208.

Large Cordillera Shrew Mouse

Archboldomys maximus

French: Rat de la cordillere Centrale / German: Grof 3e Archboldmaus / Spanish: Ratén musarana de Cordillera

Other common names: Cordillera Archboldomys

Taxonomy. Archboldomys maximus Balete et al., 2012,

“Philippines: Luzon Island: Mountain Province: Barlig Municipality, Mt. Amuyao peak, 1885 m elevation, 17-02929°N, 121-12466°E.”

Genus Archboldomys may belong to a clade of murines that also includes Apomys, Chrotomys and Soricomys . Two species formerly included in Archboldomys are now placed in Soricomys ( S. kalinga and S. musseri). A. maximus was newly collected in 2007. Monotypic.

Distribution. Known only from the upper slopes of Mt Amuyao, NC Luzon, Philippines; it is probably more widespread on nearby peaks in the S Cordillera Central.

Descriptive notes. Head—body 102-116 mm, tail 90-108 mm, ear 18-21 mm, hindfoot 29-33 mm; weight 40-55 g. Archboldomys species are small terrestrial murines having short tail with conspicuousscales, each with three short hairs; small forefeet with small, flat nail on first digit and relatively short, robust claws on the other four; narrow hindfeet with six plantar pads and relatively short claws on all five digits; small, dark ears with dense cover of fine dark hairs; relatively small eyes; soft, dense and slightly woolly fur that is dark and of same color on all parts of body; thin rostral vibrissae that extend back to slightly behind ears; mammae two on each side, both inguinal; and skull delicately constructed, but with moderately large, cuspidate molars, and a distinctively

upturned tip to nasal bones. The Large Cordillera Shrew Mouse is the bigger of the two Archboldomys, and is further distinguished by its longer, dark grayish-chestnutfur, its absolutely and relatively longertail and hindfeet, its smaller tail scales (18-24 rows/ cm), and slightly larger and more cuspidate molars.

Habitat. Evergreen tropical forests, including primary montane forest and mossy forest types and in high-quality regenerating forest, at elevational range of 1885-2690 m.

Food and Feeding. Stomach contents ofsix individuals all included earthworms; three of the six also held centipedes (Geophilomorpha), and four contained a few fragments of insect exoskeletons (body and integument of adults and larvae). Trapping with live earthworms as bait was marginally more successful compared with fried coconut as bait.

Breeding. Captures made in March indicate breeding activity at that time: one of four adult females was pregnant with a single embryo and one placental scar (from a previouslitter), and five of six males had swollen testes that were quite large (up to 10 mm x 7 mm) relative to body size.

Activity patterns. D. S. Balete and coworkers reported slightly more daytime captures than crepuscular or night-time captures.

Movements, Home range and Social organization. No information.

Status and Conservation. Not yet assessed on The IUCN Red List. The high-elevation habitats on Mount Amuyao are not contained within a protected area but are not currently threatened by any anthropogenic disturbance. Surrounding parts of the southern Central Cordillera remain unsurveyed. The Large Cordillera Shrew Mouse is reported as being moderately common on Mount Amuyao.

Bibliography. Balete, Heaney & Rickart (2013), Balete, Rickart et al. (2012), Heaney, Balete & Rickart (2016), Rickart, Balete et al. (2016), Rickart, Heaney et al. (2011), Schenk et al. (2013).