550.

Gray-bellied Mouse

Mus triton

French: Souris triton / German: Triton-Zwergmaus / Spanish: Raton de vientre gris Other common names: Gray-bellied Pygmy Mouse

Taxonomy. Leggada triton Thomas, 1909,

“Kirui, [Mount] Elgon, British East Africa [= Kenya]. Alt. 6000" [= 1830 m].”

As currently delineated, this is a complex comprising at least two species, as demonstrated by the work of J. M. Lamb and colleagues in 2014 and A. Monadjem and colleagues in 2015. Large gray-bellied specimens attributed to M. triton form two highly divergent molecular and chromosomal clades: on the one hand, from Tanzania, Malawi, and Mozambique (with chromosomal complement of 2n = 20-22, FN = 34); and, on the other, from DR Congo (with 2n = 32, FN = 34. Monotypic.

Distribution. Extreme S South Sudan, S Ethiopia (Bale Mts), NE DR Congo, and from Uganda and Kenya SW & S to Angola, Zambia, WC Mozambique, and Malawi.

Descriptive notes. Head-body 56-84 mm, tail 42-65 mm, ear 8-14 mm, hindfoot 14-17 mm; weight 8-16 g. Small mouse with shorttail. Fur is darkish brown flecked with buff or yellow above, darker on rump and brownish on flanks; below medium gray to grayish white, sometimes tinged with yellow. Dorsal and ventral colors sharply demarcated by yellowish stripe in adults. Tail is short (¢.70% of head-body length), dark above and paler below. Ears are dark with short sparse brownish hairs. Feet are brownish or yellowish. Females have five pairs of nipples.

Habitat. Occurs in a wide range of grassland, wetland, forest, scrub, and agricultural habitats at elevations of 1000-3500 m.

Food and Feeding. The Gray-bellied Mouse is omnivorous, but primarily insectivorous. In stomachs analyzed in Malawi and DR Congo, beetles were the main insects taken while vegetable matter was mostly whitein color, representing grains such as sorghum.

Breeding. Reproduction is confined mostly to the wet season or early dry season, with two or three litters per season. Litter size 2-7.

Activity patterns. Gray-bellied Mice are terrestrial, and both nocturnal and diurnal.

Movements, Home range and Social organization. Gray-bellied Mice make nests at the base of grass clumps.

Status and Conservation. Classified as Least Concern on The IUCN Red List.

Bibliography. Delany (1975), Dieterlen (1967a), Hanney (1965), Happold (2013a), Happold & Happold (1989a, 1989b), Lamb et al. (2014), Monadjem et al. (2015).