192.

Camiguin Forest Mouse

Apomys camiguinensis

French: Apomys de Caminguin / German: Camiguin-Philippinenwaldmaus / Spanish: Ratén de bosque de Camiguin

Other common names: Camiguin Apomys

Taxonomy. Apomys camiguinensis Heaney & Tabaranza, 2006,

“Barangay Kital-is, Sagay Municipality, 2 km N, 62 kw W Mahinog, 1000 m elevation, Camiguin Province, Camiguin Island. 9°9.5°N, 124°43.5’E.”

A member of subgenus Apomys, A. camiguinensis was newly collected in 1994 and, prior to formal description, was referred to as“ Apomys sp. D .” Molecular evidence suggests possible special affinity with A. Aylocoetes and A. insignis from Mindanao Island, and with an undescribed species of Apomys from Leyte and Biliran. Monotypic.

Distribution. Camiguin I, S Philippines.

Descriptive notes. Head-body 106 mm, tail 140-160 mm, ear 18-20 mm, hindfoot 31-34 mm; weight 33-48-5 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, vibrissae on snout very elongate and, folded back, reach to shoulder or beyond,relatively large and thinly furred ears, reduction to two mammae on each side, both inguinal, and a simplified molar pattern with cusps united into transverse laminae. Members of subgenus Apomys are small, long-tailed species active primarily in canopy. The Camiguin Forest Mouse is a medium-sized species of subgenus Apomys . Fur on upperparts, flanks, and outer surfaces of limbs is dense and very soft, without spines or stiff hairs, rich brownish russet with small amount of “salt-andpepper” speckling; fur on underparts and inside of limbs is usually nearly white with a buffy or pale russet wash, sometimes with pure white blaze on chest; colors of upperside and lower parts merge gradually; ears are darkly pigmented and with short hairs on outer surface; eyes ringed with thinly furred pale skin. Dark fur of limbs extends onto upper surfaces of foreand hindfeet, but digits are unpigmented and covered with shorter white hairs; hindfeet relatively elongate but somewhat broader than those of some other members of subgenus Apomys, undersurface lightly pigmented, plantar pads small and well separated, hallucal pad short but well forward, digits moderately long. Tail is relatively long (averaging slightly longer than head-body length), sharply bicolored, dark brown above and white below for entire length, tail scales conspicuous and relatively large, in 12-125 rows per cm near tail base, and usually with three short hairs per scale, hairiness increasing toward tail tip but without terminal brush. Cranium very similar to those of other members of subgenus Apomys, but braincase and orbit unusually long, and rostrum long but robust.

Habitat. Known only from evergreen tropical rainforest on Mount Timpoong,at elevations of ¢.1000-1400 m. It was common in 1994-1995 in disturbed lowland rainforest at 1000 m and in undisturbed montane forest at 1275 m, and less so in primary mossy forest at 1200-1400 m. It is likely to occur on other forested peaks on Camiguin Island, but is probably absent from extensively deforested areas below 1000 m.

Food and Feeding. No information.

Breeding. A pregnant female captured in May 1994 had a single embryo, while two other adult females captured in May 1994 and March 1995 each had two placental scars. Adult females with enlarged teats weighed 37-5-42 g, whereas nulliparous females weighed up to 35 g. Adult males with scrotal testes weighed 36-5-48 g, whereas immature males with abdominal testes weighed 34 g or less.

Activity patterns. All individuals captured in 1994-1995 were trapped on the ground among roots or beneath fallen and rotten logs, and at night. The Camiguin Forest Mouse is likely to be scansorial or arboreal, as are other species of subgenus Apomys .

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Vulnerable on The IUCN Red List. The Camiguin Forest Mouse was locally abundant in 1994-1995 in both primary and disturbed habitats but its current status is unknown. Its known population is within Timboong Hibok-Hibok Natural Monument.

Bibliography. Heaney (2017), Heaney & Tabaranza (1997 2006a, 2006b), Heaney et al. (2011), Heaney, Tabaranza, Balete & Rigertas (2006), Justiniano et al. (2015), Musser & Carleton (2005).