Rhinolophus ruwenzorii, Hill, 1942

Burgin, Connor, 2019, Rhinolophidae, Handbook of the Mammals of the World – Volume 9 Bats, Barcelona: Lynx Edicions, pp. 280-332 : 300

40 . Ruwenzori Horseshoe Bat

Rhinolophus ruwenzorii

French: Rhinolophe du Rwenzori / German: Ruwenzori-Hufeisennase / Spanish: Herradura de Rwenzori

Taxonomy. Rhinolophus ruwenzorii Hill, 1942 ,

“ south side of Butahu Valley, western slope of Mount Ruwenzori [ DR Congo], altitude 7,500 feet [= 2286 m].”

Rhinolophus ruwenzorii is in the maclaudi species group. It has been considered a subspecies of R hilli , but morphometric data clearly demonstrate their distinction as separate species. Monotypic.

Distribution. Endemic to Ruwenzori Mts (NE DR Congo and SW Uganda), Ituri Forest and Kivu (NE DR Congo), Bwindi-Impenetrable Forest National Park (SW Uganda), and Mutura district (NW Rwanda).

Descriptive notes. Head-body 52-72 mm, tail 25-35 mm, ear 32-40 mm, hindfoot 11-7—14- 5 mm, forearm 55-61- 7 mm; weight 16-19- 5 g. Dorsal pelage is medium to dark smoky brown; venter is paler. There is no reported orange morph. Males lack axillary tufts. Ears are medium-long in length (57-66% of forearm length), with eight internal folds and very large antitragus. Noseleaf has subtriangular lancet, with bluntly pointed tip, and is taller than height of sella; connecting process is very reduced, low, and concave, leaving large depression between sella and lancet; sella is naked, upright, and about parallel to lancet, with concave sides and distinctly broadened and rounded spoon-shaped top; narial lobes at base of sella are very enlarged, nearly forming circular cup; nostrils are bordered by semicircular raised rims that are parallel to inner cup; and horseshoe is of medium width at 10-8—12- 6 mm, with lateral leaflets and conspicuous median emargination. Lower lip has conspicuous medial groove and two poorly developed lateral grooves that are occasionally lacking. Wings and uropatagium are dark gray. Skull is large but slender with weak zygomatic arches (zygomatic width is less than mastoid width); nasal swellings are high, with roughly circular chambers when viewed dorsally; frontal depression is very deep; sagittal crest is moderately developed anteriorly and poorly developed posteriorly, and interpterygoid groove is very deep. P2 is small and in tooth row or slightly displaced labially, separating C1 and P4; P3 is small and slightly to completely displaced labially; and distance between P2 and P4 is variable.

Habitat. Primarily submontane forests and marginally into lowland rainforests at elevations of 1066-2667 m. The Ruwenzori Horseshoe Bat is typically found in regions with montane evergreen/bamboo forests.

Food and Feeding. Stomach samples of five Ruwenzori Horseshoe Bats contained large moths, including their chewed-up wings and legs suggesting they eat prey whole without taking off any body parts.

Breeding. Four female Ruwenzori Horseshoe Bats that had recently stopped lactating were captured in late March along with two large juveniles. This indicated that some births occurred in early to mid-February.

Activity patterns. Ruwenzori Horseshoe Bats are nocturnal. Day roosts are found in caves and abandoned mine shafts.

Movements, Home range and Social organization. Ruwenzori Horseshoe Bats roost singly or in small groups of up to ten individuals. They have been recorded sharing day roosts with Long-haired Fruit Bats ( Stenonycteris lanosus ), Geoffrey's Horseshoe Bats ( clivosus ), and Sundevall’s Leaf-nosed Bats (Hipposideros caffer) or Noack’s Leafnosed Bats, (H. ruber).

Status and Conservation. Classified as Vulnerable on The IUCN ed List. The Ruwenzori Horseshoe Bat is threatened by habitat loss and degradation and possibly overharvesting for bushmeat.

Bibliography. ACR (2018), Baeten et al. (1984), Csorba et al. (2003), Fahr (2008b, 2013h), Fahr et al. (2002), Hayman et al. (1966), Kerbis Peterhans et al. (2013), Smith & Hood (1980).

Figures

On following pages: 27. African Forest Horseshoe Bat (Rhinolophus silvestris); 28. Upland Horseshoe Bat (Rhinolophus hillorum); 29. Sakeji Horseshoe Bat (Rhinolophus sakejiensis); 30. Bokhara Horseshoe Bat (Rhinolophus bocharicus); 31. Greater Horseshoe Bat (Rhinolophus ferrumequinum); 32. Geoffrey's Horseshoe Bat (Rhinolophus clivosus); 33. Greater Japanese Horseshoe Bat (Rhinolophus nippon); 34. Horacek's Horseshoe Bat (Rhinolophus horaceki); 35. Maclaud's Horseshoe Bat (Rhinolophus maclaudi); 36. Ziama Horseshoe Bat (Rhinolophus ziama); 37. Hill's Horseshoe Bat (Rhinolophus hilli); 38. Kahuzi Horseshoe Bat (Rhinolophus kahuzi); 39. Willard's Horseshoe Bat (Rhinolophus willardi); 40. Ruwenzori Horseshoe Bat (Rhinolophus ruwenzorii); 41. Chinese Horseshoe Bat (Rhinolophus xinanzhongguoensis); 42. Big-eared Horseshoe Bat (Rhinolophus macrotis); 43. Osgood's Horseshoe Bat (Rhinolophus osgoodi); 44. Allen's Horseshoe Bat (Rhinolophus episcopus); 45. Thai Horseshoe Bat (Rhinolophus siamensis); 46, Schnitzler's Horseshoe Bat (Rhinolophus schnitzten); M. King Horseshoe Bat (Rhinolophus rex); 48. Marshall’s Horseshoe Bat (Rhinolophus marshalli).

Distribution. Endemic to Ruwenzori Mts (NE DR Congo and SW Uganda ), Ituri Forest and Kivu (NE DR Congo ), Bwindi-Impenetrable Forest National Park (SW Uganda ), and Mutura district (NW Rwanda ).