Rhinolophus cornutus, Temminck, 1834

Burgin, Connor, 2019, Rhinolophidae, Handbook of the Mammals of the World – Volume 9 Bats, Barcelona: Lynx Edicions, pp. 280-332 : 310-311

63 . Little Japanese Horseshoe Bat

Rhinolophus cornutus

French: Rhinolophe cornu I German: Kleine Japan-Hufeisennase / Spanish: Herradura pequeno de Japon

Other common names: Japanese Lesser Horseshoe Bat, Japanese Little Horseshoe Bat

Taxonomy. Rhinolophus cornutus Temminck, 1834 ,

Japan .

Rhinolophus cornutus is included in the pusillus species group along with R pumilus, R.perditus , R. monticolus , R. shortridgei , R. monoceros , R. pusillus , R. subbadius , R. convexus , R. cognatus , R. refulgens , and R. lepidus . The species group is sister to a clade including the megaphyllus , philippinensis, and macrotis groups. Genetic distance between. cornutus , R.pumilus , R.perditus , R. monoceros , and R.pusillus is small and most species overlap in echolocation frequency, which has led several authors to include all these species within R. pusillus . However, there is morphological evidence supporting the species status of these taxa, and also suggesting that R.pusillus as here constituted may actually be a species complex. Rhinolophus perditus is sometimes alone treated as a subspecies of R. comutus , but it is here recognized as a distinct species, based on morphological and genetic data. Two subspecies are recognized.

Subspecies and Distribution.

R c. cornutus Temminck, 1834 — Japan (Hokkaido, Honshu, Shikoku, Kyushu , Okushirito , Sado , Tsushima , Fukuejima , Kuchinoerabujima , Nakano , Iki , Izu , Niijima , Miyakejima , Mikurajima , and Hachijöjima Is ).

R c. orii Kuroda, 1924 - SJapan on Amami Is (Amami-Oshima, Kakeromajima, Tokunoshima, and Okinoerabujima).

There is one record from Guangxi, S China, but this is considered dubious and is probably based on misidentification.

Descriptive notes. Head-body 36-56- 2 mm, tail 15-5-29- 5 mm, ear 14-19- 3 mm, hindfoot 7-10- 5 mm, forearm 37- 6-42 mm. Females have larger forearms and cranial measurements than males, and there is a decreasing cline in forearm length from north to south. Pelage is woolly and glossy, dorsally grayish brown (base of hairs light beige), ventrally similar but paler. Ears are moderate-sized. Noseleaf has concave-sided lancet; connecting process is subtriangular and curved; sella is pandurate, being constricted above middle, with a broadly rounded tip; horseshoe is not very broad (6-2-6- 7 mm), has no lateral leaflets, and short, narrow median emargination. Lower lip has three mental grooves. Baculum is 4-2-4- 8 mm long and has very deep dorsal notch on basal cone, with small ventral notch; shaft is nearly cylindrical and is bent on distal one-half. Skull is long and narrow, and zygomatic width is subequal to mastoid width; anterior median swellings are small and subcircular; posterior compartments are moderate in size; rostral profile slopes gendy posteriorly or is rarely almost straight; sagittal crest is weakly to moderately developed; frontal depression varies from moderately to fairly deep; supraorbital crests are conspicuous but not generally sharp. P2 is comparatively large (although still minute) and within tooth row, P3 is medium-sized to small and lies nearly in tooth row. Chromosomal complement has 2n = 62 and FNa = 60.

Habitat. Temperate woodland habitats.

Food and Feeding. Litde Japanese Horseshoe Bats feed on a variety of insects, including Diptera , Lepidoptera, Coleoptera, Trichoptera , Orthoptera , and Araneae . Their diet shifts through the year, and during hibernation they often feed on camel crickets ( Rhaphidophoridae ) within caves and on Diptera ( Mycetophilidae , Tipulidae , and Trichoceridae ) that emerge in winter and early spring outside the caves.

Breeding. LitdeJapanese Horseshoe Bats exhibit restricted seasonal monoestry. Males and females roost together for a small portion of the year to breed, before females form maternity colonies in summer. Females give birth to a single young. Young begin to feed themselves by c.22 days and are weaned by c.45 days. Females usually become sexually mature at 28 months but do not generally reproduce until their third year. The oldest recorded individual was a 21-year-old male.

Activity patterns. The LittleJapanese Horseshoe Bat roosts during the day in caves, abandoned mines, unused tunnels, bomb shelters, and underground channels; it forages through the night. On Kyushu, in late autumn individuals increase their weight by 28-2— 33-8% compared to summer; they hibernate through winter throughout their distribution. Hibernating bats prefer to roost in caves with relatively high ambient temperatures (9-15°C) and humidity (85-100%). Hibernating bats are relatively light sleepers and are aroused easily compared to GreaterJapanese Horseshoe Bats (A m /> jbon). Hibernating bats regularly arouse themselves to forage outside the cave. Search call shape is FM/ CF/CF with a peak F of 103-120 kHz that increases gradually from north to south; peak frequencies were recorded at 103-104 kHz in Aomori Prefecture, 106-108 kHz on northern Honshu, 108-109 kHz on Yakushima, and 109—111 kHz on Amami-Oshima.

Movements, Home range and Social organization. Littlejapanese Horseshoe Bats roost in sex-segregated and maternity colonies consisting of tens to hundreds of individuals.

Status and Conservation. Not assessed as a separate species on The IUCN ed List, where it is included under the Least Horseshoe Bat (A pusillus } as Least Concern. The Littlejapanese Horseshoe Bat does not seem to be facing any major threats at present, and is rather common throughout much of its range.

Bibliography. Ando eta/. (1983), Chen Shiangfan eta/. (2006), Csorba eta/. (2003), Funakoshi &Takeda (1998), Funakoshi & Uchida (1980), Funakoshi et a/. (2010), Hutson, Kingston & Walston (2008), Kurohmaru et al. (2002), Li Gang eta/. (2006), Maeda (1988), Morigaki eta/. (2001), Ohdachi eta /. (2015), WuYi, Motokawa et al. (2012), Xu Lijie et al. (2008), Yamamoto (1986), Yokoyama & Uchida (1979), Yoshiyuki (1989), Zhang Lin et al. (2018), Zhang Weidao (1985).

Figures

On following pages: 52. Eastern Horseshoe Bat (Rhinolophus megaphyllus}; 53. Insular Horseshoe Bat (Rhinolophus keyensis}; 54. Yellow-faced Horseshoe Bat (Rhinolophus virgo}; 55. Madura Horseshoe Bat (Rhinolophus madurensis}; 56. Sulawesi Horseshoe Bat (Rhinolophus celebensis}; 57. Robinson's Horseshoe Bat (Rhinolophus robinsoni); 58. Indochinese Horseshoe Bat (Rhinolophus chasem); 59. Anamban Horseshoe Bat (Rhinolophus nereis}; 60. Bornean Horseshoe Bat (Rhinolophus borneensis); 61. Malayan Horseshoe Bat (Rhinolophus malayanus}; 62. Acuminate Horseshoe Bat (Rhinolophus acuminatus}; 63. Acuminate Horseshoe Bat (Rhinolophus acuminatus}; 64. Little Japanese Horseshoe Bat (Rhinolophus cornutus}; 65. Yaeyama Horseshoe Bat (Rhinolophus perditus}; 66. Mountain Horseshoe Bat (Rhinolophus monticolus}; 67. Shortridge's Horseshoe Bat (Rhinolophus shortridgei}; 68. Formosan Horseshoe Bat (Rhinolophus monoceros}; 69. Least Horseshoe Bat (Rhinolophus pusillus}; 70. Little Nepalese Horseshoe Bat (Rhinolophus subbadius}; 71. Convex Horseshoe Bat (Rhinolophus convexus}; 72. Andaman Horseshoe Bat (Rhinolophus cognatus}; 73. Glossy Horseshoe Bat (Rhinolophus refulgens}; 74. Blyth's Horseshoe Bat (Rhinolophus lepidus};

Subspecies and Distribution. R c. cornutus Temminck, 1834 — Japan (Hokkaido, Honshu, Shikoku, Kyushu , Okushirito , Sado , Tsushima , Fukuejima , Kuchinoerabujima , Nakano , Iki , Izu , Niijima , Miyakejima , Mikurajima , and Hachijöjima Is ). R c. orii Kuroda, 1924 - SJapan on Amami Is (Amami-Oshima, Kakeromajima, Tokunoshima, and Okinoerabujima). There is one record from Guangxi, S China , but this is considered dubious and is probably based on misidentification.