Odorrana splendida is endemic to Amami-Oshima Island in the Nansei-shoto Islands, Japan where it occurs from about seal level to 694 m asl. The geographic range of the species is limited to this single location, an area of occupancy of 436 km2, and an extent of occurrence of 893 km2.
Habitat and Ecology
Odorrana splendida exclusively inhabits the upstream regions of montane torrents surrounded by primary broad-leaved evergreen forests. The frog requires such permanent lotic environments where temperature does not rise too high in summer. They breed through larval development in headstreams with abundant rock holes where the water flow is less. The breeding season of the species is from the end of January to May with its peak in February and March (Ministry of the Environment 2014).
Although the population size of this species is unknown, it is believed to have been in serious decline due to the reduction of its habitat and breeding ground (Ministry of the Environment 2014). Additionally, the population is fragmented because of road construction and habitat change caused by logging (Ministry of the Environment 2014). However, in 2006 it was reported that population is starting to recover as a result of eradication work of invasive mongoose, but the species' habitat and breeding ground have yet to be recovered (Watari et al. 2013).
Deforestation, along with the development around stream areas and road construction has reduced and fragmented the species’ habitats and deteriorated water quality. Predation by small Indian mongoose, Herpestes auropunctatus, which is a designated as invasive alien species in Japan, is also threatening the species. In addition, dam constructions in some stream areas are thought to damage the population.
The species is listed on the Red Data Book (Ministry of the Environment 2014) as Endangered. The species is designated as Endangered Wild Fauna and Flora of Kagoshima Prefecture by the ordinance and capture, damage, possession, and transfer is prohibited. It is also designated as a Prefectural Natural Monument.
Some of the habitat of this species are covered by National Natural Monument and by Amamigunto Forest Ecosystem Reserve which was established in April 2013. Further to strengthening the protection of the forests on the island, preparation for the designation of National Park is in progress.
Monitoring of the species is conducted by the Ministry of the Environment as part of the eradication work of the invasive mongoose Herpestes auropunctatus and it is subject to ex-situ conservation on a small scale at the Institute for Amphibian Biology, Hiroshima University. Mongoose eradication began in 1993 by local towns, in 1996 by the prefecture, and in 2000 by the Environment Agency (predecessor of MOEJ). The eradication work is ongoing in view of reaching the eradication target by 2022.
A recovery plan for the species is needed, which requires further research on the species' population size, distribution and trends. In addition, increased protection and management of the areas where the species occurs is required, along with education efforts to increase local awareness of the species' plight.
Red List Status
Odorrana splendida is endemic to Amami-Oshima Island in the Nansei-shoto Islands, Japan. Its extent of occurrence (EOO) is estimated to be less than 350 km2 and area of occupancy (AOO) is estimated to be less than 150 km2. The species is considered as inhabiting one location though its habitat is severely fragmented. The species is protected and control work of the invasive predator is ongoing. However, there is continuing decline in its area of occupancy, in the extent and quality of its habitat, and therefore, the species is listed as Endangered.
According to Kuramoto et al. (2011) this species was confused with Odorrana ishikawae prior to its naming.
IUCN SSC Amphibian Specialist Group 2015. Odorrana splendida. The IUCN Red List of Threatened Species 2015: e.T54314436A54316058. http://dx.doi.org/10.2305/IUCN.UK.2015-4.RLTS.T54314436A54316058.en .Downloaded on 15 December 2018