200.

Large Forest Mouse

Apomys magnus

French: Grand Apomys / German: GroRe Philippinenwaldmaus / Spanish: Raton de bosque grande

Other common names: Large Apomys, Large Banahaw Forest Mouse

Taxonomy. Apomys magnus Heaney et al., 2011,

“Philippines: Luzon Island: Quezon Province: Tayabas Munic.: Barangay Lalo: Mt. Banahaw, Hasaan, 1250 m; 14°3’44”N, 121°31'S"E.”

Apomys magnus, newly collected in 2005,is a member of subgenus Megapomys. Genetic evidence indicates that it is well differentiated from all other known Megapomys; its closest relatives may be A. awrorae and A. zambalensis . It is narrowly sympatric with A. banahao at ¢.1465 m on Mount Banahaw. Monotypic.

Distribution. Recorded only from Mt Banahaw, Luzon I, Philippines; possibly present on adjacent Mt San Cristobal.

Descriptive notes. Head-body 137-160 mm, tail 133-154 mm, ear 21-23 mm, hindfoot 37-41 mm; weight 92-128 g. Species of Apomys are soft-furred, small to medium-sized murines with relatively unspecialized body form; distinguished from other Philippine murines by a distinctive suite of features, including long, narrow hindfeet, thinly furred tail, unreduced eyes, relatively large and thinly furred ears, vibrissae on snout very elongate and, folded back, reach to shoulder or beyond, reduction to two mammae on each side, both inguinal, and a simplified molar pattern with cusps united into transverse laminae. Members of subgenus Megapomys are larger, shorter-tailed species that are active primarily on ground; in most forest habitats across Luzon Island, they are the most abundant terrestrial mammal in any local community. The Large Forest Mouse is the largest Megapomys, with fur on upperparts moderately long and dark brown with conspicuous black tipping, further accentuated by short black guard hairs, body hairs with gray bases; fur on underparts and inside of limbs medium gray at base with white tipping; upperside and underside with sharply defined boundary. Dark fur of forelimbs extends forward as narrowing strip to forefeet, but digits are unpigmented and covered with short white hairs; dark fur on forelimb stops above ankle, hindfeet unpigmented and entirely covered with short white hairs; hindfeet relatively long and stout, undersurface darkly pigmented except on some pads, post-hallucal pad elongate, other pads moderately large but well separated, digits relatively long and robust. Tail is moderately long (averaging 96-99% of head-body length), dark brown above and unpigmented or white below for entire length. Cranium is larger than that of all other Megapomys, with robust, flaring zygomatic arches, long,stout rostrum, and long molar rows.

Habitat. Abundant in evergreen tropical montane forests, including both lowland and montane types distinguished in Philippine ecological literature, at elevations of 765— 1465 m. Not captured at or below 600 m or above 1465 m, despite intensive trapping in these elevational zones Food and Feeding. [.. R. Heaney and colleagues reported in 2016 that Large Forest Mice “showed a weak preference for live earthworms rather than fried coconut but probably are best considered omnivorous.”

Breeding. One pregnant female carried three embryos. No other information.

Activity patterns. Heaney and coworkers reported that “all were captured at night, and all were captured on the ground surface (not in trees).”

Movements, Home range and Social organization. No information.

Status and Conservation. Not assessed on The IUCN Red List. Most of the known distribution ofthis species lies with the Mounts Banahaw-San Cristobal Protected Landscape. The Large Forest Mouse is the most commonly trapped small mammal in oldgrowth forest or mature regrowth at mid-elevations on Mount Banahaw. In heavily disturbed forest, at same elevations,it is less abundant than the Philippine Forest Rat ( Rattus everetti).

Bibliography. Heaney, Balete, Rickart et al. (2011), Heaney, Balete & Rickart (2016), Heaney, Balete, Rosell-Ambal et al. (2013), Justiniano et al. (2015).