(773) Dicrurus leucophaeus hopwoodi Stuart Baker.
THE ASSAM GREY DRONGO.
Dicrurus leucophoeus hopwoodi, Fauna B. I., Birds, 2nd ed. vol. ii, p. 361.
The Assam Grey Drongo is found in Assam South of the Brahma¬pootra, Eastern Bengal, East of the Bay of that name, Manipur, Lushai Hills, Chittagong Hill Tracts and the Northern parts of the Chin and Kachin Hills and Northern Shan States. Birds breeding at Bhamo are certainly of this race but, farther South, they all appear to be nigrescens.
In its breeding habits this Drongo is quite typical of the species and of the genus but is probably more of a forest bird than most of the races of leucophoeus. Often during the breeding season it haunts forests of both Pine and evergreen, sometimes breeding well inside the interior of these, though generally selecting trees nearer the outskirts. It is, however, quite a familiar bird round villages and towns, and will nest even in gardens when these are well “wooded and supply suitable trees.
There are no records of the breeding of this race in Hume’s ‘Nests and Eggs,’ all the references there referring either to the Eastern or Western Himalayan forms.
In the Cachar Hills it was a common bird and in the Khasia Hills even more so. It bred in these hills from the level of the plains up to 6,000 feet and in the Naga Hills up to 7,000, but was undoubtedly more numerous between 3,500 and 5,000 feet than above and below these elevations.
In North Cachar, which is practically all forest or jungle of some kind, just interspersed here and there with small patches of grass¬land and other patches of cultivation, cut out of and surrounded by virgin forest, it certainly selected trees in or near these patches in which to breed, but many nests were placed inside the evergreen forest, though never very far in.
In the North-East of this district, where vast expanses of park¬like grass-land covered most of the country, these Drongos were rare or altogether absent. In the Khasia Hills, on the contrary, the birds were to be found equally abundant in both types of country. They were particularly numerous round the town of Shillong in the open spaces between the Pine forests.
In the Chin Hills, also, where Mackenzie and Hopwood obtained a fine series of their nests and eggs, they breed both in the quite open grass-lands, in the well-wooded country round villages and, sometimes, though more rarely, in the forests.
The nests are typical Drongos’ nests, that is to say, they are in shape shallow saucers, built, in two cases out of three, in horizontal forks of small branches on the outer parts of trees. Most nests are built at a great height and I have records up to 40 and 50 feet from the ground. On the other hand, in Margherita we often found them making their nests in quite small trees, Coltart and I both taking several nests at about 14 and 15 feet from the ground. In this district, also, we took several nests from quite stout vertical branches, well inside such trees as Jack and Mango ; these, we noticed, were generally rather bigger, deeper nests than those built high up in horizontal branches, which were so shallow that often it seemed, as they swayed in the wind, that the eggs must fall to the ground.
The materials used in making the nests were chiefly small pliant twigs, roots, both coarse and fine, grass-stems and cobwebs, the latter being employed both in binding the other articles together and also in fastening them to their supports. At odd times leaves, leaf-stems, thin weed-stems, lichen, scraps of bark and other materials are made use of, but only in small quantities. Occasionally I have seen bark or lichen used as an adornment on the outer walls, but never as it is by Minivets ; the nests reallyrequire little concealment, as they are built in such safe positions. When grass only is used, as is sometimes the case, this seems to be wound round and round and stuck together with cobwebs but, when roots and twigs are used, they are strongly intertwined, though, even then, the nests look fragile, more fragile than they really are, the free use of cobwebs greatly strengthening the structure.
Nests taken by myself and Coltart have varied in measurements as follows :—Outer diameter 4 to 4.3/4 inches, outer depth 1.1/2 to 2.1/2 ; egg-cavity 2.3/4 to 3.1/4 inches across and 3/4 to 1.1/4 in depth.
The walls are thin, though the rim round their tops is often fairly stout and strong, and the base is still thinner, the eggs being occasionally visible through them.
Both birds take a share in the construction of the nest, the male, for the most part, merely carrying the materials, which the hen places in position. I think the hen only incubates, but the cock bird keeps close to the nest and is most valiant—like all Drongos— in driving off enemies, either imaginary or real. The nest appar¬ently takes five to ten days to construct. One nest built in a small Mimosa in our garden at Shillong was completed in five days and the first egg laid on the sixth day. The birds worked very hard on this nest and rested for very few periods, except in the middle of the day. Another nest, built in some scrub, took at least ten days to build. When we first noticed the birds they had already placed the tie across the outer part of the fork which, later, forms the outer rim, and this may have taken them a day to put in order. From then on they worked by fits and starts, sometimes putting; in two or three feverish hours in a morning, after which they must have stopped altogether, as no further advance had been made in the work on our next visit. The eggs in this nest took thirteen, days to hatch.
In Assam, both in the Surrma Valley and in Lakhimpur, we found that most birds bred in May and June, though we found nests with fresh eggs from the 14th April to the 28th July. In the Chin Hills Mackenzie and Hopwood took nearly all their eggs in April, very few birds continuing to lay up to the middle of May.
The normal clutch of eggs is four, occasionally three only and, very rarely, five.
The eggs are like those of the Black Drongo group but, as a whole, are more richly coloured, more handsomely blotched rather than spotted, while I have never seen a pure white, unspotted egg.
The ground varies from a pure white, which is rare, through pale cream, pale salmon and pale yellowish-cream, to a rich deep salmon, salmon-buff or rosy pink. Most eggs are rather handsomely but not very profusely blotched with dark reddish-brown, sometimes with a purple tinge, sometimes with chocolate. Other eggs are spotted only with the same variety of colours, whilst a few are only finely speckled. Secondary marks of lavender, lilac, or pinkish-grey are to be found in all eggs, these being of the same size and character as the primary markings. Both primary and secondary blotches, spots, or specks are invariably more numerous at the larger end, where they often run into one another, occasionally forming quite well-defined zones.
One or two clutches in my series have a nearly white ground boldly blotched with chestnut-brown and greyish-pink, some of the former markings being almost black. Another clutch has a truly white ground with a ring at the larger end of each egg of small specks of light red, deep red and blackish, mixed with similar specks of lavender and pinkish-grey, the specks of both kinds being scanty elsewhere.
Two curious clutches have pale clear pink grounds marked all over with light brick-red, while in one clutch there are also pale purple marblings and a few blots of inky purple. A clutch of two has a yellow-salmon ground, with just a few deep purple-red blotches at the larger end, each blotch with a nimbus, as if the colour had run. Intermediate forms between all the above are common but I have never seen an unspotted really white egg.
In shape the eggs are most often broad ovals ; the texture is rather coarse but the surface is smooth, though glossless, except in rare instances.
Two hundred eggs average 24.6 x 18.5 mm. : maxima 27.5 x 19.3 and 25.3 x 20.0 mm. ; minima 21.9 x 17.3 mm.
773. Dicrurus leucophseus hopwoodi
(773) Dicrurus leucophaeus hopwoodi Stuart Baker.