While the species survived for hundreds of years of Polynesian settlement, even despite the establishment of introduced predators, at some point in the last millennium Mangaia suffered an ecosystem collapse with far-reaching consequences, the extinction of "P." rua among them.
It alludes to the name of the type locality, Te Rua Rere ("The Flying/Jumping/Throwing Cave"), als well to the fact that the prehistoric deposits of Mangaia were metaphorical "graveyards" of extinct fauna, with this rail being one of the most numerous.
Given that the number of rail bones in prehistoric deposits declines slowly for several centuries, and then suddenly collapses to zero, the Mangaia crake was not dependent on the central upland forest habitat, and may well have utilized all parts of the island in its pre-human state.
In the initial phase of the settlement, the central hill was logged and converted to agricultural fields; the rails still managed to hold their own against the pressure by the habitat destruction and the depredations of the rats, dogs and pigs, and persisted in considerable numbers.
Other than the rat, the first settlers also introduced chickens, dogs and pigs, but the latter two were at one point exterminated, probably deliberately to eliminate them as competitors for human food: at some time into the second millennium CE – probably around the end of the 14th century – numerous indications of an ecological catastrophe occur on Mangaia.
Mangaia crakes, seabirds and their eggs, and the Polynesian ground dove, which had until then been eaten at a rate that was nearly sustainable, suddenly became dominant food items and their populations rapidly plummeted, while less-desirable seafood such as sea urchins replaced crustaceans and large fish in the Mangaians' diet.
Local oral history attests to a period of frequent ritualized warfare, the previous hereditary chiefdoms being replaced by a highly militarized meritocratic warlordism which constantly reassigned the remaining fertile puna swampland between the makatea and the hill to the victorious parties of the battles, while the losers were displaced to the makatea where agriculture was restricted to the occasional soil-filled cavern, until they managed to win a battle and take over a patch of puna again.
Similar events are attested for the northeastern and northwestern ends of Mangaia as the battles named "First and Second Oven of Men" due to the victorious party burning the vanquished en masse.
The Polynesian deity Rongo, usually a god of peace and abundant harvests, was transformed into a patron of warfare and irrigated taro cultivation, and a cult involving mandatory human sacrifice at each accession of a new supreme warlord became the focal point of Mangaian religion.
Due to the good stratigraphic data and formerly large population providing numerous well-dateable specimens, the Mangaia crake's extinction can thus be quite precisely dated to the first half of the 15th century CE, most likely around 1425.