Amami-Oshima Island, Tokunoshima Island, Northern part of Okinawa Island, and Iriomote Island

The island ecosystem components (except Iriomote) are characterised by the absence of predatory mammals, and are therefore very vulnerable to predacious invasive alien species (State Party of Japan 2019). The management of the property is contending with many invasive alien species as well as feral cats and several measures have been put in place to address these issues. The Indian Mongoose (Herpestes edwardsi), introduced in the last century, poses a major threat to endemic and threatened birds, reptiles and amphibians on Okinawa and Amami Islands including Amami Jay (Garrulus lidthi), Amami Rabbit (Pentalagus furnessi), Amami Woodcock (Scolopax mira), Amami Ishikawa’s Frog (Odorrana splendida) and the flightless Okinawa Rail (Gallirallus okinawae) (Watari et al. 2008; Ishida et al. 2015). On Okinawa, a fence has been put up to prevent the spread to the component part on the northern island, and on Amami Island, an effective eradication programme was implemented. In 2024, Japan's Ministry of the Environment declared that the mongoose had been eradicated from Amami Island (NHK 2024, The Asahi Shimbun 2024). However, the risk remain that the mongoose is re-introduced from Okinawa, where it still exists and poses a threat to rare and endemic species.
In addition, feral cats also pose a major threat, and have been found to prey on rare endemic species, including Amami rabbit (Pentalagus furnessi), Ryukyu long-haired rat (Diplothrix legata), three species of spiny rats, and Okinawa rail.

On Iriomote Island, although there are currently no confirmed feral cats, the risk of supply from islands such as Ishigaki Island cannot be eliminated, raising concerns over issues such as the competition, and disease transmission with Iriomote cats. Eradication and capturing programmes are in place both for mongoose and cats (State Party of Japan 2019).

Cane Toads (Rhinella marina) have been eradicated from Iriomote, but there is danger of reintroduction from the neighbouring island of Ishigaki, posing concerns to endemic and native species such as the Iriomote cat (Prionailurus bengalensis iriomotensis) and Crested serpent eagle (Spilornis cheela perplexus). In the Northern part of Okinawa Island, an alien species deer (Cervus nippon) was spotted inside a World Heritage site (Okinawa Times, 2024), raising concerns about the insufficient management of captive animals just outside the World Heritage site.
White-lipped Tree Frog (Polypedates leucomystax) that was once eradicated in Iriomote Island in 2019, was found in Tokunoshima Island in 2023. It risks the survival of endemic tree frog (Zhangixalus amamiensis), however it expands its distribution in eastern part of Tokunoshima Island (MoE, 2023, NHK 2024).
Several invasive plant species are also present in the property. There are action plans and local community efforts to control several invasive plant species, including “Mile-a-minute” (Mikania micrantha) and “Creeping Daisy” (Sphagneticola trilobata) (IUCN 2021; State Party of Japan 2019; WWF Japan 2009).

The illegal capture, collection and trade in plants, insects and reptiles are major problems, with serious impact on rare endemic species (IUCN, 2021). Contributing to the escalating collection activities is the development of a road network that has reached forest areas, thus providing easier access to spots where endemic species and rare species, likely in combination with increased tourism and visitation (State Party of Japan 2019). A report published by TRAFFIC International (Kanari and Xu, 2012) reviewed the illegal trade of Japanese endemic species. All five key species in the report (Ryukyu Black-breasted Leaf Turtle, Ryukyu Yellow-margined Box Turtle, Kishinoue’s Giant Skink, Kuroiwa’s Ground Gecko) are endemic to the property. The report concluded that there is an urgent need for increased conservation measures to be taken, especially with regard to freshwater turtles, and recommends that the effectiveness of Japan’s domestic law enforcement should be strengthened. Other species affected by illegal collection within the property include plants such as orchids and ginger, and insects, especially beetles (IUCN, 2021). In response to these recommendations, The Ministry of the Environment had been making progress in designating the nationally rare species of wild fauna and flora, with 158 species having been designated in the Amami and Okinawa regions by February 2024 (Yambaru Wildlife Conservation Center Ufugi Nature Museum, 2024). An Action Plan including night patrols and seasonal closure of roads to traffic at night has being implemented continuously.

Roads within and around the property poses a threat through traffic accidents involving animals, fragmentation of habitats, water contamination resulting from soil run-off at the time of construction, and alien species and illegal collectors gaining easier access (State Party of Japan 2019). Species such as the Amami Rabbit, Iriomote Cat, Okinawa Rail, Ryukyu long-haired rat and various snakes, frogs, newts are frequently killed on the roads that cross the property. Nine Iriomote Cats were killed in traffic accidents in 2018, out of an estimated population of only 100 cats (State Party of Japan, 2022). While there are numerous warning signs, speed bumps, speed limits of 30 km/h and underpasses, there are still a large number of threatened species being killed. Traffic accidents of Iriomote cats has been decreased by the efforts of management authorities and private organisations and no traffic accidents has been reported in 2023 and 2024 (Iriomote Wildlife Conservation Center 2025). Regarding other sites, although measures such as the installation of underpasses and intrusion prevention fences, calls for caution through signage, and the establishment of zebra zones for speed control have been implemented, traffic accidents of Okinawa Rail has been continued and 30 birds were died out of 32 traffic accidents in 2023 (Ufugi Yambaru Nature Center, 2024). Number of traffic accidents of Amami Rabbit recorded the highest number in 2023. In Amami-oshima Island, 147 animals died by traffic accidents and in 28 animals died in Tokunoshima Island (Ministry of the Environment, 2024). In regard to Amami Rabbit, it is considered that the rapid recovery in their population numbers, due to the success of mongoose and feral cat control measures, may be influencing the increase in traffic accidents. With increased tourism and vehicles in the protected areas, the risk of roadkill is anticipated to increase (IUCN 2021). It is also necessary to continue to raise awareness among local residents who use these roads for their daily lives.

Tourism, particularly on Iriomote, is having a negative impact on the natural values (roadkill, unsustainable use of water, increased visitation to less accessible parts of the island, illegal-/over-fishing). There is a lack of infrastructure (insufficient restrooms, limited rubbish disposal systems and no waste water treatment plants) to cope with the pressure, and the narrow island roads have a very limited capacity. However efforts are underway to address some of these issues, for example Taketomi Town is set to install environmentally friendly eco-toilets in the eastern part of Iriomote Island, with plans to start service in May 2025 (IUCN Consultation, 2025). Taketomi town, which Iriomote Island belongs to, revised its ordinance of Taketomi Town Tourism Guide in 2023 and designated the five trails including three falls and two mountains as important tourism destinations under the Ecotourism Promotion Act in 2024. Entry permit systems and limitation of visitor numbers for five trails was enacted in March 2025 (Taketomi Town, 2024).

Although no forestry operations are allowed within the property, there is some logging in the buffer zone. Regarding forest logging in the buffer zone, various regulations (such as limitations on the area of logging) and adherence to voluntary standards for forest operations that consider the natural environment are strictly enforced. In collaboration with forestry operators and relevant administrative agencies, information on the location and area of planned logging is shared annually. This is done under a cooperative system that ensures forestry operations are conducted with consideration for the conservation of biodiversity and the important habitats of rare species.

A substantial number of various infrastructure, including roads, power lines, concrete ditches, dams, antennas, culverts, concrete embankments, water abstraction and treatment plants, are present in the property. Especially the rivers on the islands have been subject to significant modification for water use and flood protection, posing concerns to negatively impact several endemic and threatened species dependent on natural freshwater processes and habitats, including threatened endemic fish species such as the Ryukyu Ayu (CR) (Ha et al. 2023, 2024; WWF Japan 2009).

In the US Jungle Warfare Training Center (JWTC), adjacent to the component on Northern Okinawa, training occurs with vertical take-off and landing transport aircrafts, which have been reported to cause wildlife disturbance, including to nesting birds like the threatened Okinawa Woodpecker (Itô, Miyagi. and Ota 2000; IUCN Consultation 2019). Furthermore, discussions between Japan and the United States have led to the 'Bilateral Cooperation for Conservation of the Natural Environment in the Northern Part of Okinawa Island, Designated as a World Heritage Site,' which was announced as a joint statement in 2023. This cooperation involves monitoring of rare species and control of invasive species (Ministry of the Environment, 2023).