World Heritage Identification Number: 1574
World Heritage since: 2021
Category: Natural Heritage
WHE Type: Natural Landscapes & Geographic Features
Transboundary Heritage: No
Endangered Heritage: No
Country: 🇯🇵 Japan
Continent: Asia
UNESCO World Region: Asia and the Pacific
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Biodiverse Islands of the Ryukyu Arc: A UNESCO World Heritage Site
The Ryukyu Arc, a chain of islands situated in the southwest of Japan, is home to a unique and diverse ecosystem that spans across four islands: Amami-Oshima Island, Tokunoshima Island, the northern part of Okinawa Island, and Iriomote Island. This collection of islands, inscribed as a UNESCO World Heritage Site in 2021, encompasses 42,698 hectares of subtropical rainforests and boasts an exceptional biodiversity value.
More to come…UNESCO Description of the World Heritage Site
Encompassing 42,698 hectares of subtropical rainforests on four islands on a chain located in the southwest of Japan, the serial site forms an arc on the boundary of the East China Sea and Philippine Sea whose highest point, Mount Yuwandake on Amami-Oshima Island, rises 694 metres above sea level. Entirely uninhabited by humans, the site has high biodiversity value with a very high percentage of endemic species, many of them globally threatened. The site is home to endemic plants, mammals, birds, reptiles, amphibians, inland water fish and decapod crustaceans, including, for example, the endangered Amami Rabbit (Pentalagus furnessi) and the endangered Ryukyu Long-haired Rat (Diplothrix legata) that represent ancient lineages and have no living relatives anywhere in the world. Five mammal species, three bird species, and three amphibian species in the property have been identified globally as Evolutionarily Distinct and Globally Endangered (EDGE) species. There are also a number of different endemic species confined to each respective island that are not found elsewhere in the property.
UNESCO Justification of the World Heritage Site
Criterion (x): The property contains natural habitats of outstanding importance for in-situ conservation of the unique and diverse biodiversity of the central and southern part of the archipelago in which the property is located. The five component parts constituting the property are located in one of the 200 ecoregions considered most crucial to the conservation of global biodiversity. The subtropical rainforests of the property are the largest remaining in the region and harbour a very rich flora and fauna, boasting at least 1,819 vascular plants, 21 terrestrial mammals, 394 birds, 267 inland water fish, 36 terrestrial reptiles and 21 amphibians. These include approximately 57% of the terrestrial vertebrates of the biodiversity hotspot of Japan, including 44% of species endemic to Japan as well as 36% of Japan’s globally threatened vertebrates. Among species listed on IUCN Red List of Threatened Species are the Amami Rabbit, only found on Amami-Oshima and Tokunoshima Islands and the only species in its genus, with no close relatives anywhere in the world, and the flightless Okinawa Rail, endemic to the Northern part of Okinawa Island. Spiny rats form an endemic genus consisting of three species endemic to each of the respective three islands, and the Iriomote Cat, which only inhabits Iriomote Island. Speciation and endemism are high for many taxa. For example, 188 species of vascular plants and 1,607 insect species are endemic within the four islands of the property. Rates of endemism among terrestrial mammals (62%), terrestrial reptiles (64%), amphibians (86%), and inland water crabs (100%) are also high. Twenty species are identified as Evolutionarily Distinct and Globally Endangered (EDGE) species, including the Okinawa Spiny Rat, Ryukyu Black-Breasted Leaf Turtle, and Kuroiwa’s Ground Gecko.
Encyclopedia Record: Amami-Ōshima Island, Tokunoshima Island, northern part of Okinawa Island, and Iriomote Island
Amami-Ōshima Island, Tokunoshima Island, northern part of Okinawa Island, and Iriomote Island (奄美大島、徳之島、沖縄島北部及び西表島) is a serial UNESCO World Heritage Site consisting of five component parts on four Japanese islands in the Ryukyu Arc. The site was selected in terms of biodiversity for having a diverse ecosystem of plant and animal species that are unique to the region.Additional Site Details
Area: 42,698 hectares
Number of Components: 5
Coordinates: 28.2791666667 , 129.3783333333
IUCN World Heritage Outlook
The 2025 Conservation Outlook on Amami-Oshima Island, Tokunoshima Island, Northern part of Okinawa Island, and Iriomote Island reports the following assessment:
Source: International Union for Conservation of Nature (IUCN) · View assessment
World Heritage Research
Discover scientific research and academic studies that deepen our understanding of Amami-Oshima Island, Tokunoshima Island, Northern part of Okinawa Island, and Iriomote Island from its history and significance to its conservation, management, and contemporary challenges.
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A first case of Hepatozoon infection in a wild Amami rabbit (Pentalagus furnessi) in Tokunoshima Island, Japan
Researchers have documented the first confirmed Hepatozoon infection in an endangered Amami rabbit (Pentalagus furnessi) from Tokunoshima Island, Japan. The discovery, made through necropsy and histopathological examination, revealed meronts—asexual reproductive stages—in the rabbit's lung, heart, and skeletal muscle tissues, with no associated inflammatory response. Transmission electron microscopy confirmed these intracellular structures at various developmental stages. Molecular and phylogenetic analyses identified the protozoan as Hepatozoon sp., closely related to Hepatozoon felis. The presence of asexual stages suggests that Amami rabbits may serve as intermediate hosts rather than paratenic hosts in the parasite's life cycle. This finding underscores the need for further study into the ecology, transmission dynamics, and conservation implications of protozoan infections in endangered wildlife.
Saito, T., Noguchi, H., Tokiwa, T., Yoshimura, H., Suzuki, R., Torimoto, R., Shiraishi, T., Matsumoto, K., Haritani, M., & Yamamoto, M. (2026). A first case of Hepatozoon infection in a wild Amami rabbit (Pentalagus furnessi) in Tokunoshima Island, Japan. International Journal for Parasitology: Parasites and Wildlife, 29, 101209. https://doi.org/10.1016/j.ijppaw.2026.101209
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Foraging of Endangered and Endemic Plant Species by a Non-Native Sika Deer Found in the Northern Part of Okinawa-Jima Island, Japan: Evidence from Fecal DNA Metabarcoding Analysis
A non-native sika deer (Cervus nippon) was discovered in the northern part of Okinawa-Jima Island raising concerns about its potential impact on endangered and endemic plant species. Fecal DNA metabarcoding analysis of one fecal sample from the deer revealed 24 plant species, including two endemic to the Ryukyu Islands, with one listed as critically endangered (CR) by Japan's Environment Ministry. The study suggests that if sika deer establish a population in this region, they could pose significant threats to local biodiversity and ecosystems. Immediate measures are recommended to prevent further invasions and mitigate potential ecological damage.
Kobayashi, S., Asato, H., Nakata, K., Nagata, J., & Watari, Y. (2026). Foraging of Endangered and Endemic Plant Species by a Non-Native Sika Deer Found in the Northern Part of Okinawa-Jima Island, Japan: Evidence from Fecal DNA Metabarcoding Analysis. Mammal Study, 51(2), 199–204. https://doi.org/10.3106/ms2025-0049
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Case Report: Neurological and pulmonary angiostrongylosis in a Ryukyu long-furred rat (Diplothrix legata) on Amami-Oshima Island, Japan
A Ryukyu long-furred rat (Diplothrix legata) on Amami-Oshima Island, Japan, exhibited neurological and pulmonary symptoms of angiostrongylosis caused by Angiostrongylus cantonensis. The case highlights the potential for this endangered rodent to manifest both neurological and respiratory disease manifestations due to infection with the ac1 lineage of A. cantonensis, distinct from lineages found on nearby islands. Gross and histopathological examinations revealed nematodes in the brain, lungs, and heart, accompanied by severe inflammation, hemorrhage, edema, thrombosis, necrosis, and concurrent Aspergillus infection. This finding underscores the need for further epidemiological studies to clarify transmission dynamics involving invasive rodents, terrestrial gastropods, and potential paratenic hosts within the Amami Islands.
Shinya, S., Tokiwa, T., Sakashita, K., Yoshimura, H., Suzuki, R., Torimoto, R., Muraoka, Y., & Yamamoto, M. (2026). Case Report: Neurological and pulmonary angiostrongylosis in a Ryukyu long-furred rat (Diplothrix legata) on Amami-Oshima Island, Japan. Frontiers in Parasitology, 5. https://doi.org/10.3389/fpara.2026.1797945
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EDNA reveals extraordinary fish diversity in the Urauchi River, Iriomote Island, Japan, a UNESCO World Heritage Site
A groundbreaking study using environmental DNA (eDNA) metabarcoding has uncovered extraordinary fish diversity in the Urauchi River, Iriomote Island, Japan—a UNESCO World Heritage Site. The research identified 254 fish species across 10–11 sampling sites along an 18.8 km stretch, with species richness peaking in mangrove zones of the mid-to-lower estuary. Notably, eDNA detected 16 conservation-priority taxa listed on Japan's Red List and six IUCN Red List species, including critically endangered Anguilla japonica and Cheilinus undulatus. The study also revealed unexpected detections of deep-sea taxa, likely due to tidal transport or diel migrations. Using high-throughput sequencing and advanced biodiversity analyses, the research demonstrated that fish biodiversity in this system remains incompletely characterized, underscoring the importance of integrating eDNA with conventional surveys for comprehensive assessments. This first molecular baseline provides a practical early warning system for detecting ecological shifts and guiding targeted conservation efforts in this globally significant watershed.
Pananganan, B. G. S., Juliano, M. G., Isowa, Y., Artigas Ramirez, M. D., Motomura, H., & Kajita, T. (2026). eDNA reveals extraordinary fish diversity in the Urauchi River, Iriomote Island, Japan, a UNESCO World Heritage Site. PeerJ, 14, e21399. Portico. https://doi.org/10.7717/peerj.21399
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Predation on an Okinawa Tree Lizard by an Amami Thrush Endemic to Amami-Oshima Island
Researchers documented the first recorded instance of vertebrate predation by the Amami Thrush (Zoothera dauma major), a bird endemic to Amami-Oshima Island, which preyed on an Okinawa tree lizard (Diploderma polygonatum polygonatum). This observation, made at the Amami Nature Observation Forest in February 2025, provides critical insight into the feeding habits of this scarce-foraging species. The study highlights the significance of such records for understanding predator-prey dynamics and the ecological role of endemic birds in the UNESCO World Heritage Sites of the Ryukyu Archipelago.
Higo, Y., & Mizuta, T. (2026). 奄美大島の固有鳥類オオトラツグミによるオキナワキノボリトカゲの捕食. Journal of the Yamashina Institute for Ornithology, 58(1), 75–78. https://doi.org/10.3312/jyio.58.75
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A new species of Rimboda Heller (Coleoptera, Curculionidae, Conoderinae, Othippiini) reared from Distylium racemosum Siebold & Zucc. in the Ryukyu Islands, Japan
Researchers have identified a new species of weevil, Rimboda saekii, from the subtropical forests of Amami-Oshima Island, Tokunoshima Island, Northern part of Okinawa Island, and Iriomote Island in Japan. This discovery marks a significant northward expansion of the genus Rimboda's known geographic range, which was previously limited to Indonesia, Malaysia, and the Philippines. The species was reared from Distylium racemosum (Hamamelidaceae), providing new insights into its ecological associations. The study includes detailed habitus photographs, 3D models, and illustrations of male and female genitalia, along with a comprehensive checklist of all known Rimboda species worldwide.
FUJISAWA, Y., LEWIS, J. H., & ANZALDO, S. S. (2025). A new species of Rimboda Heller (Coleoptera, Curculionidae, Conoderinae, Othippiini) reared from Distylium racemosum Siebold & Zucc. in the Ryukyu Islands, Japan. Zootaxa, 5575(2), 339–345. https://doi.org/10.11646/zootaxa.5575.2.10
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Biological invasion by the cycad‐specific scale pest Aulacaspis yasumatsui ( Diaspididae ) into Cycas revoluta ( Cycadaceae ) populations on Amami‐Oshima and Okinawa ‐jima, Japan
A recent biological invasion by the cycad-specific scale pest Aulacaspis yasumatsui threatens wild populations of Cycas revoluta, Japan's only native cycad, on Amami-Oshima and Okinawa-jima islands. This invasive species, originally from southeastern Asia, causes significant mortality in non-adapted cycad populations, with potential ecological impacts still understudied. The research highlights the urgent need for monitoring the pest's spread and evaluating biological control methods using native predators. Given C. revoluta's known genetic diversity, establishing in situ and ex situ conservation colonies is recommended to preserve its genetic composition if populations decline.
Deloso, B. E., Gutiérrez‐Ortega, J. S., Chang, J.-T., Ito‐Inaba, Y., Lindström, A. J., Terry, L. I., Donaldson, J., Tang, W., Cave, R. D., Gómez‐Díaz, J. A., Handley, V. M., Griffith, M. P., & Marler, T. E. (2025). Biological invasion by the cycad‐specific scale pest Aulacaspis yasumatsui (
View Publication Record | Read PublicationDiaspididae ) into Cycas revoluta (Cycadaceae ) populations onAmami‐Oshima andOkinawa ‐jima,Japan . Plant Species Biology, 40(4), 280–291. Portico. https://doi.org/10.1111/1442-1984.12505
