Elephantulus edwardii (A. Smith, 1839)

Russell A. Mittermeier & Don E. Wilson, 2018, Macroscelididae, Handbook of the Mammals of the World – Volume 8 Insectivores, Sloths and Colugos, Barcelona: Lynx Edicions, pp. 206-234 : 234

19.

Cape Rock Sengi

Elephantulus edwardii

French: Sengi du Cap / German: Kap-Elefantenspitzmaus / Spanish: Sengi de roca de El Cabo

Other common names: Cape Elephant-shrew, Cape Rock Elephant-shrew, Cape Sengi

Taxonomy. Macroscelides edwardii A. Smith, 1839 ,

“ one of the central districts of the colony , near to the Oliphant’s river,” Western Cape Province, South Africa.

G. B. Corbet and J. Hanks in 1968 stated that Smith’stype locality could refer to the Oliphants River (= Olifantsrivier) in the Oudtshoorn district but more likely refers to the Oliphants River that originates in the Grootwinterhoek Wilderness Area and flows into the Atlantic near Papendorp— both in Western Cape Province. Monotypic.

Distribution. South Africa (Northern Cape, Western Cape, and Eastern Cape provinces).

Descriptive notes. Head—body 94-125 mm, tail 117-160 mm, ear 25-36 mm, hindfoot 31-36 mm; weight 37-83 g. Female Cape Rock Sengis can be slightly larger than males, but there is no substantial sexual dimorphism in body size. Tail is relatively long at c.125% of head-body length. Tail hairs are very short and black on dorsal side. On ventral side of tail, proximal hairs are paler, and distal hairs are black; longer hairs form small tail tuft near tip. Pinnae are broad and upright, and snout is long, thin, and flexible. Dorsum is gray to gray-brown, perhaps with tinge of yellow. Lateral pelage transitions into paler ash-gray. Venter is gray to gray-white. Hairs of dorsal head and face are similar in color to lateral pelage. Some hairs of dorsal body, flanks, and face have black tips, giving grizzled appearance. Inconspicuous patches of gray-brown to orange-brown hairs behind ears extend onto nape of neck and grade into graybrown dorsum. Long ash-gray hairs grow along anterior margin of each pinna. Pale gray-white eye-ring is present, without an intruding post-ocular patch. Females have two anterior, two intermediate, and two posterior nipples; males have no nipples. Five digits are present on each manus and pes. Pectoral gland is absent, and subcaudal gland is present. Dental formulais 13/3, C1/1,P 4/4, M 2/2 (x2) = 40. Canine sizes are subequal to adjacent teeth. Severalbilateral pairs of palatal foramina are present. Postorbital processes are absent. Karyotype is 2n = 26.

Habitat. Arid rocky substrates on mountains, small outcrops, and flat rock sills with minimal vegetative cover but sometimes adjacent to relatively flat compact sandy grounds with sparse dwarf shrubs. The Cape Rock Sengi shelters among boulders and in rock crevices.

Food and Feeding. Insects, mainly ants, are the principal diet of the Cape Rock Sengi. Other arthropod prey includes termites, beetles, roaches, and locusts. Small amounts of green plant material can also be eaten. Some observations have found that the Cape Rock Sengi acts as a pollination vector while foraging on insects near flowers ( Protea , Proteaceae ) and drinking nectar of bulbous perennials ( Whiteheadia , Asparagaceae ). Main foraging strategy has been described as “wait, dash, and snatch,” which is consistent with observations of many species of sengis. The Cape Rock Sengi has been observed turning over hyrax (Procavidae) dung piles to pursue underlying insects.

Breeding. The Cape Rock Sengi is probably monogamous. Births occur more frequently in September-February during the warm, wet seasons. Females can produce up to 55 ova per ovary per cycle, but limited uterus implantation sites constrain litter size. Litters usually have one young, sometimes two. At birth, young are ¢.10 g, highly precocial with eyes open, and fully mobile. There is no direct paternal care of young. No species of soft-furred sengis use nests to shelter or for rearing their young.

Activity patterns. Cape Rock Sengis are fully terrestrial. Activity is polycyclic with crepuscular peaks and some nocturnal tendencies. Midday activity is least frequent.

Movements, Home range and Social organization. The Cape Rock Sengi probably forms monogamous pairs where individuals interact infrequently. Male—female pairs are sometimes trapped together, suggesting some degree of overlap in their home

ranges. Lack of same-sex trappings might indicate territoriality or at least mutual avoidance. Home rangesizes of Cape Rock Sengis are probably comparable with those of the Eastern Rock Sengi ( E. myurus , less than 0-5 ha), given that both species are rupicolous and occur in comparable habitats.

Status and Conservation. Classified as Least Concern on The IUCN Red List. The Cape Rock Sengi is widespread in suitable habitat, but its population trend is unknown.

Bibliography. Corbet & Hanks (1968), Dempster et al. (1992), Evans (1942), Fleming & Nicolson (2002), Leon et al. (1983), Olbricht & Stanley (2009), Perrin & Rathbun (2013c), Rathbun (2009), Rathbun & Smit-Robinson (2015¢), Rautenbach & Schlitter (1977), Stuart et al. (2003), Tripp (1971), Wester (2010), Woodall et al. (1989).

Figures

1. Golden-rumped Seng (Rhynchocyon chrysopygus), 2. Chequered Sengi (Rhynchocyon cirne), 3. White-tailed Sengi (Rhynchocyon stuhlmanni), 4. Black-and-rufous Sengi (Rhynchocyon petersi), 5. Gray-faced Sengi (Rhynchocyon udzungwensis), 6. Namib Round-eared Sengi (Macroscelides flavicaudatus), 7. Karoo Round-eared Sengi (Macroscelides proboscideus), 8. Etendeka Round-eared Sengi (Macroscelides micus), 9. Four-toed Sengi (Petrodromus tetradactylus), 10. North African Sengi (Petrosaltator rozeti), 11. Rufous Sengi (Elephantulus rufescens), 12. Somali Sengi (Elephantulus revoulii), 13. Dusky-footed Sengi (Elephantulus fuscipes), 14. Short-snouted Sengi (Elephantulus brachyrhynchus), 15. Dusky Sengi (Elephantulus fuscus), 16. Bushveld Sengi (Elephantulus intufi), 17. Western Rock Sengi (Elephantulus rupestris), 18. Eastern Rock Sengi (Elephantulus mywrus), 19. Cape Rock Sengi (Elephantulus edwardii), 20. Karoo Rock Sengi (Elephantulus pilicaudus)

Distribution. South Africa (Northern Cape, Western Cape, and Eastern Cape provinces).