431.

Dybowski’s Three-toed Grass Rat

Mylomys dybowskii

French: Mylomys de Dybowski / German: Dybowski-Furchenzahnratte / Spanish: Rata de hierba de tres dedos de Dybowski

Other common names: African Groove-toothed Rat, Common Groove-toothed Rat, Common Mylomys, Dybowski’s Mylomys, Mill Rat

Taxonomy. Golunda dybowski Pousargues, 1893,

Kemo River, French Congo (= Central African Republic).

This species is monotypic.

Distribution. Patchily distributed in tropical Africa from SE Guinea (Mt Nimba) E to C Kenya and S to N Malawi.

Descriptive notes. Head-body 122- 194 mm, tail 104-180 mm, ear 14- 25 mm, hindfoot 29-37 mm; weight 46— 190 g. Large and stoutly built, Dybowski’s Three-toed Grass Rat has coarse dark pelage and thick tail, similar to Arvicanthis and Pelomys . Fur is brown with heavy black streaking above, contrasting sharply with off-white on belly, lower cheeks, chin, and chest. Forefeet have three functional toes. Hindfeet are long and strong, second to fourth digits long with long sharp claws,first and fifth digits shorter, reaching bases of central digits. Tail is long (92% of head-body length) and bicolored, dark with blackish bristles above, paler with whitish or yellowish bristles below. Females have 2+2 = 4 pairs of nipples. Karyotype 2n = 42,

Habitat. Moist,tall grasslands in savanna—forest mosaic, as well as montane grasslands to 2300 m elevation.

Food and Feeding. Diet comprises grass leaves and stems, herbs, and, in a cultivated area, green beans. Very large cecum and colon (comprising 60% of alimentary canal) are indicative of a diet of grasses.

Breeding. In Uganda, Dybowski’s Three-toed Grass Rats reproduce throughout year. Pregnant females have 2-6 embryos.

Activity patterns. Dybowski’s Three-toed Grass Rats is terrestrial and mostly diurnal. This species is unable to recolonize newly burnt grasses and is therefore not “fireadapted.”

Movements, Home range and Social organization. Dybowski’s Three-toed Grass Rat does not occupy burrows, but instead makes nests on surface of ground.

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

Bibliography. Delany (1975), Cheeseman & Delany (1979), Gautun et al. (1986), Happold (2013a), Matthey (1970), Monadjem et al. (2015).