Rhinolophus rex, G. M. Allen, 1923

Burgin, Connor, 2019, Rhinolophidae, Handbook of the Mammals of the World – Volume 9 Bats, Barcelona: Lynx Edicions, pp. 280-332 : 302

47 . King Horseshoe Bat

Rhinolophus rex

French: Rhinolophe roi I German: Königshufeisennase / Spanish: Herradura real

Other common names: Bourret's Horseshoe Bat (paradoxolophus)

Taxonomy. Rhinolophus rexG. M. Allen, 1923 ,

“ Wanhsien , Szechwan Province, China.”

Rhinolophus rex is in the macrotis species group and sister to the clade that includes the. macrotis complex and. siamensis . Rhinolophus paradoxolophus was generally recognized as a species distinct from. rex , but the two taxa are now considered a single species based on genetic data. Nevertheless, they are distinguishable based on size and call frequency, despitnot forming fully monophyletic groups. Additional morphometric studies are needed across the entire distributions of both taxa to clarify their taxonomic relationships. Two subspecies recognized.

Subspecies and Distribution.

. r. rex G. M. Allen, 1923 - S & SE China (Sichuan, Chongqing, Guizhou, Hunan, Guangxi, and Guangdong).

. r. paradoxolophus Bourret, 1951 — SE China (E Guangxi and probably E Yunnan), E Myanmar, N Thailand, N & C Laos, and N & C Vietnam.

Descriptive notes. Head-body 47-50 mm, tail 19- 6-38 mm, ear 26-39 mm, hindfoot 7-3—10- 1 mm, forearm 53-63 mm; weight 8-15 g. “Bourret’s Horseshoe Bat” (. r. paradoxolophus ) is primarily distinguished by its smaller skull and forearm size. Dorsal pelage is light cinnamon-buff or dark brown; venter is generally paler and more grayish. There is no orange morph. Males lack axillary tufts. Ears are extremely large, with well-developed antitragus. Noseleaf has very short subtriangular lancet, with broadly rounded tip, nearly concealed by fur ; connecting process is low, convex, and slopes from base of lancet to sella; sella is very long, wide, and tongue-shaped, its tip is broadly blunt and narrowest at base, and there is longitudinal median depression extending almost to top of sella; intemarial cup is very broad and extends laterally over much of horseshoe and covers nostrils; and horseshoe is very wide at 9-12- 5 mm, covers muzzle, and has no lateral leaflets and very deep median emargination. There are three medial grooves on lower lip. Skull is large, elongated, and narrow (zygomatic width is considerably smaller than mastoid width); median nasal swellings are prominent and elliptical, protruding anteriorly beyond rostral wall; lateral compartments are elongated; sagittal crest is very low; frontal depression is clearly well developed; and supraorbital crests are moderately developed. P2 is small and completely in tooth row, separating C 1 and P4; P3 is minute to small and in tooth row, varyingly separating or allowing P2 and P4 to touch. Chromosomal complement has 2n = 62 and FNa = 60.

Habitat. Mainly primary tropical lowland forests and often associated with limestone formations at elevations of 370-1329 m. King Horseshoe Bats seem to prefer moist forests, but individuals in Thailand were found in dry pine forests with Pinus merkusii (Pinaceae) and Shorea (Dipterocarpaceae) , and they were collected in limestone caves surrounded by secondary pine forest and sesame cultivar at 1320 m.

Food and Feeding. The King Horseshoe Bat apparently hunts flying insects around trees and bushes.

Breeding. Pregnant King Horseshoe Bats were captured in April, and lactating females were captured in May-July in Vietnam. Litter size is one.

Activity patterns. King Horseshoe Bats are nocturnal, forage throughout the night, and roost during the day. Individuals have been found in torpor during the day. They hibernate in winter in at least south-central China, although probably not in the southern part of the distribution. King Horseshoe Bats roost mainly in caves (particularly limestone caves) but probably also in buildings. Call shape is FM /CF/ FM, and peak call frequencies have been recorded at 22-25 kHz in Laos, 27-5-29-5 kHz in Vietnam, and 26-8 kHz in Guizhou, China. Call duration has been recorded at 60-5 milliseconds and 67-5 milliseconds in Vietnam.

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Least Concern on The IUCN Red List. Bourret’s Horseshoe Bat has been assessed separately and is also classified as Least Concern. The King Horseshoe Bat is considered widespread and relatively common throughout its distribution. Records continue to expand its distribution. It seems to cope well in secondary habitats and agricultural settings but might be threatened by pesticide use and cave tourism. General deforestation also seems to be a major threat because it forages heavily in forest habitats.

Bibliography. Bates, Bumrungsri & Csorba (2008 a), Csorba et al. (2003), Eger & Fenton (2003), Francis (2008 a), urey, Mackie & Racey (2009), Mao Xiuguang et al. (2007), Oo Sai-Sein-Lin et al. (2017), Smith & XieYan (2008), Smith, Johnston, Jones & Rossiter (2008b), Sun Keping et al. (2008), Tu Vuong Tan, Hassanin et al. (2017), Wu Hui et al. (2015), WuYi &Thong Vu Dinh (2011), Zhang Libiao, Jones et al. (2009), Zhang Lin et al. (2018), Zhao Huihua, Zhang Shuyi, Zhou Jiang & Liu Zimin (2002), Zhao Huihua, Zhang Shuyi, Zuo Mingxue & Zhou Jiang (2003).

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).

Subspecies and Distribution. . r. rex G. M. Allen, 1923 - S & SE China (Sichuan, Chongqing, Guizhou, Hunan, Guangxi, and Guangdong). . r. paradoxolophus Bourret, 1951 — SE China (E Guangxi and probably E Yunnan), E Myanmar , N Thailand , N & C Laos , and N & C Vietnam .