Amami-Ōshima, Tokunoshima, Okinawa settentrionale e Iriomote (Giappone)

The Galapagos of East Asia

Scattered between Kyushu and Taiwan in Japan's Ryukyu Archipelago, four island clusters — Amami-Ōshima, Tokunoshima, the northern part of Okinawa Island (Yambaru), and Iriomote — were inscribed as a UNESCO natural World Heritage Site in 2021. Though they span nearly 1,300 kilometres of ocean and were presented as a single serial nomination, they share a defining characteristic: each island was separated from continental Asia millions of years ago, allowing evolution to work in isolation and produce an astonishing concentration of endemic species found nowhere else on Earth. The site protects the largest subtropical rainforest in East Asia.

Geological History and Island Formation

The Ryukyu Islands were once part of the Asian continent but became progressively isolated through a combination of tectonic subsidence and sea-level rise beginning around 1.5 million years ago. The timing and degree of isolation differed between island groups, which is why species distributions within the site do not overlap completely: the Amami rabbit is confined to Amami-Ōshima and Tokunoshima; the Okinawa rail exists only in Yambaru; and the Iriomote cat lives solely on Iriomote Island. This pattern of island-specific endemism is the direct product of millions of years of separate evolutionary histories.

Flagship Species: Amami Rabbit and Iriomote Cat

The Amami rabbit (Pentalagus furnessi) is a living fossil — a nocturnal rabbit whose short legs, rounded ears, and dark fur resemble ancestral rabbit forms that preceded the modern Lepus genus. Only around 5,000 individuals survive on two islands. The Iriomote cat (Prionailurus bengalensis iriomotensis) is a subspecies of the leopard cat, of which fewer than 100 survive on Iriomote. It was unknown to science until 1967. Both species are Critically Endangered and their continued survival depends entirely on the protected status of their forest habitat.

Subtropical Rainforest Ecosystems

The forests of the inscribed areas are dominated by subtropical broad-leaved evergreen trees — particularly Castanopsis and Machilus species — interwoven with tree ferns, Pandanus, and dense undergrowth. Mangrove forests fringe the coasts of Amami-Ōshima and Iriomote, creating nursery habitat for reef fish and feeding grounds for the Iriomote cat and estuarine crocodile (in the case of Iriomote, habu pit vipers are the top predator in the absence of larger carnivores). The forest floor and canopy support hundreds of epiphytic orchid species and endemic ferns.

Bird Endemism: The Okinawa Rail and Beyond

The Yambaru forests of northern Okinawa are the sole habitat of the Okinawa rail (Gallirallus okinawae), a flightless bird rediscovered by science in 1981 after centuries of presumed extinction — making it one of the most dramatic ornithological rediscoveries of the 20th century. Approximately 1,500–2,000 individuals survive. The inscribed area collectively supports 36 endemic bird species and subspecies, including the Amami woodcock, the Ryukyu robin, and the Iriomote scops owl. Birdwatching in Yambaru is considered among the best experiences for endemic species in all of Japan.

Marine Fringe and Coral Biodiversity

Surrounding the islands are some of the most diverse coral reef systems in the northern Pacific. Iriomote's coasts support over 360 coral species, and the island's rivers discharge organic nutrients that feed reef food webs without the sediment overload typical of agricultural coastlines. Sea turtles — green, loggerhead, and hawksbill — nest on island beaches, and dugong still feed in the seagrass beds around Iriomote and Amami, representing the northernmost dugong population in the world. The marine buffer zones of the World Heritage property are essential to the ecological integrity of terrestrial ecosystems.

Invasive Species: The Mongoose Problem

The islands