Apomys musculus Miller 1911

Apomys musculus Miller 1911, Proc. U. S. Natl. Mus ., 38: 403.

Type Locality: Philippines, Luzon Isl, Benguet, Baguio, Camp John Hay, 5000 ft (1524 m).

Vernacular Names: Least Philippine Apomys.

Distribution: Philippines: Dinagat, S and N Luzon, and Mindoro (Heaney et al., 1998).

Conservation: IUCN – Lower Risk (lc).

Discussion: Included within Apomys abrae hylocetes Group by Musser (1982 b). Standard karyotype (2n = 42, FN = 52; Rickart and Musser, 1993) very similar to that of A. datae (Rickart and Heaney, 2002) . Three species may be represented in what is now called musculus: typical musculus from N Luzon, a separate species in S Luzon, and another on Mindoro (Heaney, pers. comm.). Altitudinal distribution and ecological data summarized by Balete and Heaney (1997) and Heaney et al. (1999). Judged by phylogenetic analyses of mtDNA cytochrome b sequences, A. musculus is most closely related to two undescribed species and A. microdon (see that account).