Large Mindoro Apomys

description

Comparisons. Apomys veluzi sp. nov. (Fig. 2 B) is easily distinguished externally from A. gracilirostris (Fig. 2 A). The former is smaller in all respects; e. g., HB x ̄ = 129 mm vs. 142 mm, BOL x ̄ = 31.79 mm vs. 34.78 mm (Tables 1 and 4). The pelage of A. gracilirostris is dark brown, slightly less dark ventrally, with a hint of ochraceous wash dorsally and ventrally, and short, black guard hairs are visible dorsally; that of A. veluzi sp. nov. is a rich ochraceous brown dorsally and pale cream ventrally with a slight ochraceous wash. Ears of A. gracilirostis are both absolutely and proportionally to HB shorter than those of A. veluzi sp. nov. (Table 1), and are dark brown vs. medium brown. Hair behind the ears is the same color and length as other dorsal pelage; that of A. veluzi sp. nov. is pale sandy-orange, slightly longer than surrounding fur. On A. gracilirostris, dark brown fur extends onto the tops of fore and hind feet; forefeet are lightly pigmented ventrally, hind feet are dark ventrally; on A. veluzi sp. nov., the fore and hind feet are covered dorsally with fur that is pale cream, and with pale skin ventrally. Forefeet of A. gracilirostris have sturdy digits and claw

Three new species of Philippine forest mice (Apomys, Muridae, Mammalia), members of a clade endemic to Mindoro Island

description

Measurements. Tables 1 and 4. Specimens examined. (n = 25). Philippines: Mindoro Island: Oriental Mindoro Province: Baco Municipality: 4.75 km N, 0.8 km E Mt. Halcon peak, 1650 m elevation, 13.30687 o N, 121.0009 o E (FMNH 222069 – 222080, 222316 – 222321); 0.95 km N, 1.45 km W Mt. Halcon peak, 2150 m elevation, 13.27222 o N, 120.980 o E (FMNH 222064); 0.5 km N, 1.1 km W Mt. Halcon peak, elevation 2310 m, 13.26745 o N, 120.9838 o E (FMNH 222065 – 222068, 222314, 222315).

Three new species of Philippine forest mice (Apomys, Muridae, Mammalia), members of a clade endemic to Mindoro Island

diagnosis

Diagnosis and Description. For an extensive description, see Ruedas (1995). We note the following features that together diagnose this species: large size among Megapomys, basioccipital length x ̄ = 34.8 mm (33.6 – 36.1 mm, Table 4); HB x ̄ = 142 mm (range 134 – 150 mm), weight = 83 g (range 70 – 102 g; Table 1); pelage dark brown dorsally and ventrally, slightly paler ventrally with slight ochraeous wash at tips (Fig. 4 A); mystacial vibrissae up to 55 mm long; no evidence of a postauricular tuft of elongated or pale hair; tail dark brown dorsally and medium brown ventrally, often with a white tip (1 – 15 mm), and with short but visible hairs along its entire length dorsally and ventrally; tail proportionately longer than most Megapomys, TV / HB about 1.11 (Table 1), thick at the base and tapering to tip; ears dark brown and short (x ̄ = 19.5 mm) absolutely and relative to HB (Table 1); forefeet with dark hairs extending to base of digits dorsally, with unusually long, sturdy digits and claws; hind feet long (x ̄ = 38.5 mm) but broad and proportionately slightly short (Table 1) with six large plantar pads, heavily pigmented ventrally; skull and teeth as described above for the gen

Three new species of Philippine forest mice (Apomys, Muridae, Mammalia), members of a clade endemic to Mindoro Island

distribution

Distribution and Ecology. Known only from Mt. Halcon, northern Mindoro (study area 3 in Fig. 1). Ruedas (1995) documented this species from 1250 m to 1950 m elevation; we recorded them from 1650 m, 2150 m, and 2310 m (Fig. 1 B), in old-growth mossy forest dominated by gymnosperms (e. g., Dacrycarpus, Falcatifolium, Phyllocladus, and Podocarpus) and myrtles (e. g., Leptospermum and Syzygium), where leaf litter and humus formed thick layers on the ground and epiphytes were abundant on the trees. We did not capture them at our sampling areas from 500 m to 1110 m (Fig. 1 B), in regenerating forest over limestone, regenerating lowland forest, and montane forest, at all of which leaf litter and humus were virtually absent. Other native small mammals we documented from 1650 - 2310 m were Crocidura mindorus, Anonymomys mindorensis, Apomys microdon, Apomys musculus, Chrotomys mindorensis, Maxomys sp., and Rattus mindorensis. Although three non-native species (Suncus murinus, Rattus exulans, and Rattus tanezumi) were present at lower elevations, they were absent where A. gracilirostris occurred. As noted by Ruedas (1995), “ the gracile skull, long rostrum, reduction in relative size of upper

Three new species of Philippine forest mice (Apomys, Muridae, Mammalia), members of a clade endemic to Mindoro Island