(519) Enicurus schistaceus Hodgs.
THE SLATY-BACKED FORKTAIL.
Enicurus schistaceus, Fauna B. I., Birds, 2nd ed. vol. ii, p. 59.
The most Western points from which the Slaty-backed Forktail has been recorded are the Valleys of the Surjoo and Ramgunga in Kuman. Thence it extends throughout the Himalayas to Eastern Assam, practically the whole of the hill-country of Burma, Shan States, Yunnan, Siam and the Indo-Chinese countries to Southern China.
The elevations at which this Forktail breeds are decidedly lower than that of the preceding species. In Assam we found it not uncommon in Summer at 1,000 feet and even lower than this in the Dibrugarh district in the foot-hills around Margherita, where we took nests at about 700 feet. On the other hand it may be found breeding up to about 5,000 feet, though more often below than above 4,000. Like the last, it is a forest bird, but its nest is nearly always built on the banks of streams and not often by tiny springs and brooklets alongside forest-paths. In the Chin Hills, also, Wickham, who remarks that “it is common in all these hills,” says that it keeps more to the bigger streams than “the wee streams up the hills that E. guttatus delights in.”
Bingham found it breeding near Kaukarit at about 2,000 feet and Darling took two nests in the foot-hills at the bottom of Nwalabo Mountain in Tenasserim.
The sites selected by this Forktail for its nest are much the same as those chosen by the Spotted Forktails except that, as I have already said, they seem to be restricted to the banks of streams. They may be placed in among boulders, on ledges or in crevices of rocks, among the roots of trees or in holes in banks. A site often made use of by this bird, and very seldom by the Spotted Forktails, is a hole in a dead tree-stump overhanging a stream. Wickham Darling, Stevens and Coltart all obtained nests built in such holes, and I myself have also seen several. Some of these latter were built at a considerable height, six or seven feet in more than one instance, but generally in decayed hollows quite low down and, in every instance, overhanging the banks of a stream.
They are, I think, earlier breeders than the Spotted Forktails. Many birds lay in the first week of April and I have taken more nests and eggs in that month than in any other, though they breed freely all through May and June in the higher hills and I have seen eggs, though very rarely, in July and August, all probably second layings. Gammie took nests in Sikkim in May and July but Bingham found nests in Tenasserim on the 1st of March with eggs and on the 13th of that month another with unfledged young, whilst Darling took two nests in the same district of Burma on the 8th April.
In the Chin Hills Mackenzie and Hopwood found them breeding almost entirely in April.
In China (Howlik) Jones and Kershaw obtained eggs during May.
The nest is very similar to that of the Spotted Forktails but is smaller and generally deeper in proportion, the inner cup possibly averaging about 2 inches both in depth and diameter, some being smaller even than this. It is an equally beautiful and well-built nest of brilliant green moss but, sometimes, more dead leaves and roots are employed in the construction of the base. The lining is the same, skeleton leaves being invariably used for this purpose, neatly matted down all round the sides as well as at the bottom.
The eggs are three or four in number, generally four. In appear¬ance these are of two types : one, the least common of the two, is exactly like a washed-out poorly-marked specimen of E. m. guttatus, very often with a rather more distinct pinkish tinge ; the second type has the ground-colour a very pale bluish-white sparsely but boldly speckled or spotted with rather dark reddish-brown primary spots and often with secondary ones of inky purple and lavender. I have one very unusual clutch with a pinky white ground spotted in a similar manner with light reddish and with underlying and not very conspicuous marks of pinkish-grey.
In shape the eggs are generally rather broad ovals, though long ovals are not rare, and the texture is closer than in the eggs of the E. maculatus group, a few eggs possessing quite an appreciable gloss, especially those of the second type.
One hundred eggs average 21.4 x 16.3 mm. : maxima 24.0 x 17.0 and 22.2 x 17.2 mm. ; minima 20.0 x 16.0 and 21.2 x 15.2 mm.
Both parents take part in incubation and both assist in building the nest.
As with other Forktails, this species nearly always seems to have a very well-marked territory within which no outsiders of its own kind are permitted to feed, though it has no objection to Wagtails, Redstarts and other birds feeding and breeding within it.
519. Enicurus schistaceus
(519) Enicurus schistaceus Hodgs.