The Geological History of the Ryukyu Islands
*This schematic is hand-drawn by Wanyu. The coastlines have no scientific basis. Please do not reproduce it, and do not use it in papers, reports, or other research publications.
Before about 12 million years ago (before the Middle Miocene)
At that time the Ryukyu Islands lay at the eastern edge of the Eurasian continent and were connected to it by land. In this era the land animals and plants of the islands were shared with the biota of the continent.
About 12 million to 2 million years ago (Late Miocene to Early Pleistocene)
Crustal movements began to separate the continent from the Central and Southern Ryukyus. In the Late Miocene (about 12 to 5 million years ago), the Tokara Strait and the Kerama Gap isolated the Central Ryukyus, trapping animals such as the Amami rabbit, spiny rats, and ground geckos there.
The Southern Ryukyus stayed connected to the continent until the Pliocene (about 5 to 2.6 million years ago). Species similar to continental ones then became distinct species or subspecies, which is why the Southern Ryukyus have many species resembling those of Taiwan and southern China. During the ice age 200,000 to 100,000 years ago, sea levels dropped, giving animals another opportunity to reach the Southern Ryukyus.
About 2 million to 20,000 years ago (Early to Late Pleistocene)
On the continent, land animals that shared ancestors with the Central Ryukyu species went extinct one after another. Today such animals survive only on the islands of the Central Ryukyus.
Rising and falling sea levels caused by climate change repeatedly separated and reconnected neighboring islands, fragmenting habitats and gradually driving species on each island to diverge. The three main islands of the Central Ryukyus are thought to have separated about 2 to 1 million years ago, and some species evolved further into distinct species or subspecies through geographic isolation. For example, the genus Tokudaia diverged into the Okinawa Tokudaia (T. muenninki), the Tokunoshima Tokudaia (T. tokunoshimensis), and the Amami Tokudaia (T. osimensis).
Last Glacial Maximum (about 20,000 years ago): Sea level dropped by about 120 m and the islands grew larger, but the sea still lay between them. The ancestors of the Iriomote cat are thought to have crossed from the continent to the Southern Ryukyus when sea levels fell and the distance between them narrowed.
About 20,000 years ago to the present (Last Glacial Maximum to today)
After the Last Glacial Maximum ended, sea level rose and the land area of the islands shrank. The present coral reefs began to form about 9,500 years ago.
July 2021
Amami-Oshima Island, Tokunoshima Island, the northern part of Okinawa Island, and Iriomote Island
Inscribed as a UNESCO World Natural Heritage site
Reason: conservation of biodiversity and habitat for threatened species
*Dates and content are based on the Ministry of the Environment Okinawa-Amami Natural Environment Office booklet “World Natural Heritage: Amami-Oshima Island, Tokunoshima Island, the Northern Part of Okinawa Island and Iriomote Island” (published November 2019, revised March 2024) and Atsuaki Kamiya, “The 300-Million-Year History of the Ryukyu Islands Told by Strata and Fossils” (Borderink). Researchers hold different views on the detailed coastlines of each period, so please treat them as a reference only.
Ancient Endemic Species of the Central Ryukyus
Endemic Genera of the Central Ryukyus
Endemic Species of the Central Ryukyus with Close Relatives on the Continent
The World Natural Heritage Islands
Yambaru, Okinawa Island
Yambaru (also spelled Yanbaru) is not a place name but a broad term for the forested environment of northern Okinawa. It refers in particular to the area north of the “Small Indian mongoose northward prevention fence” built between Shioya Bay and Taira Bay. Its core forest area was designated as Yambaru National Park on September 15, 2016.
The highest peak in the Yambaru region is Mt. Yonaha (503 m). The forest consists mainly of Okinawa Castanopsis (Castanopsis sieboldii) and Schima (Schima wallichii). Representative species include the Okinawa rail, the Okinawa woodpecker, and the Okinawa Ishikawa frog.
Tokunoshima
Tokunoshima lies between Okinawa Island and Amami Oshima. The central and northern parts have Castanopsis forests similar to those of Yambaru and Amami Oshima, but the south is characterized by cave formations created from limestone, giving it a distinctive geological landscape. Its biota resembles that of Amami Oshima, but species such as the Tokunoshima Goniurosaurus and the Tokunoshima Tokudaia can be seen only on Tokunoshima.
Amami Oshima
Amami Oshima’s highest peak is Mt. Yuwan (694 m). Its cloud and mist zone has high humidity, which suits epiphytic plants. Amami Oshima and northern Okinawa Island were once connected by land, so their biota are similar, with species such as the Amami Ishikawa frog and the Amami Tokudaia. Other representative species include the Amami rabbit, Lidth’s jay, and the Otton frog.
Iriomote Island
Iriomote Island is geologically composed mainly of sandstone, and much of its coast is covered by mangrove forests, making it the Japanese island with the most mangrove tree species. It has a high proportion of primary forest and many waterfalls. The island’s best-known species is the Iriomote cat, with only about 150 individuals remaining, making it extremely rare. The island is also home to species similar to those of southern China and Taiwan, such as the yellow-margined box turtle and the Sakishima habu.
Environmental Issues of World Natural Heritage
Invasive Species: Small Indian mongoose
Issues
- The small Indian mongoose was introduced in the 1910s to control Habu and rats
- Mongooses are omnivores and prey on fish, frogs, lizards, snakes, and even ground-dwelling birds. After they spread into the Yambaru region, they became a serious threat to the Okinawa rail
- When the Okinawa rail was discovered in 1981, its population was estimated at 1,700; by the 2000s it had fallen to about 700
Countermeasures
- In the 2000s, a “Mongoose Busters” team funded by the Ministry of the Environment and the Okinawa Prefectural Government was formed to capture mongooses in the Yambaru region
- Patrols and capture were carried out by hunters working with hunting dogs
- Using the terrain between Shioya Bay in Nago and Taiho Dam, a northward prevention fence was built to stop the mongoose from spreading north
Current Situation
- No mongooses have been found north of Prefectural Route 2
- North of the Shioya–Taiho Dam line, only about 20 to 30 mongooses are now captured each year
- Observation records of the Okinawa rail have spread to the mountains of Nago
- The range of rare frogs has also expanded
- On Amami Oshima, no mongooses have been found for many years, and the control effort was declared a success (eradication)
Related News
2025/1/6The Path to Eradicating Mongooses on Amami Oshima and the Future of Invasive SpeciesConservation OutcomesMongooseAmami Oshima
On September 3, 2024, Amami Oshima declared the eradication of the Small Indian mongoose, marking the first large-scale invasive species eradication globally. Introduced in 1979 to control the habu snake, the mongoose was eradicated after 45 years of effort. Key to success were the efforts of the Ministry of the Environment, Kagoshima Prefecture, and the Amami Mongoose Busters. The 2005 Invasive Species Act expanded budgets and established dedicated teams, marking a turning point. The eradication declaration followed six years of monitoring and high eradication probability calculations.
Source：Science Portal ↗
2024/9/15Mongooses introduced as predators of habu on Amami Oshima, but harm native species; 'Busters' eradicate them
An exhibition on Amami Oshima showcases the eradication history of the Small Indian mongoose, introduced in 1979 to control habu snakes. However, they harmed native species like the Amami rabbit. The Ministry of the Environment started control measures in 2000, and the 'Amami Mongoose Busters' team was formed in 2005, accelerating efforts. No mongooses have been captured since April 2018, leading to a declaration of eradication on September 3. The exhibition highlights the Busters' activities and aims to raise awareness of invasive species issues.
2024/8/31Amami Oshima to Declare Eradication of Mongooses... Introduced to Combat Habu, but Actually Attacked Amami Rabbits
The Ministry of the Environment is expected to declare the eradication of the Small Indian mongoose on Amami Oshima, where it was introduced in 1979 to control habu snakes. However, the mongoose attacked native species like the Amami rabbit. The eradication effort, which began in 1993 and intensified in 2000, has captured 32,600 mongooses, with the last capture in April 2018. Experts will evaluate the situation on September 3.
Source：読売新聞 ↗｜毎日新聞 ↗｜TBS NEWS DIG ↗｜沖縄タイムス社 ↗｜env.go.jp ↗｜朝日新聞 ↗｜日テレNEWS NNN ↗｜奄美新聞 ↗｜テレ朝NEWS ↗｜日本経済新聞 ↗｜産経ニュース ↗｜alterna.co.jp ↗｜琉球新報デジタル ↗｜南海日日新聞 ↗｜매일경제 ↗｜ピンズバNEWS ↗｜Yahoo!ニュース ↗
Invasive Species: Stray Cats and Dogs
Issues
- Owners of cats and dogs who do not take responsibility for them to the end abandon them in the natural environment
- In the 2000s, many cats and dogs lived in the mountains of Yambaru and killed Okinawa rails
Countermeasures
- The authorities set traps to remove stray cats and dogs
- Promoting spaying and neutering and adoption of pets, and requiring microchips
Current Situation
- According to a Ministry of the Environment pamphlet (revised in 2024), predation of endemic species by feral cats is serious in all regions except Iriomote Island, and capture is being strengthened
- In the three villages of Yambaru, 1,692 feral cats were captured over five years, of which 1,481 were returned to their owners or successfully adopted (reported in 2023)
- New cats and dogs may still be abandoned inside the national park, so continuous public education is needed
- Outside the national park, such as in city parks, there are still many cats and dogs
Related News
2026/6/29Tokunoshima's Ten-Year Management Plan Aims to Eliminate 'Ownerless Cats' to Protect Amami RabbitStray Cats and DogsTokunoshima
To protect Tokunoshima's ecosystem, a management plan targeting cats preying on the Amami rabbit has been developed by the Ministry of the Environment and local authorities. The ten-year plan aims to eliminate 'ownerless cats' by 2035. Originally, Tokunoshima had no carnivorous mammals, but cats were released outdoors to control habu snakes, leading to some becoming feral and threatening the Amami rabbit. The plan includes cat registration, indoor keeping, and banning outdoor feeding.
Source：読売新聞 ↗
2026/2/25Total Feral Cat Capture Reaches 772, Amami Rabbit Predation Continues, Conference Held in Amami OshimaStray Cats and DogsAmami Oshima
A conference on feral cat capture was held in Amami Oshima by the Ministry of the Environment. In 2025, capture operations covered about 91% of the island, capturing 45 cats by December, with a total of 772 cats captured. The status of rare wildlife is improving, and the need for new measures was acknowledged. The capture plan began in 2018 to protect ecosystems, and in 2025, operations were conducted in 19 areas. Feral cat numbers decreased, while Amami rabbit and Amami spiny rat numbers increased, but cat predation on Amami rabbits continues.
Source：南海日日新聞 ↗｜asahi.com ↗
2023/11/1Revised Feral Cat Management Plan to Expand Capture Range to Entire Amami Oshima by 2025, Ministry of the EnvironmentStray Cats and DogsAmami Oshima
The Ministry of the Environment has revised the feral cat management plan for Amami Oshima, expanding the capture range to the entire island by 2025. Since 2018, 491 feral cats have been captured. The plan aims to protect ecosystems by removing feral cats that threaten rare wildlife. Population estimates will be conducted in 2026-2027, and efforts to promote proper cat care will continue.
Source：南海日日新聞 ↗
Invasive Species: Other Invasive Species
Issues
- They arrived through pets, the transport of goods, food, and other routes
- Examples of invasive species:
- Feral goats: they have gone wild in the mountains of Iriomote Island, may feed on rare plants, and are difficult to capture
- Mikania micrantha (mile-a-minute weed): spreading widely on both Okinawa Island and Iriomote Island
- Taiwan habu: on the Motobu Peninsula it now outnumbers the native Habu
- Yaeyama firefly: it has become a domestic invasive species on Okinawa Island, and its larvae prey on a rare land snail, nearly driving it extinct in the wild
Countermeasures
- Some species are being removed
Current Situation
- Many invasive species are still not being comprehensively controlled, because of a lack of funding or because they have already spread too widely
Wanyu’s View
For invasive species such as the white-lipped tree frog, Leucaena (Leucaena leucocephala), and wedelia (Sphagneticola trilobata), the authorities take no active measures and let them grow unchecked.
Invasive Species News
2023/8/25Eradication of the Specific Invasive Species White-lipped Tree FrogInvasive SpeciesTokunoshima
On Tokunoshima, the eradication of the invasive White-lipped Tree Frog is underway, commissioned by the Ministry of the Environment. Since June, the operation has intensified, with university student volunteers joining from August 13. The NPO Tokunoshima Rainbow Association is leading the efforts, capturing 1,200 adult frogs and collecting 1,900 egg masses across 33 locations. Volunteers from across Japan are participating, with more expected to join.
Source：奄美新聞 ↗
2023/6/7Efforts to Prevent Impact on Native Species: White-lipped Tree Frog Eradication Begins in Tokunoshima
In June, Tokunoshima began a comprehensive survey and eradication of the invasive White-lipped Tree Frog. Known for its strong reproductive ability, this species is listed among Japan's top 100 invasive species. Previously unconfirmed in the Amami Islands except for Yoron Island, its presence in Tokunoshima was verified after local sightings were reported to the Ministry of the Environment. Volunteers and members of the local NPO are conducting eradication efforts to prevent island-wide spread during the critical breeding season from April to October.
Source：奄美群島南三島経済新聞 ↗
2023/5/19Invasion and Settlement of Designated Invasive Species 'White-lipped Tree Frog' in Tokunoshima Town
The White-lipped Tree Frog, a designated invasive species, has been confirmed to have invaded and settled in Tokunoshima Town, including Tokuwase, Morota, and Inokawa areas. Originating from Southeast Asia, this species poses a threat to native frogs by competing for resources. The Ministry of the Environment is calling for information to prevent ecological damage.
2023/8/12Concerns Over Possible Proliferation of Yaeyama Yellow Pond Turtle / 57 Captured in Two-Day SurveyInvasive SpeciesMiyakojima
The Yaeyama yellow pond turtle's population may be rapidly increasing, raising concerns about its impact on Miyakojima's rare species. A survey by the city's Environmental Conservation Division from June 26-28 in the Ono Forest captured 57 turtles, 1.5 to 2 times the expected number, indicating possible proliferation. This turtle, native to the Yaeyama Islands, is considered non-native to Miyakojima. Last year, 21 turtles were captured in a different location. This year, the survey moved to Ono Forest, capturing about 40 turtles on the first afternoon alone. A stomach content analysis is planned to assess its impact on rare species.
Source：宮古毎日新聞社ホームページ ↗
2023/7/18Aiming to Eradicate Japanese Weasels / Prefectural Environment DepartmentInvasive SpeciesMiyakojima
The Prefectural Environment Department is intensifying efforts to control Japanese weasels on Shimoji and Irabu Islands to protect rare species like the Miyako lizard. Introduced in the late 1960s to control rats, the weasels now threaten local wildlife. In 2021, 202 weasels and 747 black rats were captured. In 2022, trap numbers increased, capturing 428 weasels and 1,125 black rats. The prefecture seeks public cooperation by marking traps with signs.
Source：宮古毎日新聞社ホームページ ↗
Roadkill
Issues
- Amami rabbits, Ryukyu long-furred rats, Okinawa rails, and Iriomote cats all die in roadkill accidents
- Small animals such as Okinawa rail chicks and Okinawa crocodile newts fall into roadside gutters, cannot climb out, and die
- After the islands were inscribed as a World Natural Heritage site, the number of tourists and the volume of traffic increased
Countermeasures
- Grasp how accidents occur, collect sighting information, and publicize high-risk locations
- Install underpasses and fences that keep animals off the road
- Install signs that alert drivers
References
Click to expand: Okinawa rail roadkill accidents (2011–2026)
Number of traffic accidents (deaths and injuries not distinguished). 2026 data covers January to September. Source: Ufugi Nature Museum.
Click to expand: Ryukyu long-furred rat (Okinawa Island) roadkill accidents (2011–2026)
Number of traffic accidents (deaths and injuries not distinguished). 2026 data covers January to September. Source: Ufugi Nature Museum.
Click to expand: Ryukyu long-furred rat (Amami Oshima and Tokunoshima) roadkill accidents (2011–2025)
Number of traffic accidents (deaths and injuries not distinguished). 2026 data has not yet been published. Source: Ministry of the Environment, Okinawa-Amami Natural Environment Office.
Click to expand: Amami rabbit (Amami Oshima and Tokunoshima) roadkill accidents (2011–2026)
Number of traffic accidents (deaths and injuries not distinguished). 2026 data covers January to August. Source: Ministry of the Environment, Okinawa-Amami Natural Environment Office.
Click to expand: Iriomote cat (Iriomote Island) roadkill accidents (2011–2025)
Number of traffic accidents (deaths and injuries not distinguished). 2026 data is not yet available. Source: Iriomote Wildlife Conservation Center.
Related News
2026/9/22Successful Rescue Relay: Injured Okinawa Woodpecker Released After AccidentRoadkillYambaru
An Okinawa woodpecker injured in a traffic accident was released back into the wild in Kunigami. The male adult bird was found in April on a prefectural road in Kunigami's Yasuda area. After treatment and rehabilitation, it has successfully recovered and returned to nature.
Source：TBS NEWS DIG ↗｜NHKニュース ↗｜FNNプライムオンライン ↗｜琉球新報デジタル ↗｜QAB 琉球朝日放送 ↗｜Yahoo!ニュース ↗
2026/7/16Notice on the Start of Rehabilitation for Rescued Okinawa Woodpecker at Neo Park Okinawa (Second Case)
On April 20, 2026, an Okinawa woodpecker injured in a traffic accident in Kunigami was rescued and treated by the NPO Animal Hospital Okinawa. The bird is recovering well and began rehabilitation at Neo Park Okinawa on July 11. This is the second case following one in September 2026. Due to missing tail feathers, flight training will continue in a larger cage to prepare for eventual release back into the wild.
2025/9/30Amami Rabbit Traffic Accidents Near 100 Cases This Year: 'Drive Kindly to People and Animals' in Kagoshima, Amami OshimaRoadkillAmami Oshima
In Amami Oshima, traffic accidents involving the Amami rabbit have nearly reached 100 cases this year. Amami City officials are urging drivers to practice safe driving. The Amami rabbit is a rare species native to the island and is protected as a national natural monument.
Source：newsdig.tbs.co.jp ↗｜奄美新聞 ↗
2025/5/5Record High Roadkill in Tokunoshima: 42 Amami Rabbits in 2024, Ministry of the Environment
The Ministry of the Environment reported 242 Amami rabbit carcasses in 2024 on Amami Oshima and Tokunoshima, with roadkill being the leading cause. Tokunoshima recorded 42 cases, the highest ever, while Amami Oshima had 121 cases. The ministry aims to use this data for conservation efforts and urges the public to report any findings of injured or dead animals.
2024/2/15Do You Know the 'Crab Warning' Signs in Okinawa? The Reality of Animal Accidents on Roads and Their CountermeasuresRoadkillOkinawa Island (other)
In Senaga Island, Pacific land crabs cross roads between a hill and the sea, leading to roadkill incidents. Due to tourism development, crab numbers dropped from 150 in 2014 to 43 in 2017. Research by Jin'ya Yamazaki from Okinawa Prefectural Museum shows roadkill measures reduced incidents from 23 in 2016 to 7 in 2017. The 'Nature Positive' concept aims to restore nature and reverse biodiversity loss.
Source：merkmal-biz.jp ↗
Poaching
Issues
- The Central and Southern Ryukyus have many rare endemic species found nowhere else, and they have become targets for hobbyists who want to keep, cultivate, or collect them as specimens
- Many species are poached and sold abroad, or are kept in Japan and then abandoned, becoming domestic invasive species
- Rare species are becoming ever rarer
Countermeasures
- Amami Oshima and Tokunoshima: wardens, surveillance cameras, and forest road gates have been installed, some forest roads are closed to traffic, and joint patrols are carried out
- Northern Okinawa Island: surveillance cameras and joint patrols are in place, and some forest roads are closed at night
- Iriomote Island: information on the distribution of rare plants is being collected, a gate has been installed (Otomi Forest Road), and the nature conservation ordinance has been revised
- Illegally collecting wildlife is punishable by up to 5 years in prison or a fine of up to 5 million yen for an individual
Current Situation
- News of poaching has been constant in recent years
- The law protects only some rare species and has no power to restrict the collection of species that are not rare
Wanyu’s View
In recent years, poaching of land hermit crabs has been reported so often that it is hard to keep track of how many people have been caught. Even poaching thousands of land hermit crabs results only in a fine; the penalty is too light to be a deterrent.
Related News
2026/9/11Three Chinese Men Fined for Capturing land hermit crabss, Okinawa Summary CourtPoachingOkinawa Island (other)
Three Chinese men in their 20s were fined 400,000 yen each by the Okinawa Summary Court for illegally capturing and moving around 6,000 land hermit crabss, a national natural monument, in Okinawa from June to July. They were arrested in August for capturing 4,163 crabs in June and 2,207 in July without permission, intending to sell them. The Naha District Public Prosecutors Office filed a summary indictment in September.
Source：琉球新報デジタル ↗｜TBS NEWS DIG ↗｜Yahoo!ニュース ↗
2026/8/11[Overharvesting] Targeted Natural Monument: Three Chinese Nationals Repeatedly Poaching 'land hermit crabs', Re-arrested. Illegal Capture Totals 2 Cases, 6370 Crabs... How Can We Detect Poaching?
In Okinawa, three Chinese nationals have been re-arrested for allegedly repeatedly poaching the land hermit crabs, a designated natural monument. They are accused of illegally capturing a total of 6,370 crabs in two incidents. The rarity of the land hermit crabs makes it a target for poaching. This incident is part of a series of poaching activities, and the public is urged to be aware of poaching methods and signs.
2026/7/2468 Okinawa Black-breasted Leaf Turtles Return to Forest After Being Rescued from Chinese Poaching Group in OkinawaPoachingYambaru
In Kunigami, Okinawa, 68 Okinawa black-breasted leaf turtles rescued from a Chinese poaching group last October were returned to the forest on July 23. The turtles were microchipped by the Ministry of the Environment and the Okinawa Turtle Center for future tracking. The Ministry's official, Yoshihiro Takahashi, emphasized creating a community atmosphere that does not tolerate poaching. Despite legal protection, these turtles are in high demand as pets overseas due to their rarity.
Source：琉球新報デジタル ↗｜okinawatimes.co.jp ↗｜Yahoo!ニュース ↗
2025/10/25Four Chinese Nationals Suspected of Poaching in Yambaru Forest and Islands, Smuggling Endangered Turtles Disguised as Biscuits
Four Chinese nationals were arrested for poaching endangered species in Okinawa's Yambaru forest and islands, attempting to smuggle them to Hong Kong. They captured 107 Okinawa black-breasted leaf turtles, 2 Yamashina's ground geckos, and 1 Holst's frog. This is Japan's first case of turtle smuggling discovered through mail inspection. Okinawa Customs has charged three individuals.
Source：産経ニュース ↗
2025/10/24Suspected capture of endangered turtles, over 100 caught in Okinawa, Hong Kong woman and others arrested
On October 24, Okinawa police re-arrested four individuals, including a 32-year-old Hong Kong woman named Lin Su Yi, on suspicion of violating species preservation laws by capturing endangered Okinawa black-breasted leaf turtles. Between September 4 and October 3, they allegedly caught 107 turtles, 2 Yamashina's ground geckos, and 1 Holst's frog in Kunigami and Kumejima. Three of the suspects deny the charges, while one remains silent. Okinawa Customs has charged three of them with customs law violations, which have been accepted by the Naha District Public Prosecutors Office.
Source：Yahoo!ニュース ↗
2026/7/4"Even the small ones were uprooted..." 3869 land hermit crabss Poached, Four Vietnamese Fined 300,000-400,000 Yen in OkinawaPoachingOkinawa Island (other)
By July 3, four Vietnamese nationals were summarily indicted by the Naha District Prosecutor's Office for illegally capturing and transporting 3,869 land hermit crabss, a national natural monument, in Okinawa. The Naha Summary Court fined two men 400,000 yen each and two women 300,000 yen each. The incident was uncovered after a delivery company noticed something unusual and reported it to the police. The Okinawa Prefectural Board of Education urges cooperation to prevent poaching and advises the public to report suspicious activities.
Source：Yahoo!ニュース ↗
Overtourism
Issues
- Unregulated tourism and overuse trample the environment and make wildlife accustomed to humans
- Too many visitors damage the value of the World Natural Heritage site and also lower visitor satisfaction
Countermeasures
- Heritage area: impact is kept to a minimum and use is moderately controlled to offer a deeper nature experience. Some areas can be entered only with a licensed guide (for example, the Kinsakubaru area on Amami Oshima)
- Buffer zone: accepts a certain volume of nature-experience tourism
- Surrounding management area: can accept tourism by a larger number of people
Related News
2021/10/3Frequent Traffic Deaths of Wildcats on World Natural Heritage Iriomote IslandRoadkillOvertourismIriomote
The islands of Amami Oshima, Tokunoshima, northern Okinawa Island, and Iriomote have become Japan's fifth World Natural Heritage site due to their unique biodiversity. The Iriomote cat, along with the Amami rabbit and Okinawa rail, is a rare species facing extinction. Approximately 100 Iriomote cats remain, with vehicles being their biggest threat, causing 2 to 7 deaths annually. Despite measures by the Ministry of the Environment and local governments, four cats have died since April this year.
Source：産経ニュース ↗｜QAB 琉球朝日放送 ↗｜OTV 沖縄テレビ放送 ↗
2020/6/25Counter Installed at the Summit of Mt. Yuwan, Amami Oshima by the Ministry of the Environment｜World Natural HeritageOvertourismAmami Oshima
On June 23, the Ministry of the Environment installed a counter near the summit of Mt. Yuwan in Amami Oshima to monitor trail usage. With the area nominated for World Natural Heritage status, concerns about environmental impact from increased hikers have arisen. The ministry plans to trial access restrictions and usage rules by year-end. Mt. Yuwan hosts diverse flora and fauna, including the Amami rabbit, and sees about 4,000 hikers annually. Usage rules have been drafted after consultations with experts and conservation groups.
Source：南海日日新聞 ↗
2019/12/20Nighttime Use of Santaro Line Reaches a Maximum of 35 Vehicles｜World Natural HeritageOvertourismAmami Oshima
Due to the increase in nighttime wildlife tours, the Ministry of the Environment began monitoring the usage of Santaro Line in Amami City in July. As of the end of November, the highest number of vehicles recorded was 35 on August 27, with an average of 23.4 vehicles per day in late August. Local residents expressed concerns about the impact on wildlife and called for improved manners from guides and tourists. The area is home to the Amami rabbit and is part of a World Natural Heritage nomination area.
Source：南海日日新聞 ↗
Ecological Imbalance
Issues
- On Amami Oshima, control of invasive cats and dogs succeeded, and the Amami rabbit population has grown greatly
- However, its natural predator, the Habu, has declined sharply because of the bounty system
- The rabbits eat rare plants and crops, causing a decline in rare plants and agricultural damage
Wanyu’s View
I believe Japan should abolish the Habu bounty system and educate the public about the importance of the Habu in the ecosystem.
Related News
2025/6/1Crop Damage by Amami Rabbit Increasing Year by YearEcological DisruptionAmami Oshima
Associate Professor Naoko Kozai from Kagoshima University reported on the increasing crop damage caused by Amami rabbits in Amami Oshima. The damage, particularly to tankan trees, has been severe, with the bark of young trees being gnawed, leading to their death. The damage cost rose from 770,000 yen in 2017 to 9.83 million yen in 2023. Kozai is investigating why tankan is targeted, with no concrete data yet. The lecture also addressed mango cultivation issues, suggesting the introduction of Thai varieties that do not require low temperatures.
Source：奄美新聞 ↗
What We Can Do Here
- Take only photos. Do not take plants or animals home
- Do not release invasive species or pets
- Drive slowly, especially after rain
- Go with a certified eco-guide
- If you see suspicious people or vehicles, contact the Ministry of the Environment or the nearest police station
Not just seeing, but truly understanding