(617) Cochoa purpurea Hodgs.
THE PURPLE THRUSH.
Cochoa purpurea, Fauna B. I., Birds, 2nd ed. vol. ii, p. 184.
The Purple Thrush breeds from Kuman in the Himalayas to Eastern Assam and thence practically throughout all the higher hill-ranges of Burma as far South as Tenasserim. It breeds above 3,500 feet, certainly up to 6,000, and probably up to 8,000 feet, haunting evergreen forests with lofty trees and heavy wet under¬growth. Occasionally in the Khasia Hills it breeds in the Pine forests but, like many other species which breed in these woods, keeps entirely to the ravines running through them in which other trees and some undergrowth also grow.
The first nest ever taken of this Thrush was by Mr. Horne in Kuman, though at the time some doubt was felt as to the identi¬fication. Brooks, who forwarded the nest and two eggs contained in it to Hume, thus describes Horne’s note on the former:—“Nest very solid, of moss, built on a horizontal bough, 10 or 12 feet from the ground, in a small tree in a ravine near the top of Binsea. Interior nearly a true cup lined with white lichens, fine moss and principally black roots (very fine).”
I took several nests of this Thrush myself in the Khasia Hills and they agree fairly well with the above. The first nest I saw was built in a small tree growing in a deep and rocky ravine running through Pine forest but densely covered on its banks with evergreen trees and undergrowth. The nest itself, which was on a branch about 8 feet from the ground, was very like that of Zoothera but much less compact and well put together and more shallow in proportion to its size. Outwardly it measured roughly about 6.1/2 inches in diameter by about 2.1/2 deep, with an egg-cavity about 4 by 2 inches or rather less. The ends of the materials of which it was composed stuck out untidily in all directions to a distance of some inches. Outwardly it appeared to be all green moss but, when pulled to pieces, a certain number of dead leaves, a few roots and scraps of fibre were exposed. The lining was entirely of fine black roots mixed with white thread-like scraps of some fungus or lichen and one or two broader pieces. This use of lichen or white fungus material in the lining seems to be distinctive of the nests of the Purple and Green Thrushes. The nest was placed in a fork devoid of all leaves and conspicuous at some distance.
Other nests taken by myself or my collectors were very similar to the above and generally had white lichen in the lining. One or two were built in straggling bushes, but most in small trees from 6 to 20 feet from the ground.
They breed from early May to about the middle of July and are not double brooded. Nests found by myself were taken between the 5th May and the 13th July, in both instances with fresh eggs.
The full clutch is normally three eggs, but I have twice had clutches sent me, with birds and nests, of four.
The eggs are typically Turdine and can be matched with many eggs of T. rubrocanus, T. boulboul or T. unicolor but, as a series, they are very richly coloured and handsomely marked. The ground¬colour in the most common type is very pale to pale sea-green, handsomely blotched with bright reddish-brown and with secondary blotches of lavender and grey. In most eggs the markings are profuse everywhere, but more so at the larger end, where they sometimes form a cap. In the second type the ground is a pale reddish stone, the markings being similar to those in the first type but generally still more thickly laid on.
I have one pair of eggs a pale sea-green faintly flecked all over with pale reddish and lavender.
In shape the eggs are long oval, the texture smoother than in the eggs of Turdus, but glossless and not quite so strong in proportion to their size.
Fifty eggs average 31.3 x 21.6 mm. : maxima 35.1 x 21.5 and 31.2 x 23.0 mm. ; minima 29.3 x 20.5 and 31.2 x 20.3 mm.
Both sexes take part in incubation, as we have twice trapped the cock bird on the nest.
They are curiously quiet, shy birds, intolerant of observation, and slipping noiselessly off their nests when intruders are still at some distance.
617. Cochoa purpurea
(617) Cochoa purpurea Hodgs.