Elephantulus brachyrhynchus (A. Smith, 1836)

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 : 232

14.

Short-snouted Sengi

Elephantulus brachyrhynchus

French: Sengi a nez court / German: Kurznasen-Elefantenspitzmaus / Spanish: Sengi de hocico corto

Other common names: Short-snouted Elephant-shrew

Taxonomy. Macroscelides brachyrynchus [sic] A. Smith, 1836 , “country between [Lake] Latakoo [Kuruman, Northern Cape Province, South Africa] and the Tropic [of Capricorn, southern Botswana].”

This species is monotypic.

Distribution. Uganda, Kenya, Tanzania, S DR Congo, Angola, Zambia, Malawi, NE Namibia, N & E Botswana, Zimbabwe, S Mozambique, NE South Africa, and N Swaziland.

Descriptive notes. Head—body 99-127 mm, tail 95-108 mm, ear 20-22 mm, hindfoot 29-33 mm; weight 31-46 g. There is no evidence of sexual dimorphism in body size. Tail of the Short-snouted Sengi is ¢.90% of head—body length. Pinnae are broad and upright. Snoutis thin and flexible but short compared with other species of sengis. Dorsum is red-brown to yellow-brown, with c. 10mm hairs; scattered dorsal hairs are slightly longer and have black tips. This is the most widely distributed sengi species, and there is considerable clinal variation in dorsal pelage color: gray in East Africa, rufous-gray in Zambia, pale buff-gray or rufous-yellow in Namibia and Botswana, and dark gray-brown in Malawi. Ventral hairs have gray bases and white tips. Behind each ear, patch of buff hair usually extends onto nape of neck. Hair on all limbs is gray-white to off-white and resembles the venter. Distinctive white eye-ring is present, without intruding post-ocular patch. Sparse hair covers tail, darker above than below. There is no tail tuft. Skin of plantar pes is brown and hairless. 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 formula is I 3/3, C 1/1, P 4/4, M 2/3 (x2) = 42. Third lower molar is present in only three extant species: the Shortsnouted Sengi, the Dusky Sengi ( E. fuscus ), and the Dusky-footed Sengi (FE. fuscipes )—the basis for their previous assignment to the now defunct genus Nasilio. Canine sizes are subequal to adjacent teeth. Several bilateral pairs of palatal foramina are present. Postorbital processes are absent. Karyotype is 2n = 26.

Habitat. Mesic savanna and riparian habitats with woodlands and bushlands providing thick cover and abundant long grasses and shrubs. Shortsnouted Sengis sometimes inhabit fallow agricultural lands. Substrates are compact sandy grounds but not rocks. Thickets, dense grasses, and perhaps abandoned rodent burrows are used for sheltering.

Food and Feeding. Insects, predominantly ants and termites, are the principal diet of the Short-snouted Sengi. Other small invertebrates are also eaten. One study in Zimbabwe found that leaves and seeds made up only ¢.2% of diet by volume.

Breeding. The Short-snouted Sengi is monogamous, and pairs mate for life. In Zimbabwe, births occur year-round, but reproduction can be seasonal in other areas. Litter frequencies can be reduced in cooler months when insects are less abundant. Interbirth interval is ¢.60 days in warmer months and ¢.90 days in cooler months. Females can produce up to 23 ova per ovary per cycle, but limited uterus implantation sites constrain litter size. Embryo counts indicate that litters have 1-2 young. At parturition, newborns are highly precocial, with open eyes and almost

immediate ability to run. Direct paternal investment is absent from all species of sengis that have been studied. No species of soft-furred sengis use nests to shelter or for rearing their young.

Activity patterns. Short-snouted 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. Home ranges of monogamous pairs overlap, but combined area does not overlap home ranges of neighboring pairs. Males and females engage aggressive territorial behavior. At the Mankwe Wildlife Reserve, South Africa, one study found that, on average, males use c.0-41 ha and females use c.0-25 ha. Monogamous mating system is probably a mate-guarding strategy.

Status and Conservation. Classified as Least Concern on The IUCN Red List. The Shortsnouted Sengi is widespread, but its population trend is unknown.

Bibliography. Corbet & Hanks (1968), Evans (1942), Faurie (1996), Faurie et al. (1996), Hill (1938), Leirs et al. (1995), Neal (1984, 1995), Olbricht & Stanley (2009), Perrin (2013a), Rathbun (1979b, 2009, 2015c), Rautenbach & Schlitter (1977), Tripp (1971), Yarnell et al. (2008).

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. Uganda, Kenya, Tanzania, S DR Congo, Angola, Zambia, Malawi, NE Namibia, N & E Botswana, Zimbabwe, S Mozambique, NE South Africa, and N Swaziland.