Geography of New Caledonia a refugium, in effect a biological "Noah's Ark", an island home to both unique living plants and animals and also to its own special fossil endowment. Birds such as the crested and almost flightless kagu (French, "cagou") "Rhynochetos jubatus", whose closest relative may be the distantly related sunbittern of South America, and plants such as "Amborella trichopoda", the only known member of the most basal living branch of flowering plants, make this island a treasure trove and a critical concern for biologists and conservationists. The island was home to horned fossil turtles ("Meiolania mackayi") and terrestrial fossil crocodiles ("Mekosuchus inexpectatus")
Kagu areas where soil levels of heavy metals were low laid more eggs and had higher numbers of fledglings, as well as having smaller home-ranges and higher body mass, than Kagu in areas where the soil was heavy-metal rich. It has therefor been suggested that Kagu conservation is likely to be more effective in areas where heavy-metal levels in the soil are low. The kagu had an important role in the traditional lives of the Kanak tribes of New Caledonia. Among the tribes found in the vicinity of Hienghène in the north of Grande Terre, its name was given to people,