810.

Dusky Long-footed Rat

Tarsomys apoensis

French: Rat de I’Apo / German: Dunkle Fersenratte / Spanish: Rata de pies largos oscura

Other common names: Dusky Tarsomys, Long-footed Rat

Taxonomy. Tarsomys apoensis Mearns, 1905,

Mount Apo, 2058 m, Mindanao Island, Philippines.

Tarsomys was sometimes considered a subgenus of Rattus, but G. G. Musser and L.

R. Heaney in 1992 treated it as a distinct genus and put Tarsomys into the New Endemics in the Philippine Muridae with Limnomys and Rattus everetti . This relationship was confirmed by S. A. Jansa and colleagues in 2006 and P.-H. Fabre and colleagues in 2013 who found well-supported clade including Philippine taxa Limnomys, Tarsomys, and Rattus everetti —one of three species of Rattus endemic to the Philippines. There is a still an undescribed Tarsomys species on Sibuyan Island. Monotypic.

Distribution. Highlands of Mindanao I (including Mt Malindang, Mt Kitanglad, and Mt Apo), Philippines.

Descriptive notes. Head-body 135-156 mm, tail 116-126 mm, ear 20-23 mm, hindfoot 31-34 mm; weight 65-72 g. The Dusky Long-footed Rat is medium-sized, with moderately long face and short tail, much shorter than head-body length. Pelage is long and moderately soft. Hindfeet are long and slender, with six plantar pads and sometimes with small tubercles. Claws of forefeet are elongated and somewhat enlarged. Upperparts are dark chestnut brown; underparts are slightly paler, dark brown, washed with buff. Ears are dark brown, and tail is dark brown for its entire length. Females have three pairs of mammae. The Dusky Long-footed Rat might be the ecological equivalent of the Sulawesian Common Hill Rat ( Bunomys chrysocomus), which it superficially resembles in some morphological traits. Chromosomal complement is 2n = 42, FN = 61-62.

Habitat. Old-growth transitional montane/mossy forest and mossy forest at elevations of 1550-2800 m.

Food and Feeding. The Dusky Long-footed Rat is predominantly insectivorous. Captive individuals preferred earthworms, small scarab beetles, and calliphorid flies but did not acceptfruits, cockroaches, or coconut bait.

Breeding. One female Dusky Long-footed Rat had four embryos.

Activity patterns. Dusky Long-footed Rats are equally active day and night. On Mount Kitanglad, all specimens were captured in traps set along runways and holes among mossy root tangles. Their color (chestnut upperparts) relates to diurnal activities, like other forest-dwelling murids from the Philippines and Sulawesi such as the Isarog Shrew Mouse ( Archboldomys luzonensis), the Diurnal Sulawesian Shrew Rat ( Melasmothrix naso), and the Sulawesian Shrew Mouse ( Crunomys celebenss).

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Least Concern on The IUCN Red List. Although the Dusky Long-footed Rat is known mainly from isolated records, it isclassified as Least Concern because of its presumably wide distribution. It is moderately common and likely to have stable overall population in its high-elevation montane/mossy forest habitats thatare not declining.

Bibliography. Boitani et al. (2006), Fabre et al. (2013), Heaney & Tabaranza (2016), Heaney, Balete et al. (1998), Heaney, Dolar et al. (2010), Jansa et al. (2006), Misonne (1969), Musser & Carleton (2005), Musser & Heaney (1992).