Rhynchocyon udzungwensis, Rathbun & Rovero, 2008

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 : 228

5.

Gray-faced Sengi

Rhynchocyon udzungwensis

French: Sengi a face grise / German: Graugesicht-Risselhlindchen / Spanish: Sengi de cara gris

Other common names: Gray-faced Elephant-shrew, Grey-faced Sengi, Grey-faced Elephant-shrew

Taxonomy. Rhynchocyon udzungwensis Rathbun & Rovero, 2008 ,

“ Vikongwa River Valley , Ndundulu Forest , West Kilombero Scarp Forest Reserve , Udzungwa Mountains , Iringa Region, Tanzania [7°48.269’S, 36°30.355’E (Arc 1960 datum) |, at 1350 m a.s.l.”

This species is monotypic.

Distribution. Udzungwa Mts of Eastern Arc Mts, C Tanzania.

Descriptive notes. Head-body 297-318 mm, tail 239-262 mm, ear wy mm, hindfoot 79-88 mm; weight 658-750 g. There is no evidence of sexual dimorphism in body size. Tail of the Gray-faced Sengi is ¢.80% of head-body length and is proximally thick and distally tapered. Tail skin is black on dorsal side and dark brown below, with subterminal white, 4-6cm band; tail hair is short, sparse, and same color as skin. Pinnae are nearly hairless, with black to dark brown skin. Hairs on top and sides of face have black bases and cream or white tips giving face a gray appearance, which is diagnostic. Hair behind ears and on shoulders is rufous-yellow, transitions to rufous on dorsum and orange-rufous on sides and becomes black near rump. Hair on venter is pale yellow to cream. Skin on snoutis black and nearly hairless. Snout is exceptionally long and flexible. Dental formulais10-1/3,C1/1,P 4/4, M 2/2 (x2) = 34-36. Upper canines are relatively large, and males have longer upper canines than females. Although not yet reported, presence of diminutive upper incisor presumably is probably variable. Palatal foramina are absent. Postorbital processes are present. Females have two posterior, two intermediate, and no anterior nipples; males have no nipples. Four digits are present on each manus and pes; pollex and hallux are absent. Fifth manual digit is relatively short and has only two phalanges. Post-anal gland is well developed, and pectoral gland is absent. Karyotype is unknown.

Habitat. Montane forests (closed canopies and dense leaflitter always present) at elevations of 1000-2300 m. In the northern Mwanihana Forest, some Gray-faced Sengis occur in deciduous to semi-deciduous lowland habitat, which might be suboptimal.

Food and Feeding. Diet of the Gray-faced Sengi is probably strictly composed of invertebrates and mostly arthropods, based on similar habitats and shared biology with other species of Rhynchocyon .

Breeding. There is no information available for this species, but the Gray-faced Sengi is probably similar to the Black-and-rufous Sengi ( R. petersi ).

Activity patterns. Gray-faced Sengis are fully terrestrial and exclusively diurnal. Nesting is probably similar to that of other species of Rhynchocyon . Each member of a male—female pair probably spends most ofits time independently.

Movements, Home range and Social organization. There is no information available for this species, but the Gray-faced Sengi is probably similar to other species of Rhynchocyon .

Status and Conservation. Classified as Vulnerable on The IUCN Red List. The Grayfaced Sengi occurs only in Ndundulu-Luhomero and Mwanihana forests, which are prone to stochastic drought-driven and human-induced fires. Its area of occupancy is estimated to be only 390 km?, and its population trend is unknown.

Bibliography. Carlen et al. (2017), Corbet & Hanks (1968), Dollman (1912), Evans (1942), Lawson et al. (2013), Olbricht & Stanley (2009), Rathbun (2009, 2013c), Rovero & Rathbun (2015), Rovero 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. Udzungwa Mts of Eastern Arc Mts, C Tanzania.