Green birds are comparatively few in number, but nearly all of those that do exist are very beautiful objects. Green is a colour which is rarely found alone in birds. The fowls of the air of which the plumage is mainly green almost invariably display patches of other colour. In the familiar green parrots red, pink, blue, and black occur; the green coppersmith flaunts the most gaudy hues of red, crimson, and yellow; the emerald merops adorns itself with gold and turquoise ornaments; while green pigeons are birds which display the whole spectrum of colours, each in a subdued form. In the common Indian species the forehead is greenish yellow; the nape and sides of the head French grey; the chin and neck are old gold shading off into olive; the body is greenish olive; the shoulder is washed with lilac. The primary wing feathers are dark grey, while the secondaries are similarly coloured, but have pale yellow tips. The tail is slate-coloured, becoming greenish yellow at the base. The feathers under the tail are a dark claret colour with creamy bars. The lower parts are slate-coloured tinged with green, save for the feathers of the thigh, which are canary yellow. The legs are orange yellow. The eye is blue, with an outer ring of carmine. Yet, notwithstanding all this show of colour, there is nothing gaudy about the green pigeon. Every tint is most delicately laid on, and each hue blends into the surrounding ones in a truly exquisite fashion, so that it is no exaggeration to call the green pigeon a vision of perfect loveliness.

In the unlikely event of any one taking the trouble to compare the above description with those given in the fauna of British India for Crocopus phoenicopterus (the Bengal green pigeon) and C. chlorogaster (the Southern green pigeon), that person will observe that it does not tally exactly with either of them. Nevertheless, my description is taken from a specimen shot by me in the Basti district of the United Provinces. The fact of the matter is that in places where the Bengal form meets the southern species the two interbreed, as, I believe, do all, or nearly all, allied species at the point of junction. And, in such cases, the hybrid birds appear to be perfectly fertile and to thrive equally with the parent species; neither of which would be the case were facts in accordance with the Wallaceian theory. But, as we shall see later, green pigeons seem to lay themselves out to destroy the biological orthodoxy of to-day.

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!

There are several genera of green pigeons, and all of them are characterised by short legs and broad toes. These are adaptations to the arboreal habit, in the formation of which natural selection has, in all probability, played an important part. The habits of all the genera are identical. They, one and all, build the rough-and-ready shakedowns which do duty for nests amongst the ColumbidÆ. All lay the inevitable two white eggs. Yet the sexes of the genus Crocopus are alike in external appearance, while those of the genera Osmosteros, Sphenocercus, and Treron exhibit considerable dimorphism. Again in the genus Butreron the sexual differences displayed are inconsiderable. These facts, of themselves, are quite sufficient to disprove the theory that sexual dimorphism in birds is due to the hen’s greater need of protection. Cock green pigeons assimilate so well to their leafy environment that there cannot possibly be any necessity for their wives to be differently dressed. Further, it is worthy of note that the most flourishing of the genera of green pigeons is that in which the sexes dress alike.