(761) Graucalus macei siamensis Stuart Baker.
THE BURMESE LARGE CUCKOO-SHRIKE.
Graucalus macei siamensis, Fauna B. I., Birds, 2nd ed. vol. ii, p. 345.
This is probably the best known of the large Cuckoo-Shrikes and it also has the widest range. On its extreme Western limits it occurs in Assam, South of the Brahmapootra, in the districts of Eastern Bengal East of the Bay of Bengal ; practically the whole of Burma from the Chin, Kachin and Bhamo Hills to Tenasserim ; Shan States and Yunnan ; Siam and the Indo-Chinese countries. It is found alike in the plains near the hills and in the hills them¬selves up to 4,000 feet. In Assam we seldom saw them above 3,000 feet and they were also resident in the plains, but were most common between 1,500 and 3,000 feet in forest which was not too dense or humid. They also build in big trees standing singly or in clumps on the edges of cultivation or on those by roadsides running through well-wooded country. I have personally never seen them breeding close to human habitations, nor have I any record of their doing so except in the Andamans, where these Shrikes are exceptionally common and sometimes make their nests on the Rain-trees in the avenues on the roads about the settlement of Port Blair. Here Osmaston took a wonderful series of their nests and eggs between the 5th of March and the 28th May, nearly all on Rain-trees (Pithecolobus saman), at heights of about 25 to 30 feet from the ground.
Except that in some cases the nests taken by myself in Assam were much higher up in trees—in one case, I think, about 60 feet, and in other instances still lower, down to 15 feet—the nests taken by Osmaston were in all respects like those taken by myself.
The most usual height was about 30 feet from the ground, but the nests were always placed in most impossible positions, generally in small outer forks of thin branches on the outside of the tree. It was easy for small boys to get within a few feet of the nest, yet quite impossible, as a rule, for them to get near enough to make a grab at the nest and its contents. Sometimes, however, they could get above it or else in such a position that they could gently shake the branch and drop the eggs, one by one, into a butterfly-net held just below the nest by another small boy. The eggs once in safety, the branch containing the nest could be cut off and brought down.
Two nests out of every three were placed in small horizontal branches. The third might be wedged into a vertical branch or built on the upper surface of a larger branch or upon two or more smaller branches growing close together. The nests were very small for so large a bird and were generally almost invisible from below until the bird showed exactly where they were. They probably average something between 4.1/2 and 5 inches externally by 2 or less in depth, the egg-cavity being about 4 inches by 1. The inside is very shallow, the base gradually sloping up to the lip, so that with care it is not difficult to shake the eggs out or to tip the nest so that they roll out without breaking.
The materials of which they are composed are mainly fine twigs, coarse roots and grass-stems, well interlaced without being tightly drawn, often made stronger by a few thin brown weed-stems or long grass-stalks being bound round about them. The whole is then well matted with cobwebs, inside and outside, while inside most nests will be found many tiny whole leaves or bits of larger leaves bound in with the spiders’ webs. Outside I have only seen lichen used when the surrounding branches are also covered with it, but often they are decorated with bits of leaves, small scraps of bark and spiders’ egg-bags, which are plastered on with cobwebs, the latter being wound, with some of the materials, round the supporting branches.
The nests look fragile and loosely put together but, as a matter of fact, are rather unusually strong, standing a good deal of rough usage on account of the large amount of cobweb employed.
Over the greater part of its breeding area two seems to be the usual complement of eggs laid, but Anderson and Osmaston both found one egg being incubated, and I once took a three in North Cachar.
The breeding season in Burma, so far as we know, and certainly in the Andamans, is March and April, a few birds breeding in May. In the Chin Hills Mackenzie took fresh eggs in April and early May while, in Assam, I found eggs in March, April and May.
The eggs resemble those of the other races and are very boldly marked handsome eggs. I have one pair in which the ground-colour is definitely brown rather than buff, and another in which it is a clear yellow-stone colour. As a series the eggs are, perhaps, a little longer on the average than those of the typical form.
Twenty-four eggs average 32.1 x 23.5 mm. : maxima 36.2 x 22.0 mm. and 32.0 x 24.0 mm. ; minima 30.0 x 22.2 and 30.3 x 21.3 mm.
Both sexes take part in incubation and both help in building the nest.
761. Grauealus macei siamensis
(761) Graucalus macei siamensis Stuart Baker.