This species belongs to subgenus Coelomys Thomas, 1915. Ellerman (1961) listed two subspecies, namely Mus mayori mayori (Thomas, 1915) and Mus mayori pococki (Ellerman, 1947).

This species is assessed as Vulnerable because it has a relatively small extent of occurrence (EOO = 8,585 km²), the population is severely fragmented (more than half of the individuals appear to be distributed across small, disconnected and isolated forest patches), and there is continuing decline in the extent and quality of its habitat. Population monitoring would be beneficial.

This species is endemic to Sri Lanka where it is known from the Central Province, Southern Province, Western, Uva and Sabaragamuwa Province (Phillips 1935, Molur et al. 2005, W.L.D.P.T.S. de A. Goonatilake in litt. 2005). It occupies an altitudinal range of 165 to 2,310 m asl and is widely distributed (Molur et al. 2005), but severely fragmented and more than half of all individuals occur in small and isolated patches. Small mammal surveys between 2006 and 2009 demonstrated that the species was found in 15 forest study areas (Wijesinghe 2012).

During surveys from 2006–2009 across 15 rainforest study areas, the species was found in all sites and was one of the two predominant species trapped (Wijesinghe 2012). In Kanneliya from October 2006 to February 2007, and from June to August 2007 in Sinharaja, Yagirala, and Walankanda forests, a total of 117 individuals of M. m. pococki were captured from the four different forest reserves (Ratnaweera et al. 2010). Nonetheless, populations appear to be fragmented across disconnected and shrinking forests, and it is thought that the population is declining.

It is a nocturnal and fossorial species. It occurs in tropical and sub tropical montane, lowland evergreen forest; primary and secondary forest. It has been found to occupy wet undergrowth in low country, wet and mountain wet zones, rainforests, and wet patana grasslands (Molur et al. 2005). It is restricted to forest patches and does not use the plantations and agriculture farm settlements surrounding these patches (S. Goonatilake pers. comm. 2019).

This species is threatened by deforestation due to expansion of farmland, human encroachment, and predation by domestic animals (e.g. cats) (Molur et al. 2005). Natural forest cover has been depleted at a rate of 7,700 ha per year between 2010 and 2015 in Sri Lanka (Premakantha et al. 2021)

The species is protected by The Fauna and Flora Protection (Amendment) 45 Act, No.22 of 2009. It has been recorded in numerous protected areas (Wijesinghe 2012). It is little-studied, so research of its population, threats and ecology would be beneficial.