The Megapodes differ from the other Gallinaceous Birds in having a large hind toe placed on the same level as the three front toes. They also differ in that they do not incubate their eggs but leave them to be hatched in a mound of earth or rubbish, the necessary heat being apparently developed by the decay of these substances.
The Megapodes occur chiefly in Australia and the islands of the Pacific Ocean, but one species extends to the Nicobar Islands and consequently must be included in my volume.
In the Nicobar Megapode the sexes are alike. The tail is short, rounded and composed of twelve feathers. There is no crest, and the crown of the head is frequently bare of feathers. The skin round the eye is naked. The claws of the foot are extremely long. The general aspect of the Nicobar Megapode is similar to that of a small domestic hen. The young birds are hatched feathered, and can fly almost at once.
The most remarkable fact about the Megapodes is the mode in which the eggs are incubated. Each pair of birds commences to build a mound by scraping together sand and rubbish. At intervals during the construction of the mound the hen lays an egg, which is covered up, and then another till as many as ten eggs are laid; the mound is then completed and the eggs left to be hatched. Some mounds are as much as five feet in height and thirty feet in circumference.
Mr. Hume thus describes the chicken : "The quite young bird, when rather less in size than a quail, is a uniform snuff-brown all over, everywhere densely feathered, even about the throat and neck, and with the feathers of the forehead and the top and back of the head much longer actually, and not merely relatively, than in the adult; no bare space in front of or round the eye, no tail developed, only a large bunch of fur-like feathers, but the wings large, strong and well formed; the bill very short."