(475) Tesia cyaniventer cyaniventer-
The Slaty-bellied Wren.
Testa cyaniventer Hodgson, J. A. S. B., vi, p. 101 (1837) (Nepal). Tesia cyaniventris. Blanf. & Oates, i, p. 192.
Vernacular names. Tisi (Nepal); Samtit-tammong (Lepcha); Ting-linrui bermai-ga (Kacha Naga).
Description. The forehead, chin and nape, glistening golden olive-brown, the yellow more pronounced at the sides of the crown where it forms a fairly definite supercilium; the rest of the upper plumage and the visible portions of the closed wings and tail olive-green; lores and a broad stripe from the lores to the nape black; sides of the head and whole lower plumage slaty-blue.
Colours of soft parts. Iris brown, sometimes, according to Cockburn, vermilion; bill above and on the tip of the lower mandible dark brown, the remainder pale horny, often yellowish or tinged with orange; legs and feet pale fleshy to pale dull fleshy-brown.
Measurements. Length about 100 mm.; wing about 44 to 47 mm.; tail about 20 mm.; tarsus 24 mm.; culmen 11 to 12 mm.
The adult female is similar to the male and does not differ as described by Oates.
The young bird has the whole upper plumage rather rufescent green and the lower parts dull, dark olive-green. The black line through the eye is acquired during the summer with the completion of the first plumage, but the full brightness of the adult plumage not until the following moult.
Distribution. Garhwal, Nepal, Sikkim, the whole of Assam North and South of the Brahmaputra, Chin, Kachin Hills and possibly Annam. McClelland's olivea, a name given to Assam birds, cannot stand, as the Assam birds differ in no way from the Nepal and Sikkim birds and I have seen specimens from the Kachin Hills every bit as bright above and as dark below as any specimen from those countries. They vary very greatly individually and large series are necessary for comparison.
Nidification. The Slaty-bellied Wren breeds in April, May and June South of the Brahmaputra and in June and July North of it, at all heights between 3,000 and 10,000 feet. The nest is a beautiful ball of bright green moss lined with moss roots and measuring some 5 inches in diameter, or, according to Hodgson, more oval in shape, measuring about 7 x 5 inches. It may be placed either in a tangle of creepers or in dense, long moss against a tree or stump, or may be built in amongst the numerous branches of a thick, low bush, whilst, very rarely, it may be placed on a steep bank or against a rock or heap of boulders.
The eggs number three or four, very rarely five and vary considerably in appearance. The ground-colour is a very pale pink, often with a yellowish-salmon tint; the markings consist of reddish-pink specks and spots, sometimes so fine and so numerous as to make the eggs look an almost uniform terra-cotta, at other times sparser and much bolder, showing up well against the ground-colour and more numerous at the larger end than elsewhere. In shape they are normally rather long but blunt ovals. Fifty eggs average 17.4 x 12.9 mm. and the extremes are : maxima, 19.1 X 13'.1 and 17.9 x 13.6 mm.; minima, 16.8 X 13.2 and 18.0 x 12.0 mm.
Habits. This Wren is found over a greater range of altitude than any of the others with the exception of the next bird. It is certainly found up to at least 10,000 feet in Sikkim in summer, whilst, on the other hand, Stevens found it right down amongst the foothills and broken ground on the North bank of the Brahmaputra, but it must be remembered that in temperature the plains of North and North-East Assam are equivdent to an altitude of at least 2,000 feet South of the river and in Burma. It is a purely forest bird, preferring forests which have an ample undergrowth in which it can skulk about without showing itself. It is very loth to take flight and if one can mark it into a dense isolated busk it can easily be caught with a butterfly net. It much affects the vicinity of tiny water-courses through boulders and dense evergreen forest, and its high, shrill note may be heard mornings and evenings above the ripple of the water. It is exclusively insectivorous.