Rhinolophus rhodesiae, Roberts, 1946

Burgin, Connor, 2019, Rhinolophidae, Handbook of the Mammals of the World – Volume 9 Bats, Barcelona: Lynx Edicions, pp. 280-332 : 285-286

11 . Roberts’s Horseshoe Bat

Rhinolophus rhodesiae

French: Rhinolophe de Rhodésie / German: Roberts-Hufeisennase / Spanish: Herradura de Rodesia

Taxonomy. Rhinolophus swinnyi rhodesiae Roberts, 1946 ,

“ Bezwe River, tributary of Wanetsi [= Nwanetsi] River , Southern Rhodesia [= Zimbabwe ]. ”

Rhinolophus rhodesiae is often included in R swinnyi , but recent genetic and morphometric analysis has determined that it is a distinct species. Rhinolophus rhodesiae is in the capensis species group and seems to be closely related to R simulator , R gorongosae , and one specimen of R landeri from Liberia. There is considerable genetic and echolocation variation throughout its distribution. Monotypic.

Distribution. E & S Africa in E Tanzania (including Unguja I in Zanzibar Archipelago), SW & SE DR Congo, Zambia, Malawi, Mozambique, Zimbabwe, and E South Africa (N Limpopo and S KwaZulu-Natal provinces); possibly also Swaziland, but these records have yet to be confirmed and might represent Swinny’s Horseshoe Bat ( A swinnyi ).

Descriptive notes. Head—body c. 44-65 mm, tail 16—30 mm, ear 15—20 mm, hindfoot 8 9 mm, forearm 40-44 mm; weight 4-5-8- 3 g. Roberts’s Horseshoe Bat is externally very similar to Swinny’s Horseshoe Bat. Pelage of Roberts’s Horseshoe Bat is soft and fluffy, being pale gray to pale brown dorsally (hairs with pale cream bases) and paler ventrally, occasionally being off-white or cream. Dorsal pelage can also be bright orange in orange morph. Males lack axillary tufts. Ears are short (33—36% offorearm length). Noseleafhas subtriangular lancet, with concave sides and bluntly pointed tip; connecting process is rounded; sella is naked, with slightly concave sides; narial lobes at base of sella are comparatively low; and horseshoe is narrow (width 6-2-8- 1 mm) and does not cover entire muzzle, does not have any lateral leaflets, and has deeply notched median emargination. Roberts’s Horseshoe Bat can be differentiated from Swinny’s Horseshoe Bat by its less concave hastate lancet and less erect and low rounded connecting process. Lower lip has three grooves, with lateral grooves being occasionally indistinct. Wings and uropatagium are brown. Roberts’s Horseshoe Bat has distinctly longer and tapered baculum than Swinny’s Horseshoe Bat, with conspicuously broader base and shallow notch along lower part of shaft that is visible in lateral view. Skull is delicately built, with thin zygomatic arches; nasal swellings are rounded; frontal depression is very shallow and sometimes nearly flat; supraorbital ridges are weak; and sagittal crest is absent posteriorly and very low anteriorly, being weakly developed. P2 is small but in tooth row, C1 and P4 are well separated as a result, and P is tiny and completely displaced labially, allowing P2 and P4 to touch or nearly touch one another.

Habitat Primarily savanna woodlands in lowland regions and montane and submontane rainforests at higher elevations. Roberts’s Horseshoe Bat is found at c. 1350 m in the Udzungwa Mountains, Tanzania, and c. 1642 m on Ntchisi Mountain in Malawi, where it can also be found in the adjacent open canopy miombo woodlands ofNtchisi Forest Reserve.

Food and Feeding. Roberts’s Horseshoe Bat probably forages by slow hawking and possibly gleaning. During wet season in Zambia, stomach samples of 23 bats had moths (55% of volume), beetles (26%), termites (6%), and various other insects, including flies, midges, crickets, and bugs. During dry season, stomach samples of nine bats included moths (56%), midges (43%), and flies (1%).

Breeding. Lactating and heavily pregnant Roberts’s Horseshoe Bats were recorded in early November (wet season) in Malawi, and a female had a single embryo in November in central Zimbabwe. Litter size is one.

Activity patterns. Roberts’s Horseshoe Bats are nocturnal. Day roosts are found primarily in caves and old mine shafts where they hang from ceilings. Call shape is FM/ CF/FM, and peak F component is 99—102 kHz in Malashane Cave, Mozambique, 102 — 104 kHz in Malawi (call durations of 37 - 74 milliseconds), 100 kHz in Soutpansberg, South Africa, and 107 — 112 kHz in Zimbabwe, although the record from Zimbabwe might not represent Roberts’s Horseshoe Bat because it is so different from typical frequencies recorded in other regions.

Movements, Home range and Social organization. Roosts of Roberts’s Horseshoe Bats have been found with 1- 5 individuals, roosting alone or in pairs. Some roosts have been recorded with over 100 individuals in south-western Zambia, southern DR Congo (Katanga), and Unguja Island. They have been recorded roosting with the Bushveld Horseshoe Bat ( R. simulator ) in Zimbabwe.

Status and Conservation. Not assessed on The IUCN ed List. Habitat loss seems to be the largest threat to Roberts’s Horseshoe Bat, although it is widespread and relatively common throughout its distribution.

Bibliography. ACR (2018), Ansell (1967, 1969), Cotterill (1996a, 2013e), Csorba et al. (2003), enton & Bell (1981), Mutumi et al. (2016), Taylor, Macdonald et al. (2018), Whitaker & Black (1976).

Figures

On following pages: 4. Lander's Horseshoe Bat (Rhinolophus landeri); 5. Guinean Horseshoe Bat (Rhinolophus guineensis); 6. Blasius's Horseshoe Bat (Rhinolophus blasii); 7. Peters's Horseshoe Bat (Rhinolophus lobatus); 8. Swinny's Horseshoe Bat (Rhinolophus swinnyi); 9. Cape Horseshoe Bat (Rhinolophus capensis); 10. Gorongosa Horseshoe Bat (Rhinolophus gorongosae); 11. Roberts's Horseshoe Bat (Rhinolophus rhodesiae); 12. Bushveld Horseshoe Bat (Rhinolophus simulato/); 13. Dent's Horseshoe Bat (Rhinolophus denti); 14. Cameroon Horseshoe Bat (Rhinolophus alticolus); 15. Mehely's Horseshoe Bat (Rhinolophus mehelyi); 16. Mediterranean Horseshoe Bat (Rhinolophus euryale); 17. Hildebrandt's Horseshoe Bat (Rhinolophus hildebrandtii); 18. Mount Mabu Horseshoe Bat (Rhinolophus mabuensis); 19. Cohen's Horseshoe Bat (Rhinolophus cohenae); 20. Smithers's Horseshoe Bat (Rhinolophus smithersi); 21. Mozambican Horseshoe Bat (Rhinolophus mossambicus); 22. Rüppell's Horseshoe Bat (Rhinolophus fumigatus); 23. Eloquent Horseshoe Bat (Rhinolophus Bloquons).

Distribution. E & S Africa in E Tanzania (including Unguja I in Zanzibar Archipelago), SW & SE DR Congo , Zambia , Malawi , Mozambique , Zimbabwe , and E South Africa (N Limpopo and S KwaZulu-Natal provinces); possibly also Swaziland , but these records have yet to be confirmed and might represent Swinny’s Horseshoe Bat ( A swinnyi ).