167.

Mount Amuyao Tree Mouse

Musseromys inopinatus

French: Rat de 'Amuyao / German: Mount-Amuyao-Bergwaldmaus / Spanish: Raton arboricola de Amuyao

Taxonomy. Musseromys inopinatus Heaney et al., 2014,

1 km N, 1 km W of Mt. Amuyao Peak, Barlig, Mountain Province, Luzon Island, Philippines.

This recently described species was characterized using morphology, skull morphometrics and cytochrome-b data. A 2015 molecular study by D. S. Balete and colleagues shows this species to be sister to a clade consisting of M. anacuao and M. beneficus . Monotypic.

Distribution. Known only from Mt Amuyao, Luzon I, Philippines.

Descriptive notes. Head-body 78 mm, tail 85-88 mm, ear 17 mm, hindfoot 18- 19 mm; weight 17-19-5 g. The Mount Amuyao Tree Mouse is a rather small mouse that is rusty brown dorsally and buffy reddish brown ventrally. From the large head, two long sets of vibrissae emerge. Tail is longer (111%) than head-body length and ends with a tiny tuft of long hairs (c.10 mm long). Feet are pale (nearly white with some brown hairs dorsally) and elongated, with hindfeet being broad with moderately sized plantar pads. Forefeet have a very short pollex with a small, convex nail in contrast to the long curved claws of the other digits. Ears are long and rounded, without the bluntly pointed tip of the Mount Banahaw Tree Mouse ( M. gulantang). Skull is relatively large with a substantially broader interorbital region, a greater mastoid breadth, long and broad incisive foramin, wide zygomatic plate, long molar row and rostrum, and moderately short nasal. The anterior of the incisors are a pale orange rather than a medium orange that occurs in the Mount Banahaw Tree Mouse. Females bear two pairs of inguinal mammae.

Habitat. Primary and secondary mossy montane forest at 1650-2300 m, where oaks, laurels, myrtles, and podocarp trees are covered by abundant epiphytes, moss, orchids, and ferns.

Food and Feeding. Little is known, but the snap traps used to capture the specimens were baited with slices offried coconuts covered in peanut butter.

Breeding. Young adult and subadult males (with abdominal testes) and females (with inperferated vaginas) were captured in March and adult and young adult males with scrotal testes were collected in March and April, respectively.

Activity patterns. Individuals trapped were 0-5-5 m aboveground, on tree trunks, branches, or vines; they were taken at night or in late afternoon.

Movements, Home range and Social organization. No information.

Status and Conservation. Not assessed on The IUCN Red List. The Mount Amuyao Tree Mouse is known only from a few specimens collected from the type locality.

Bibliography. Balete et al. (2015), Heaney, Balete & Rickart (2016), Heaney, Balete, Rickart, Veluz & Jansa (2014).