) in 1967. The Tongan megapode is the only remaining species of megapode in Tonga out of the four or five species that were present on the islands in prehuman times (as shown through the
fossil record), and indeed the only species of megapode that survives in
Polynesia. Similar extinctions occurred in
Fiji and
New Caledonia, which apparently had three species in prehistory. The species itself once had a more widespread distribution, occurring across most of Tonga,
Samoa, and
Niue. The cause of all these extinctions and declines was the arrival of humans on the islands, and the associated predation on adults and particularly eggs, as well as predation by
introduced species. On Niuafo'ou the small human population and remoteness of its habitat probably saved the species. The only
megapode to survive human arrival in Western Polynesia, "the megapode nesting grounds were carefully controlled by the ruling chief, thus assuring the continued survival of this population." Its natural
habitat is tropical moist lowland
forests. On
Niuafo'ou it is most common on the central caldera. The Tongan megapode, like all megapodes, does not
incubate its eggs by sitting on them; instead the species buries them in warm volcanic sands and soil and allows them to develop. On islands in former parts of its range without volcanoes it presumably created mounds of rotting vegetation and laid the eggs there. The young birds are capable of flying immediately after hatching. ==Status and conservation==