407.

Sloggett’s Vlei Rat

Otomys sloggetti

French: Otomys de Sloggett / German: Sloggett-Lamellenzahnratte / Spanish: Rata de laguna de Sloggett

Other common names: Ice Rat, Sloggett’s Rat

Taxonomy. Otomys sloggetti Thomas, 1902,

Deelfontein, Northern Cape, South Africa.

Although some authors place O. sloggetti and O. unisulcatus in the genus Myotomys, phylogenetic position of these primitive species remains elusive. Current morphological and genetic evidence does not support monophyly of Myotomys but rather existence of an “arid” clade with O. unisulcatus, O. sloggetti, and both species of Parotomys, separate from a “mesic”

clade with all other species Otomys, according to, most recently, M. A. Phukuntsi and colleagues in 2016. The study based on combined nDNA and mtDNA sequences by Phukuntsi and colleagues revealed an undescribed smaller species co-occurring in the same burrows as O.sloggetti at one locality in the Drakensberg Mountains, Eastern Cape Province. Although superficially resembling O. sloggetti, this undescribed species is distinctly smaller and darker brown, and it has distinct groove in lower incisors (absent in sloggetti), round petrotympanic foramen (slit-like in sloggetti), six laminae in M? (five in sloggetti), and rougher hair on tail (smoother in sloggetti). Monotypic.

Distribution. High Drakensberg in South Africa and Lesotho.

Descriptive notes. Head-body 93-170 mm, tail 47-84 mm, ear 14-22 mm, hindfoot 21-30 mm; weight 45-155 g. Sloggett’s Vlei Rat is large and robust, with large blunt head, shorttail, and shaggy fur. Fur is pale grayish buff above, grayish brown on flanks, and whitish buff below. Tail is short (c.49% of head-body length) and bicolored. Females have twopairs of nipples. Upper incisors each have single grooves, and lower incisors have a very faint groove. M has four laminae, and M? has 4-5 laminae. Chromosomal complement is 2n = 42 and FNa = 48.

Habitat. Montane and alpine grasslands in dry and wet soils, with and without rocky outcrops, at elevations of 1500 m to more than 2000 m.

Food and Feeding. Sloggett’s Vlei Rats eat stems, flowers, and leaves of various green plants. They forage close to burrow entrances. In summer, food is eaten immediately, but in winter, it is mostly hoarded in burrows.

Breeding. Reproduction occurs in midto late summer in Lesotho. Litters have 1-5 young. Gestation is 38 days.

Activity patterns. Sloggett’s Vlei Rats are diurnal and sun themselves on exposed rocks or at entrances oftheir burrows intermittently throughout the day.

Movements, Home range and Social organization. Burrows are occupied by pairs or family groups of 4-16 individuals. Underground, groups huddle to conserve heat and show noterritorial behavior, but aboveground, individuals of a group are partly territorial and defend parts of overlapping home ranges. Densities of 100 ind/ha have been recorded in rocky habitats.

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

Bibliography. Contrafatto et al. (1992), Happold (2013a), Hinze et al. (2006), Lynch (1994), Lynch & Watson (1992), Monadjem et al. (2015), Phukuntsi et al. (2016), Richter (1997), Richter et al. (1997), Schwaibold & Pillay (2003), Willan (1990).