Otomys jacksoni, Thomas, 1891

Don E. Wilson, Russell A. Mittermeier & Thomas E. Lacher, Jr, 2017, Muridae, Handbook of the Mammals of the World – Volume 7 Rodents II, Barcelona: Lynx Edicions, pp. 536-884 : 743

392.

Mount Elgon Vlei Rat

Otomys jacksoni

French: Otomys de Jackson / German: Mount-Elgon-Lamellenzahnratte / Spanish: Rata de laguna de Elgon

Taxonomy. Otomys jacksoni Thomas, 1891 ,

“Mount Elgon, 13200 ft [= 4023 m],” Uganda.

Although previously included in O. typus , O. jackson: differs from it in body size, number of M® lamina, and genetically. Monotypic. Distribution. Known only from Mt Elgon, E Uganda and W Kenya. Descriptive notes. Head-body 120-171 mm, tail 57-82 mm, ear 19-26 mm, hindfoot 19-26 mm; weight 70-121 g. The Mount Elgon Vlei Rat is medium to large in size and robust, with large blunt head,shorttail, and shaggy fur; it is the smallest of the O. typus species group. Fur coloris not clearly distinct from the Ethiopian Vlei Rat ( O. typus ). Lower incisors each have two deep grooves. M, has four laminae, and M? has seven laminae.

Habitat. Dense grasslands in alpine zone at elevations of 3300-4200 m. The Mount Elgon Vlei Rat avoids wet swampy areas occupied by co-occurring Barbour’s Vlei Rats (O. barbounri). Food and Feeding. Dominant food items of the Mount Elgon Vlei Rat are grasses such as Festuca pilgeri, Koeleria capensis , and Argostis gracilifolia (all Poaceae ) and flowers of Helichrysum (Asteraceae) . Breeding. Breeding of the Mount Elgon Vlei Rat is continuous, and reproductive individuals and juveniles can be found year-round. Activity patterns. The Mount Elgon Vlei Rat is presumably diurnal or crepuscular. Movements, Home range and Social organization. Mount Elgon Vlei Rats do not make nests. Home ranges overlap considerably and are 401-728 m® for males and 181-481 m” for females. Status and Conservation. Not assessed on The IUCN Red List. The Mount Elgon Vlei Rat has a restricted distribution and known negative anthropogenic impacts include uncontrolled fires resulting in habitat loss. Both conditions might justify classification as Endangered. Bibliography. Clausnitzer (2003), Monadjem et al. (2015), Taylor, Lavrenchenko et al. (2011), Taylor, Maree et al. (2014).

Figures

On following pages: 385. Yalden's Vlei Rat (Otomys yaldeni); 386. Burton's Vlei Rat (Otomys burton); 387. Western Vlei Rat (Otomys occidentalis); 388. Barbour’s Vlei Rat (Otomys barbouri); 389. Rwenzori Vlei Rat (Otomys dartmouthi): 390. Dent's Vlei Rat (Otomys denti); 391. Dolliman’s Vlei Rat (Otomys dollmani); 392. Mount Elgon Vlei Rat (Otomys jacksoni); 393. Afroalpine Vlei Rat (Otomys orestes); 394. Thomas's Vlei Rat (Otomys thomas); 395. EastAfrican Vlei Rat (Otomys tropicalis); 396. Tanzanian Vlei Rat (Otomys lacustris); 397. Eastern Arc Vlei Rat (Otomys sungae); 398. Udzungwa Vlei Rat (Otomys uzungwensis); 399. MountKilimanjaro Vlei Rat (Otomys zinki): 400. Angolan Vlei Rat (Otomys anchietae); 401. Cuanza Vlei Rat (Otomys cuanzensis); 402. Angoni Vlei Rat (Otomys angoniensis); 403. South East African Vlei Rat (Otomys auratus); 404. Southern African Vlei Rat (Otomys irroratus): 405. Fynbos Vlei Rat (Otomys karoensis); 406. KwaZulu Natal Vlei Rat (Otomys laminatus); 407. Sloggett's Vlei Rat (Otomys sloggett)); 408. Karoo Vlei Rat (Otomys unisulcatus); 409. Brants's Whistling Rat (Parotomys brantsii); 410. Littledale’s Whistling Rat (Parotomyslittledale).

Although previously included in O. typus , O. jackson: differs from it in body size, number of M® lamina, and genetically. Monotypic. Distribution. Known only from Mt Elgon, E Uganda and W Kenya. Descriptive notes. Head-body 120-171 mm, tail 57-82 mm, ear 19-26 mm, hindfoot 19-26 mm; weight 70-121 g. The Mount Elgon Vlei Rat is medium to large in size and robust, with large blunt head,shorttail, and shaggy fur; it is the smallest of the O. typus species group. Fur coloris not clearly distinct from the Ethiopian Vlei Rat ( O. typus ). Lower incisors each have two deep grooves. M, has four laminae, and M? has seven laminae.