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Papuan Highland Brush Mouse

Abeomelomys sevia

French: Rat de Sevia / German: Hochland-Birstenmaus / Spanish: Raton de cepillo de altiplano de Papua

Other common names: Highland Brush Mouse, Highland Pogonomelomys, Menzies's Mouse, Papuan Abeomelomys

Taxonomy. Melomys sevia Tate & Archbold, 1935,

“Sevia, Cromwell Range, Huon Peninsula, Mandated Territory of New Guinea [= Morobe Province, Papua New Guinea]; 1400 m.”

Abeomelomys sevia was originally described in genus Melomys, but placed in new subgenus ( Pogonomelomys) by H.Rimmler in 1936. Shortly thereafter, Pogonomelomys was elevated to genus level by G. H. H. Tate and R. Archbold, an arrangement maintained until 1990 when J. I. Menzies subdivided the polyphyletic Pogonomelomys and placed sevia in a new,monotypic genus Abeomelomys . Molecular analyses suggest that closest affinity of Abeomelomys is with species of Brassomys and Pogonomelomys, and this is supported by morphological evidence as reviewed by G. G. Musser and D. P. Lunde in 2009. Geographic variation within A. sevia has not been subject to critical study. Name tate: Hinton, 1943 is available for populations on Central Cordillera of New Guinea should these prove distinct from typical sevia from geographically isolated mountains of Huon Peninsula. Currently regarded as monotypic, but in need of further assessment.

Distribution. Central Cordillera between Victor Emanuel and Bismarck ranges, and Cromwell Range on Huon Peninsula, E New Guinea.

Descriptive notes. Head-body 114-138 mm,tail 140-191 mm, ear 17-5-19 mm, hindfoot 24-26 mm; weight 40-1-65-5 g. The Papuan Highland Brush Mouse is a small arboreal murine with few special features. Fur on upperparts is thick and woolly, very soft, reddish brown or dark brown overslate-gray, paler on flanks and rump; fur on underparts dark gray tipped with grayish white orpale buff; boundary offlanks to belly coloration is diffuse. Head is relatively narrow, snout short but notbroadened, fur on cheek cream or pale yellow, ears short and rounded, dark gray and thinly furred; vibrissae fine and long, extending well past ears; eyes of normal size. Foreand hindfeet are unpigmented and covered in short white or pale buff hairs; forefeet with claws on four digits; hindfeet short and moderately broad, lacking webbing between digits, and with claws on all digits. Tail is long and narrow, usually dark brown above and below for entire length, but occasionally with irregular pale blotches; tail scales weakly overlapping, each scale with 3-5 hairs that are equal in length to two scales furred, overall appearance oftail being slightly hairy, end oftail with smooth pad 5 mm long on upper surface, presumably prehensile. Two mammae on each side, both inguinal. Cranium delicately built, with narrow rostrum and relatively small auditory bullae; molars small and narrow, with simplified, laminar crown pattern; upper incisor orange, lower incisor paler. Juvenile has much grayer fur on back and flanks but otherwise resembles adult. Spermatozoa with distinctive sperm head(15 pm) with broad lateral surface and long apical hook (10 pm), and lacking accessory ventral hooks.

Habitat. Most records are from evergreen tropical rainforest or forest edge, from lower montane rainforest at lower elevations to mossy upper montane rainforest above 2500 m; recorded at elevations of 1400-3560 m. In vicinity of Lake Aunde, on Mount Wilhelm (in Chimbu Province), members of the 1959 Sixth Archbold Expedition caught many Papuan Highland Brush Mice in grassland (a subalpine tussock community growing on ground too wet or too cold for forest) and fewer in forest.

Food and Feeding. Dentition of the Papuan Highland Brush Mouse suggests dietary focus on fruits and leaves.

Breeding. The only breeding data come from vicinity of Mount Erimbari in Eastern Highlands Province, where nine individuals, including seven females, were taken from leaf nests among dead fronds ofPandanus palms. Females were reproductively active at

weights above 59 g. Pregnant females, all with asingle embryo, were captured in October and December, coinciding with start of “wet season” in this area and with general breeding activity among other members of rodent community. One female captured in December was both lactating and pregnant, indicating possibility of multiple litters within single breeding season. There is one record of a Papuan Highland Brush Mouse being taken from a tree hollow. In tussock-grassland community on Mount Wilhelm,it presumably builds nests inside the tussock or possibly in low ferns and shrubs present as patches within the grassland.

Activity patterns. Although it clearly has a strong arboreal focus, the Papuan Highland Brush Mouse has been trapped on ground.

Movements, Home range and Social organization. Papuan Highland Brush Mice appear to nest individually and may be solitary outside any breeding activity.

Status and Conservation. Classified as Least Concern on The IUCN Red List. The lower part ofthis species’ elevational range in Central Cordillera of Papua New Guinea coincides with a zone of extensive habitat modification caused bylong-term subsistence agriculture. Habitats above 2500 m are much less affected by subsistence activities but, in places within the Papuan Highland Brush Mouse's range, they are potentially impacted bylarge-scale resource-development projects.

Bibliography. Brass (1964), Breed & Aplin (1995), Bryant (2013), Dwyer (1975), Ellerman (1941, 1949), Flannery (1995b), Flannery & Seri (1990), Helgen, Leary & Wright (2016h), Hinton (1943), Laurie (1952), Laurie & Hill (1954), Menzies (1990), Menzies & Dennis (1979), Musser & Carleton (1993, 2005), Musser & Lunde (2009), Rowe et al. (2008), Rummler (1936), Tate (1951), Tate & Archbold (1935b).