Ryukyu mole (Mogera uchidai)

Also known as: Senkaku mole
Synonyms: Nesoscaptor uchidai
GenusMogera (1)
SizeHead-body length: 130 mm (2)
Tail length: 12 mm (2)

Classified as Data Deficient (DD) on the IUCN Red List (1).

The single existing specimen of the Ryukyu mole was captured in 1979, but it was not until 1991 that scientists described it and recognised a number of unique morphological features, in particular characters of the skull and dentition, that distinguished it from other Japanese moles (3) (4). The Ryukyu mole has dark greyish-brown fur, which is paler on the underparts (2), a relatively short tail, and nostrils that are directed outwards (5). Whilst some believe the Ryukyu mole should be placed in its own genus, Nesoscaptor, others believe it is more closely related to Mogera insularis (insular mole) from Taiwan (4), and thus should be called Mogera uchidai (5).

The Ryukyu mole is only known from the west coast of Uotsuri-jima, the largest of the Senkaku Islands, in the East China Sea (5).

The preferred habitat of the Ryukyu mole is not known (6); the single specimen was collected from a grassy field (5).

As the Ryukyu mole is currently only known from a single specimen, nothing is known about this species’ behaviour, biology or ecology (6).

Despite being so poorly known, it is clear that this species, like others endemic to Uotsuri-jima, is threatened by the introduction of goats (Capra aegarus) (3) (7). A pair of goats was deliberately introduced to the island in 1978. Since then, the goat population has increased to over 300 individuals (8), a population size which can have a significant impact on an island measuring only 3.8 square kilometres (7). The natural habitat of the island has been obviously damaged by the goats’ foraging and trampling, with bare patches appearing in the island’s vegetation (3). Without action, the increasing goat population may impact the island ecosystem to such an extent that many endemic species will be pushed to extinction in the near future (3).

The Red List of Japan classifies the Ryukyu mole as Critically Endangered (9), but unfortunately, this listing has not yet resulted in any conservation action. The sovereignty of the Senkaku Islands is disputed, with Japan, China and Taiwan all claiming them as national territory, and this political conflict has made it almost impossible to conduct research on the islands, let alone implement conservation measures (3) (7). Action to prevent the further destruction of Uotsuri-jima’s unique biodiversity is urgently needed (3), but until the human conflict is resolved, the Ryuku mole will be left to slip further towards extinction.

For further information on the Ryukyu mole see:

Authenticated (01/05/08) by Yasushi Yokohata, Faculty of Science, University of Toyama, Japan.

  1. IUCN Red List (December, 2009)