(823) Cisticola exilis tytleri Jerdon.
THE YELLOW-HEADED FANTAIL-WARBLER.
Cisticola exilis tytleri, Fauna B. I., Birds, 2nd ed. vol. ii, p. 420.
This very pretty little Warbler is found, wherever there are wide grass plains, from the Bhutan Dooars to Eastern Assam, Bengal, Manipur, Lushai, Chin and Kachin Hills to Yunnan from the foot-hills and plains up to about 2,500 feet. The highest elevation at which I have taken nests myself is on the great Umiam Plateau at about 3,500 to 4,000 feet, where the bird is quite common.
Whether it breeds in the actual plains at any distance from the hills is not certain, as no one has discovered its nest anywhere except in Assam, where I took many nests in North Cachar and the Khasia Hills, between 1,500 and 2,500 feet, and in Lakhimpur, where both Coltart and I obtained others in the foot-hills and adjoining plains. Stevens also found it breeding at Diju and other places close to the hills.
It keeps entirely to grass-lands, generally to the immense stretches of sun-grass so common in Assam, in which the grass may be anything from 3 to 5 feet high. Sometimes, however, it haunts hollows and ravines and the borders of rivers where elephant- grass and “ekra” grow to a height of about 10 feet.
In North Cachar I found it only in the gently rolling hills of the North, where the sun-grass in April and May was about 3 feet high and not very dense. In spite of this the nests were very difficult to locate. When breeding, the male bird has a lovely little call commencing with a soft “chr-r-r,” and then, after an interval, finishing with a fluty bell-like note which seems to have nothing to do with the previous note and to come quite from a different direction. I only found out that the two notes were uttered by the same bird when one, caught on the nest, performed for my benefit under the table where I was working. Even then I found it hard to believe that the two sounds were both uttered by it.
In looking for the nest one must locate the “chr-r-r” and dis¬regard the ventriloquial bell ; this takes one to where the cock is sitting and then occasionally one may locate the nest also when the hen bird takes flight.
The nest is of two, or really three, sorts. Sometimes it is a long purse-like affair of very fine grasses, lined with the feathery ends of the same. Such a nest may number one in twenty ; another type is egg-shaped and made of the same materials, and these may number about one in five. The common type of nest is a fragile- looking little watch-pocket fixed to the side of an upright leaf of some broad-leafed plant growing in among the grass. The nest is not built inside a leaf of which the two edges have been sewn together, but is so arranged that the leaf forms the back only. The materials, very fine grass-stems, are forced through holes made by the beak in various parts of the leaf and then knotted with tufts of the flowering grass-ends on the outside. Attached to the sides of the nest are more stems of grass, the other ends of which are fastened to the upper part of the leaf, so preventing the nest dropping when weighted with the young birds. A very favourite leaf for nesting purposes is that of the wild Ginger-plant, the roots of which are used by the hill tribes to flavour their food with. Several nests were brought to me by hill-men who had been collecting these roots.
The birds breed from April to July, according to the condition of the grass. Where this is burnt early in the year or is stunted and thin from poor soil, the nests are made in April and May but, where the grass is burnt late in March and April, there is no breeding until June and July. They do not, I think, have two broods, unless the first is destroyed early by accident. I have taken a few eggs in August which might be second broods, but these have generally been in places where the grass has not been burnt until very late.
The normal clutch of eggs is four but I have twice taken six and several times five. Three seems to be quite exceptional.
The ground-colour is a bright blue, paler than in the eggs of the common Wren-Warbler, but decidedly darker than those of the Tailor-Birds. The markings consist of deep red-brown blotches, spots and specks. As a rule the blotches are rather large and bold but at other times small and speckly, and these eggs, especially when the blue is very pale, could hardly be distinguished from those of Tailor-Birds. The secondary markings, if any, are of washed- out sepia or pale reddish. In all eggs the markings are few and in nearly all practically confined to the larger end. They very rarely form rings and never caps.
One hundred and twenty eggs average 14.8 x 11.4 mm. : maxima 16.1 x 11.6 and 16.0 x 12.0 mm. ; minima 13.1 x 11.0 and 15.5 x 10.9 mm.
In shape the eggs are broad, blunt ovals. The texture is very fine and smooth, many eggs having a fine gloss. They are stout little eggs, much less fragile than the same-sized eggs of Tailor-Birds.
Both sexes incubate but the males much less than the females ; both, also, assist in the building of the nest, though the male only brings the materials to the female. Incubation takes eleven days.
The male bird generally perches on a high piece of grass near the nest and is most unpleasantly alert and wideawake, warning the female long before one gets close enough to make sure of finding the nest. As soon as the warning note is uttered the female sneaks out of the nest and worms her way among the grass-stems for some yards before rising and flying, like a tiny Quail, in a bee-line for a hundred yards or so before tumbling headlong into the grass again.
823. Cistieola exilis tytleri
(823) Cisticola exilis tytleri Jerdon.