Green pigeons appear to live exclusively on fruit. They go about in small flocks, seeking out trees of which the fruit is ripe; when they hit upon such a tree they behave as if they were schoolboys let loose in a tuck shop!
The Hindustani name for the green pigeon is _Harrial_. The natives, or at any rate some of them, assert that the bird never descends to the ground, because when its foot touches the earth the bird loses a pound in weight, in other words, shrivels up into nothingness! If asked how it drinks, they will reply that it settles on a reed which bends with its weight, so that it is able to partake of the water beneath without touching the earth. In the absence of a conveniently situated reed, the green pigeon overcomes the difficulty by carrying a twig in its feet. It would be interesting to discover the origin of this story, which is on a par with that which asserts that the red-wattled lapwing (_Sarcogrammus indicus_) sleeps on its back with its legs in the air, in order to be ready to catch the sky on its feet if ever this should fall! As a matter of fact green pigeons are very arboreal in their habits. I do not remember ever having seen one of them on the ground.
The note of the green pigeons is not a coo, but a pleasant whistle. The birds are sometimes caged on account of their song. But they are uninteresting pets. In captivity they soon lose their beauty, because they are so gluttonous as to smear the head and neck with whatever fruit be given them to eat.
Green pigeons are said to be far less obtrusive in their courtship than the majority of their kind. The male does not puff himself out after the manner of other cock pigeons, but is content to bow before his lady love and in this attitude move his expanded tail up and down.
There are few birds that assimilate so closely to their surroundings as green pigeons. Fifty of them may be perched in a pipal tree, and a man on the look-out for them may fail to detect a single individual until one of the birds moves. They are thus excellent examples of protectively coloured birds. Their green livery undoubtedly affords them a certain amount of protection, and so may perhaps be considered a product of natural selection. Be this as it may, a consideration of the details of the colouring of their plumage shows that many of these, as, for example, the lilac on the wing, are quite unnecessary for the concealment of the bird. The eastern and the southern species which occur together in certain places and the hybrids produced by the interbreeding of these are all equally difficult to distinguish from the surrounding leaves, notwithstanding the fact that their plumage differs in details, e.g. the breast and the abdomen are greenish yellow in the southern and ashy-grey in the eastern form, while there is green in the forehead and tail of the latter, but not of the former. Thus we have two species of green pigeon, of which at least one has not originated by natural selection. Facts such as these, however, do not prevent Dr. Wallace, Sir E. Ray Lankester, and Professor Poulton continually proclaiming from the housetops that every existing species owes its origin to natural selection and nothing but natural selection!