220.

Mountain Shrew Mouse

Soricomys montanus

French: Rat de Balete / German: Berg-Spitzkopfmaus / Spanish: Raton musarana de montana

Other common names: Southern Cordillera Shrew Mouse

Taxonomy. Soricomys montanus Balete et al., 2012,

east of South Peak Mt. Data, Mountain province, Luzon Island, Philippines.

One of the most recently discovered species of the genus, S. montanus is very similar in morphology to S. kalinga, but some morphometric and molecular differences allow its separation at species level. Phylogenetically, S. montanus belongs to same clade as S. kalinga . Monotypic.

Distribution. S portion of Cordillera Central, N Luzon I, Philippines.

Descriptive notes. Head-body 93-103 mm, tail 85-98 mm, ear 13-15 mm, hindfoot 22-26 mm; weight 23-31 g. The Mountain Shrew Mouse is a small shrew mouse with a slender sturdy snout and small eyes. Dorsal pelage is a dark reddish brown, being longer than the ventral pelage, which is it not sharply demarcated from. Dorsal hair is tricolored, being medium gray for the basal three-fourths, followed by a band of dark gray and a reddish brown tip. Ventral pelage is shorter and a paler orange brown. Eyelids are edged in black and surrounded by a pale reddish brown ring of short fur. Ears are small, rounded, and dark gray; vibrissae are moderately long and extend beyond the ears. Tail is relatively long for the genus (82-102% of head-body length) and is a dark reddish brown coloration. Hindfeet are slender with long digits and long claws that are opaque in color, being grayish brown dorsally and darker ventrally. Pollex is reduced to a small stump with anail rather than a claw. Forefeet are pale grayish dorsally and ventrally. Skull has a short-tapered rostrum that is long compared to other Soricomys, a large orbito-temporal length, and a short post-palatal region compared to its congeners. Females bear twopairs of inguinal mammae. Chromosomal complement has 2n = 44, FN = 52.

Habitat. Primary and secondary montane forest and degraded patches ofmossy forest from 1950 m to 2690 m.

Food and Feeding. Diet is composed of earthworms and probably other small invertebrates. Stomach contents ofsix individuals contained arthropod remains, although only two of them contained earthworms. Mountain Shrew Mice forage on paths in the leaflitter.

Breeding. On Mount Amuyao, two females with large mammae and four males with scrotal testes were captured in March. On Mount Data and Mount Pulag, males were captured with scrotal testes in March and April, respectively.

Activity patterns. Mountain Shrew Mice are diurnal and terrestrial.

Movements, Home range and Social organization. No information.

Status and Conservation. Not assessed on The IUCN Red List. The Mountain Shrew Mouse is widespread and tolerant of human activities.

Bibliography. Balete et al. (2012), Heaney, Balete & Rickart (2016).