(811) Tribura luteoventris.
The Brown Bush -Warbler.
Tribura luteoventris Hodgs., P. Z. S., 1845, p. 50 (Nepal); Blanf. & Oates, i, p. 364. Tribura mandellii. Blanf. & Oates, 5, p 365.
Vernacular names. Dao-tisha-tchik (Cachari).
Description. Whole upper plumage, wings and tail rufous-brown, the last a little darker and faintly cross-rayed: a dusky spot on lores; above this and running into a narrow supercilium pale buff; feathers of eyelids buff, forming a very distinct ring in some specimens; ear-coverts, sides of head and neck rufous, the first with faint white shaft-stripes ; chin, throat, middle of lower-breast and abdomen white; upper breast, flanks, vent and under tail-coverts rufous, the last more or less edged with white. In some specimens the chin, throat and extreme upper breast are marked with small spots of black (T. mandellii) and the colours of the upper parts vary greatly in the depth of the rufous tinge, some specimens being almost olive-brown ; these characteristics appear to be individual.
Colours of soft parts. Iris yellow-brown to bright hazel; bill above dark horny-brown or blackish, lower mandible and commissure fleshy-yellow or light horny, more yellow at the mouth ; legs flesh-colour, fleshy-yellow to " dark fleshy-brown (Cockburn).
Measurements. Wing 52 to 53 mm.; tail 55 to 66 mm.; tarsus 19 to 20 mm.; culmen 10 to 11 mm.
Distribution. Nepal, Sikkim, Bhutan and the hills of Assam both N. and S. of the Brahmaputra; Chin Hills, Annam.
Nidification. The Brown Bush-Warbler breeds in great numbers in the Khasia Hills above 4,500 feet, making a deep cup-shaped nest of grasses with an odd leaf or two in the base, and sometimes a weed-stem or tendril in the body of the nest. The lining, which is very thick, is of grass and grass-stems. Roughly the nests measure externally about 5 inches deep by less than 3 broad, the inner cup being about 2 1/2 inches deep by 2 inches or less in width. The number of eggs laid is nearly always four, very rarely five, and rather more often three only. In shape they are broad, blunt ovals; the ground-colour is white to pale pink or pale lilac and they are freely marked all over with freckles of various shades of reddish or pinkish brown. Most eggs are about the same in depth of colouring as the eggs of the Grasshopper-Warbler, others are as deep a brown-pink as the darkest eggs of Pallas's Grasshopper-Warbler, whilst others, again, are as pale as the palest eggs of the Spotted Bush-Warbler.
Two hundred eggs average 18.2 x 14.3 mm.: maxima 19.9.X 14.9 and 19.0 x15.2 mm.; minima 16.9 x 14.5and 18.0 x13.5 mm.
The nest is generally placed in a low bush or tangle of weeds, creepers and raspberry or blackberry vines and another favourite site is a Daphne bush. It is never placed actually on the ground,, but may be at any height from a few inches up to 3, or even 4 feet. The breeding-season commences in the end of April and lasts until late July.
Habits. This Bush-Warbler inhabits and breeds at lower elevations than any of its relations. In Summer it is found up to 9,000 or 10,000 feet but, far more often, between 5,000 and 7,000 feet, whilst in "Winter it descends to the foot-hills and even into the adjacent plains. It is one of the few birds which are found in great numbers in the pine-forests of the Khasia Hills, haunting in preference those which have an undergrowth of low Daphne bushes. It is not a particularly shy bird and does not resent being watched, though it is naturally a skulker and lover of thick cover, where it is difficult to see it. One notices a little russet bird flitting about inside the bushes from one twig to another, very restless and very energetic but very stealthy and quiet in all its ways. Every now and then a soft single " chik is uttered and this is all one hears, except in the breeding-season when it utters a complete little song from the top of a piece of grass or Daphne bush, much like that of the common Reed-Warbler, but much softer and lower. Like the rest of the genus and those closely allied to it, it lives entirely on the smallest insects and is very fond of ants and the smaller spiders. 1 once watched it in the Government House Garden in Shillong feeding on a blight which infested the rose-trees and so deeply engaged was it on its feast that it allowed me to watch it for some minutes from a distance of a few feet.