This species is listed as Critically Endangered under B1ab(iii), because the species is currently only known from a single location which is Gag Island, where it has an estimated extent of occurrence (EOO) of just 56 km². Whilst nothing is known about its population and there have been no studies since its description, Gag Island has recently become a site of a large surface nickel mine that covers approximately one third of the island, therefore it is inferred that this activity is reducing the quality and quantity of available forest habitat of the species. Surveys of neighbouring islands are a high priority, along with studies of the status of the species on Gag Island itself.

This species is known from Gag Island in West Papua, Indonesia, but could potentially be found on the other islands in the area (Maryanto et al. 2010).

There is no information regarding the population status of Rattus nikenii.

It presumably lives in ultrabasic, evergreen valley forests on the island (Maryanto et al. 2010).

The Gag Island Project is a surface nickel mine that covers the central block of the island extending from the west coast to the east coast in a south easterly direction, covering approximately one third of the island (Minadat.org 2022).

Use and trade information is unknown.

Although Gag Island has been declared a ‘protected forest’ under Indonesian law, the government made exemptions for nickel mining operations there. Urgent surveys of Gag Island and neighbouring islands are needed.