taken by myself had the following measurements:— External height 5.4 inches ; diameter 3.9 inches ; cavity 3 x 2 inches ; entrance high up on one side about 1.8 x 2 inches. Other nests might be as much as half an inch less each way outside, but not many would be found to exceed the above. They are well and compactly put together and stand quite a lot of handling and pulling about without coming to pieces. The materials in most cases consist mainly of bamboo-leaves, dead leaves of trees and skeleton leaves, loose materials in themselves but well bound together with long roots and strands of green moss. Both roots and moss are thoroughly twisted in and out of the loose materials, whilst the moss is also used largely in coating the exterior of the nest. This varies, though, greatly in extent. I have seen nests which looked as if made entirely of moss and others in which the moss only showed through in scattered patches here and there. Wherever they are placed the nests are wedged in among the moss, orchids or twigs of the bush and the material is seldom, if ever, wound round the latter or built in with the former. The lining is in two parts : first a layer of rhizomorph, roots, or very fine fern-stems and then skeleton leaves, of which quite a thick pad is usually placed at the bottom of the cavity. Scraps of grass, bark and fibre of various kinds are often mixed in with the dead leaves but, whatever other materials are made use of, skeleton leaves always seem to preponderate.
Gammie and Mandelli both took the nests of this bird near Darjiling at about 5,000 feet and these are described as very similar to those found by myself.
The breeding season is a long one and I have found eggs from early April to late July. Most birds, however, are late breeders and more eggs are laid in June and early July than at any other time.
Both birds assist in incubation and, of the great number we trapped on the nests, the sexes were very fairly divided. Both birds also take part in the construction of the nest.
They are shy, retiring little birds, slipping quietly off the nests when disturbed and, after a flight of a few yards, diving into the bushes ; they return fairly quickly, however, to the nest if the disturber keeps quiet and still.
In the Eastern portion of its range the male bird seldom acquires the blue adult plumage and, even then, does so only partially, except in very rare cases. They breed constantly in the brown plumage.
The full complement of eggs is three or four, perhaps more often the latter, though I have found clutches of two more or less incubated. The eggs are in ground-colour a pale olive-green, sea-green or, rarely, pale olive-brown, but in most eggs the whole surface is so completely covered with innumerable tiny specks and freckles of light reddish-brown that they give one the impression of being unicoloured olive-brown eggs. In a few specimens the freckles may be less numerous at the smaller end, and I have one beautiful clutch of three marked only at the larger end, with coalescing freckles of rather bright reddish.
In shape the eggs are ordinary to rather broad ovals, often with the smaller end considerably compressed, though never very pointed. The texture is fine and clear and there is sometimes a slight gloss.
Sixty eggs average 19.5 x 14.6 mm. : maxima 22.4 x 15.2 and 22.3 x 15.6 mm. ; minima 18.5 x 14.2 and 19.0 x 14.0 mm.
489. Heteroxenicus nipalensis nipalensis
(489) Heteroxenicus nipalensis nipalensis (Hodgs.).