498. Xeric Fourstriped Grass Rat Rhabdomys pumalio

French: Rhabdomys cotier / German: Eigentliche Vierstreifengrasmaus / Spanish: Rata de hierba de cuatro listas xérico Other common names: Fourstriped Field Mouse, Fourstriped Grass Mouse, Fourstriped Grass Rat, Xeric Four-striped Rhabdomys

Taxonomy. Mus pumilio Sparrman, 1784,

Slangrivier, Tsitsikamma Forest, east of Knys-na, Western Cape Province, South Africa.

Rhabdomys pumilio previously included R. bechuanae, R. chakae, R. dilectus, and R. intermedius as subspecies or variants, but molecular analyses indicated that treatment as five separate species is more appropriate. Monotypic.

Distribution. Restricted to a narrow coastal strip of W & S South Africa from mouth of the Orange River in NW Northern Cape to Port Elizabeth in S Eastern Cape province.

Descriptive notes. Head-body 93-134 mm, tail 99-128 mm, ear 13-16 mm, hindfoot 22-28 mm; weight 24-54 g. This small rodent with longitudinal black and cream stripes is similar morphologically to other Rhabdomys species, but background color is paler. Fur is coarse, yellowish brown to speckled buff above, paler below. It has no mid-dorsal stripe, but two lateral cream-colored broad stripes, each bordered by two black stripes, extend from between ears to base oftail. Head is of same coloras back, with black median stripe from between ears to between eyes. Nose, chin, throat, and abdomen are paler than dorsum. Ears are densely covered with short reddishbrown hairs. Forefeet are paler than dorsal fur, soles darkly pigmented. Tail is comparatively long (c.100% of head-body length), sparsely haired, bicolored, black above and yellowish brown or gray below. Females have 2+2 = 4 pairs of nipples.

Habitat. As distribution coincides largely with Fynbos biome, the Xeric Fourstriped Grass Ratis associated mostly with Mediterranean-climate shrublands and heathlands from the coast inland to mountains of Cape Fold Belt.

Food and Feeding. In the Western Cape observed to feed on succulent basal portions of bracts and styles of Proteaceae bushes. These grass rats may thus play an important role in pollination of these plants, as is known for Australian Proteaceae .

Breeding. In Western Cape, young are born in summer months. Femalesreach sexual maturity at 6-7 weeks and males at eleven weeks. Pregnant females have 2-9 embryos, and females have 1-4 (average two) litters per season.

Activity patterns. Diurnal and crepuscular. Terrestrial. A Xeric Fourstriped Grass Rat was observed to emerge from nest between 06:00 h and 07:00 h in morning and withdraw inside nest at 18:00-19:00 h where the species lives in family groups. The animals spend time in foraging and patrolling, but rest inthe bush or in nest during hottest period of day (11:00-15:00 h). Females forage more than males do, and latter spend time in patrolling at border of their home ranges.

Movements, Home range and Social organization. Xeric Foursstriped Grass Rats make burrows with well-concealed entrances. Females traveled on average 918 + 400 m/day (507-1498 m) and males moved on average 933 + 440 m/day (276-1618 m). There were no differences in home range size between males and females of the same group. In studies of wild colonies of Xeric Fourstriped Grass Rats in South Africa, C. Schradin and N. Pillay in 2004 found mean home range size of 990 m? for males and 960 m? for females, with nearly total overlap for members of the same family group. Longevity in the wild on the Cape Flats was 1-5 months, although in captivity these grass rats can live up to 24 months.

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

Bibliography. Brooks (1974), Castiglia et al. (2012), Du Toit et al. (2012), David & Jarvis (1985), Happold (2013a), Henschel et al. (1982), Monadjem et al. (2015), Rambau et al. (2003), Schradin & Pillay (2004), Skinner & Chimimba (2005).