The King Rat, Uromys rex, is listed as Endangered on The IUCN Red List of Threatened Species™. It is known only from Guadalcanal in the eastern Solomon Islands, although indications are that it is absent from much of the island. Two other species of the genus once endemic to the island are now thought extinct.
Although first described in 1888, there have been very few records of the species and only a handful of specimens exist in museums. Consequently, virtually nothing is known of its natural history. It is arboreal, and is found in primary tropical, lowland and lower montane moist forest. It is thought to be threatened by loss of habitat through deforestation for timber and conversion of land for subsistence cultivation.
It is not known to be present in any protected areas and is currently not the subject of any conservation initiatives. The species is in urgent need of further research into its range and ecology, and would benefit from protection of its native habitat.