68 INDIAN PIGEONS AND DOVES 



Distribution. The Thick-billed Green Pigeon is found throughout the 

 Himalayas from Nepal in the west, through Sikhim, in all the hill-ranges 

 north and south of the Brahmapootra River, the better wooded parts of 

 eastern Bengal, throughout Burma, the Chin Hills, Shan States into the 

 extreme south of Tenasserim, Annam, Siam, and Cochin China into the 

 north of the Malay States. In the south of the Malay States, Borneo, 

 Sumatra, and the Phillipines it is replaced by the true curvirostra. 



The earliest notice of this form of Green Pigeon is the plate in 

 Latham's Synopsis of Birds, a figure which agrees quite well with the 

 Sumatran Thick-billed — or, as he calls it. Hook-billed — ^Pigeon, except that 

 it does not show the grey of the head. On this plate was founded the 

 description of Columha curvirostra in Gmelin (Systema Naturae, I p. 777) 

 in which again the grey of the head is not mentioned. There cannot, I 

 consider, be the slightest doubt that the present bird is the one depicted by 

 Latham and described by Gmelin, and the specific name for the Thick -billed 

 Pigeon must therefore be Treron curvirostra. Our Indian form, however, 

 is quite easily distinguished from the Sumatran bird, the latter being 

 separable at a glance by its generally darker hue both above and below. 

 In addition to this the grey of the crown is distinctly darker and more dull, 

 and often considerably restricted in area ; the upper-plumage is of a duller 

 darker green, and the under-parts, instead of being a comparatively bright 

 greenish-yellow, are a dull oUy yellow-green. 



In size the southern bird is also very much smaller, the wing running 

 from 4.90 in. ( = 124.4 mm.) to 5.12 ( = 130.0 mm.). 



Nidification. Wherever found the Thick-billed Pigeon is resident 

 and breeds, and in Cachar and the Khasia Hills I have taken great numbers 

 of their nests. They commence breeding very early and some few eggs 

 may be taken in the end of March, but April is the month in which most may 

 be taken, and they continue to lay throughout May and Jime, whilst in July 

 and August there is a fresh increase in the numbers breeding, so that it is 

 probable that most birds have two broods in the year. 



I do not think either nest or eggs can be distinguished from those of 

 Osmotreron pJmyrii, and like that bird the Thick-billed Pigeon is a very speedy 

 builder. A nest built in an orange-grove outside my house took only four 

 days to build, though for some few days previously the pair of birds were 

 constantly placing a few twigs in position, either in the same tree as that in 

 which they eventually built, or in one of the other orange-trees in the same 

 grove. 



Incubation, I believe, took fourteen days, but I caimot be sure as I was 

 afraid of disturbing the birds by too close inspection. They were not timid, 

 and did not niind my moving about in the orchard, although the nest with 

 the sitting bird on it was quite visible from one or two points of view. 



When nesting in the jungle they place their nests either in a sapling, 

 quite unconcealed, in a high bush or in a bamboo-clump, and very often two 

 or three nests are placed in close vicinity to one another. The male bird 

 takes at least an equal share in the duties of incubation, and also helps in 

 the building of the nest and the care of the young. 



The eggs are, as usual, two m number, pure white with a fine close grain, 

 very smooth, but not highly glossed. The average of 100 eggs is 1.10 in. by 

 .82 ( == 27.9 by 20.8. mm.), and the greatest length and breadth is 1.15 in. by 



Lr ^^-^ ^^^ ^^-^ °™-) respectively, and the least 1.07 in. and .79 

 ( = 27.1 and 20 mm.). 



