Cricetomys ansorgei, Thomas, 1904

Don E. Wilson, Russell A. Mittermeier & Thomas E. Lacher, Jr, 2017, Nesomyidae, Handbook of the Mammals of the World – Volume 7 Rodents II, Barcelona: Lynx Edicions, pp. 156-203 : 196

39.

Southern Giant Pouched Rat

Cricetomys ansorgei

French: Cricétome d’Ansorge / German: Sidliche Riesenhamsterratte / Spanish: Rata de abazones gigante meridional

Taxonomy. Cricetomys ansorgei Thomas, 1904 ,

Pungo Andongo , Angola.

Taxonomy of C. ansorgei is currently unclear, and it might represent a species complex. Recent molecular studies of Cricetomys have not fully aligned with morphological studies, suggesting that traditional morphological traits may not be useful in distinguishing species in this genus. Six subspecies recognized.

Subspecies and Distribution.

C. a. ansorgei Thomas, 1904 — from DR Congo S of the Congo River extending E to Kenya, and S to Angola, Zambia, Tanzania, Malawi, Zimbabwe, Mozambique, and extreme NE South Africa.

a. cosenst Hinton, 1919 — Zanzibar, Tanzania. a. elgonis Thomas, 1910 — Mt Elgon, Uganda—Kenya. DoDD a. enguvi Heller, 1912 — Taita Hills, Kenya.

a. kenyensis Osgood, 1910 — Mt Kenya.. a. microtis Lonnberg, 1917 — Virunga Mts, DR Congo.

Descriptive notes. Head-body 288-413 mm, tail 345-449 mm, ear 32-42 mm, hindfoot 68-78 mm; weight 1.2-8 kg (males) and 0.9-1.4 kg (females). The Southern Giant Pouched Ratis the largest muroid rat within its distribution and has well-developed cheek pouches. Fur is long and harsh to the touch, brown or grayish brown dorsally, shading to white or cream ventrally. Snout is long and pointed, with dark rings around eyes. Ears are relatively long. Tailis slightly longer than head-body length, with terminal one-half conspicuously white compared with dark proximal one-half. Limbs are relatively short, with four digits on forefeet and five digits on hindfeet.

Habitat. Wide range of savanna, woodlands, and forests. The Southern Giant Pouched Rat is often commensal with humans,living at high densities in some urban and periurban environments. It excavates burrows, primarily with its teeth, typically at bases of large trees or boulders.

Food and Feeding. The Southern Giant Pouched Rat mostly eats fruits, seeds, and tubers that might be cached in a burrow. Gut morphology is complex, and passage rates are slow, adaptations to exploit nutrient-poor foods. Coprophagy appears to pass on gut microbes from mother to offspring to assist with digestion.

Breeding. Pregnant Southern Giant Pouched Rats have mostly been recorded during the rainy season in September—May. Averagelittersize is three young for the closely related Northern Giant Pouched Rat ( C. gambianus ). Gestation is 27-42 days. Growth is rapid, with sexual maturity at c.20 weeks for the closely related Northern Giant Pouched Rat. Southern Giant Pouched Rats can survive c.8 years in captivity.

Activity patterns. The Southern Giant Pouched Rat is nocturnal, with two peaks in activity and a lull between 22:00 h and 01:00 h. Most of the night is spent in a burrow, and only one-quarter of the night spent outside. It is terrestrial but might also climb.

Movements, Home range and Social organization. The Southern Giant Pouched Rat is typically solitary, with one individual occupying a burrow system. Average home range was 4-9 ha, with males wandering over larger areas than females. Densities might be high in prime habitat; 42 individuals were captured on a 0-5ha garden in Harare, Zimbabwe.

Status and Conservation. Not assessed on The IUCN Red List. The Southern Giant Pouched Rat causes damage to crops and orchards and is often persecuted. It is hunted for food over much ofits distribution. Despite these pressures, it does not appear to have suffered from a range contraction or reduced population. Due to its acute sense of smell and high level of intelligence,it has been trained to detect land mines.

Bibliography. Ajayi (1975), Ansell & Dowsett (1988), Ewer (1967), Genest-Villard (1967), Knight (1984), Knight & Knight-Eloff (1987), Monadjem et al. (2015), Morris (1963), Olayemi et al. (2012), Perrin & Kokkinn (1986), Poling et al. (2010), Ray & Duplantier (2013), Skinner & Chimimba (2005), Smithers &Tello (1976), Smithers & Wilson (1979).

Figures

1. White-tailed Tree Rat (Brachytarsomys albicauda), 2. Hairy-tailed Tree Rat (Brachytarsomys villosus), 3. Sleek-furred Ground Rat (Gymnuromys robert), 4. Antsingy Tufted-tail Rat (Eliurus antsingy), 5. Carleton’s Tufted-tail Rat (Eliurus carletoni), 6. Daniel’s Tufted-tail Rat (Elurus daniels), 7. Ellerman’s Tufted-tail Rat (Eliurus ellermani), 8. Grandidier’s Tufted-tail Rat (Eliurus grandidieri), 9. Major's Tufted-tail Rat (Eliurus majori), 10. Lesser Tufted-taill Rat (Elurus minor), 11. Milne-Edwards’s Tufted-tail Rat (Eliurus myoxinus), 12. White-tailed Tufted-tail Rat (Eliurus penicillatus), 13. Petter’s Tufted-tail Rat (Eliurus petteri), 14. Tanala Tufted-taill Rat (Elwurus tanala), 15. Webb's Tufted-tail Rat (Eliurus webbi), 16. Anjozorobe Naked-tail Forest Mouse (Voalavo antsahabensis), 17. Northern Naked-tail Forest Mouse (Voalavo gymnocaudus), 18. Bastard’s Big-footed Mouse (Macrotarsomys bastardi), 19. Ankarafantsika Big-footed Mouse (Macrotarsomys ingens), 20. Petter’s Big-footed Mouse (Macrotarsomys peter), 21. Koopman' ’ s Forest Mouse (Monticolomys koopmani), 22. Giant Jumping Rat (Hypogeomys antimena), 23. Small Short-tailed Rat (Brachywromys betsileoensis), 24. Large Short-tailed Rat (Brachyuromys ramirohitra), 25. Audebert’s Forest Rat (Nesomys audeberti), 26. Lamberton’s Forest Rat (Nesomys lambertoni), 27. Red Forest Rat (Nesomys rufus), 28. Delany’s Swamp Mouse (Delanymys brooksi), 29. African White-tailed Rat (Mystromys albicaudatus), 30. Shortridge’s Pygmy Rock Mouse (Petromyscus shortridger), 31. Short-eared Pygmy Rock Mouse (Petromyscus monticularis), 32. Barbour’s Pygmy Rock Mouse (Petromyscus barbouri), 33. Common Pygmy Rock Mouse (Petromyscus collinus)

Subspecies and Distribution. C. a. ansorgei Thomas, 1904 — from DR Congo S of the Congo River extending E to Kenya, and S to Angola, Zambia, Tanzania, Malawi, Zimbabwe, Mozambique, and extreme NE South Africa. a. cosenst Hinton, 1919 — Zanzibar, Tanzania. a. elgonis Thomas, 1910 — Mt Elgon, Uganda—Kenya. DoDD a. enguvi Heller, 1912 — Taita Hills, Kenya. a. kenyensis Osgood, 1910 — Mt Kenya.. a. microtis Lonnberg, 1917 — Virunga Mts, DR Congo.