(164) Trochalopteron squamatum (Gould).
THE BLUE-WINGED LAUGHING-THRUSH.
Trochalopterum, squamatum, Fauna B. I., Birds, 2nd ed. vol. i, p. 174.
The Blue-winged Laughing-Thrush extends from Nepal to the extreme East of Assam, both North and South of the Brahmapootra, to the Northern Arrakan Yomas, the Chin and Kachin Hills and the North and South Shan States, whilst Forrest also obtained it on the Salwin-Shweli Divide in Yunnan.
Gammie many years ago found this bird breeding in Sikkim at Mangphoo, 3,500 and 4,500 feet, on the 18th May and the 30th April, whilst Hodgson records their breeding in Nepal from 2,000 to 6,000 feet. Osmaston, however, took their nests round about Darjiling at 6,500 to 7,000 feet.
In the Hills South of the Brahmapootra I found very many nests, nearly always between 3,000 and 4,000 feet, and above this up to 5,000 feet more sparingly. On one occasion only I took a nest above this height, nearly 6,000 feet, near Hungrum. My nests were nearly all found in quite low bushes between 2 and 4 feet from the ground ; one or two were built higher up in tall bushes and one on a sapling about 7 feet up. A very favourite site was a mass of Blackberry or Raspberry vines, sometimes growing in a tangle by themselves, sometimes clambering over and mixed up with some low bush. Always they were built in wet humid forest, generally in very thick jungle but sometimes in fairly open woods. They seemed to prefer, as so many birds do, the vicinity of streams, especially where these ran through well-wooded, damp forest with numbers of baby streamlets running into the bigger ones at the bottom of the valleys. The nest is a deep, compact, well-made cup measuring some 6 to 7.1/2 inches in diameter and from 3.1/2 to 4.1/2 inches in depth externally ; the egg-cavity measures roughly about 4 by 2.1/2 inches. It is constructed of leaves, fine twigs, grass and roots, with, perhaps, a few scraps of moss added to the outside ; the whole of this is quite tightly bound round with a few tendrils, long roots and, less often, with one or two weed-stems. Inside this there are nearly always some bamboo-leaves, the birds sometimes bringing these from quite a distance, while the true lining consists of roots or a fine brown fibre, probably the rhizomorph of a fungus.
Gammie describes one nest as “composed of dry bamboo leaves, held together by stems of delicate creepers and lined with a few black fibres.” I have seen no nests as primitive as this and the next nest he found seems from his description to have been very similar to those seen by myself.
May is the normal breeding month for this species. Hodgson says May and June, but in the lower hills we found very few in the latter month and both Gammie and I found fresh eggs on the 30th April. Osmaston, on the other hand, took one nest near Darjiling, 6,700 feet, as late as the 7th July.
The eggs number two to four, four very seldom, two only very often. In colour they are a beautiful, rather deep and very slightly greeny-blue, quite spotless and with a fine satiny surface, unlike that of most Laughing-Thrushes. They have no real gloss, though when fresh they have a very lovely sheen. The texture is similar to that in the eggs of the Barbets, though those, of course, are white. In shape they vary from rather broad to rather long ovals.
Fifty eggs taken by myself average 29.4 x 20.7 mm. : maxima 33.2 x 22.1 and 29.9 x 22.7 mm. ; minima 26.8 x 19.4 mm.
Osmaston’s eggs, taken at high levels in Sikkim, differ distinctly from the Assam eggs in being much paler and, on an average, decidedly bigger, his nine eggs averaging 29.9 x 22.2 mm. and running up to 33.6 x 24.2 mm.
These nine eggs are not included in the 50 eggs referred to as measured by myself.
Both birds take a share in incubation and both, also, take a part in construction of the nest, though it may be that the share of the cock is confined to the bringing of materials.
164. Trochalopteron squamatum
(164) Trochalopteron squamatum (Gould).