776.

Beccari’s Margareta Rat

Margaretamys beccarii

French: Rat de Beccari / German: Beccari-Margareta-Ratte / Spanish: Rata margarita de Beccari

Other common names: Beccari's Margaretamys, Spiny Lowland Margaretamys

Taxonomy. Mus beccaru Jentink, 1880,

Menado-Langkowah, Minahassa Region, north-eastern Sulawesi, Indonesia.

Margaretamys beccarii was assigned to Rattus until G. G.Musser in 1981 describedthe new genus Margaretamys, which was placed in the Pithecheir division by G. G. Musser and M. D. Carleton in 2005. In a phylogenetic study by M. Pages and colleagues in 2016, Margaretamys was sister to Lenothrix and put into a Dacnomys division; the Pithecheir division is not monophyletic. Additional studies are needed to determine if northern and central specimens of M. beccarii are actually the same species. Monotypic.

Distribution. N & C Sulawesi.

Descriptive notes. Head-body 117-147 mm, tail 150-212 mm, hindfoot 26-31 mm, ear 19-21 mm; weight 50-85 g. Beccari’s Margareta Ratis arboreal, with thick, short, and semi-spinous pelage. Upperparts are grayish brown. Ears are pale brown and slightly haired. Underparts are also semi-spinous. Color varies from cream to yellow, and dark ocherous buff. Color of underparts extends to cheeks and muzzle. Dark brown eye-rings and dark patch on rostrum give it a masked appearance. Feet are short and wide, brown above and with white sides and digits. Tail is very long and covered with hairs, increasing in length toward tip, which is penicillate and brown or white. Juveniles are gray above and creamy below, with dark gray ears, but otherwise they resemble adults. Cranium is small and stocky, rectangular in dorsal and ventral view. Some distinct features are short and narrow rostrum, and wide interorbital region. Incisors are yellow, and molars are bunodont. Females have three pairs of mammae. Chromosomal complement is 2n = 42, FN = 46.

Habitat. Lowland tropical evergreen rain forest from near sea level to elevations of c.1000 m. Beccari’s Margareta Rat has been collected in naturally disturbed riverside forest.

Food and Feeding. Diet consists of fruits from palms, understory trees ( Ficus, Moraceae), and woody vines (Genetum, Gnetaceae), moths, katydids, mantises, arthropods, snails, other invertebrates, and small lizards.

Breeding. Beccari’s Margareta Rats have 1-2 young/litter.

Activity patterns. Beccari’s Margareta Rat is arboreal and nocturnal. It has been mostly trapped in trees or woody vines in understory and apparently is the least ground-living species of Margaretamys .

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Vulnerable on The IUCN Red List. Beccari’s Margareta Rat is believed to be threatened by habitat degradation, resulting from deforestation for agriculture. Past and future population declines of more than 30% over a ten year period are inferred from rapid and extensive loss of lowland evergreen forest on Sulawesi. It is only known from a few areas, but it may be more widespread in other lowland forest (e.g. Mekkongga Range in south-eastern Sulawesi).

Bibliography. Boitani et al. (2006), Fabre et al. (2015), Mortelliti et al. (2012), Musser (1981a, 2014), Musser & Carleton (2005), Musser & Ruedas (2008c), Pages et al. (2016), Schenk et al. (2013).