Rhynchocyon stuhlmanni (Matschie, 1893)

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 : 227-228

3.

White-tailed Sengi

Rhynchocyon stuhlmanni

French: Sengi de Stuhlmann / German: Dunkles Risselhindchen / Spanish: Sengi de cola blanca

Other common names: White-tailed Elephant-shrew, Stuhlmann’s Elephant-shrew, Stuhlmann’s Sengi

Taxonomy. Rhynchocyon cirner stuhlmanni Matschie, 1893 ,

Andunde (Bundundi) Semliki River , west of Ruwenzori , Congo Belge (about 0°40’N 29°40’E, near the Semliki River, North-Kivu Province, DR Congo).

Rhynchocyon stuhlmanni was formerly a subspecies of R. cirnei but elevated to full species by E. J. Carlen and others in 2017. Monotypic.

Distribution. N DR Congo and Uganda;

perhaps near Bangui, S Central African Republic.

Descriptive notes. Head-body 242-303 mm, tail 220-265 mm, ear 29-34 mm, hindfoot 81-91 mm. No specific data are available for body weight. Tail of the Whitetailed Sengi is ¢.90% of head-body length and is proximally thick and distally

tapered. Pelage color patterns are similar to the Chequered Sengi ( R. cirnei ), including checkered appearance of rump and back, but tail of the White-tailed Sengi is white from near base to tip. There is clinial color variation in the dorsal pelage: yellow-brown in western distribution of DR Congo, dark black-brown in eastern distribution of DR Congo, and gray-brown in Uganda. Compared with the Chequered Sengi, nasal bones are relatively short, with extension posterior to maxillae less than 13% of condylo-basal length. Relatively short nasals and all-white tail are diagnostic for the White-tailed Sengi. Snout is long and flexible. Females have two posterior, two intermediate, and no anterior 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. Dental formula is 1 0-1/3, C 1/1, P 4/4, M 2/2 (x2) = 34-36. Upper canines are relatively large. Presence of diminutive upper incisor is variable. Palatal foramina are absent. Postorbital processes are present. Karyotype is unknown.

Habitat. Forests of the Congo River Basin (closed canopies and dense leaflitter always present). Distribution of the White-tailed Sengi is disjunct from all other species of Rhynchocyon .

Food and Feeding. Diet of the White-tailed Sengiis strictly composed of invertebrates, mostly arthropods.

Breeding. There is no information available for this species, but based on other species of Rhynchocyon , the White-tailed Sengi is probably monogamous and breeds yearround. Litters probably have 1-2 young.

Activity patterns. White-tailed Sengis are fully terrestrial and exclusively diurnal. Forest-floor nests are built from leaflitter.

Movements, Home range and Social organization. The White-tailed Sengi is presumably similar to the Golden-rumped Sengi ( R. chrysopygus ). Each member of a male—female pair probably spends most of its time independently.

Status and Conservation. Not assessed on The IUCN Red List. Before being elevated to full species rank in 2017, the White-tailed Sengi was considered a Chequered Sengi, which is classified as Least Concern.

Bibliography. Allen (1922), Carlen et al. (2017), Corbet & Hanks (1968), Evans (1942), Olbricht & Stanley (2009), Rathbun (2009, 2013e).

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. N DR Congo and Uganda; perhaps near Bangui, S Central African Republic.