Rhinolophus microglobosus, Csorba & Jenkins, 1998

Burgin, Connor, 2019, Rhinolophidae, Handbook of the Mammals of the World – Volume 9 Bats, Barcelona: Lynx Edicions, pp. 280-332 : 322

90 . Vietnamese Brown Horseshoe Bat

Rhinolophus microglobosus

French: Rhinolophe à petit nez I German: Braune Vietnam-Hufeisennase / Spanish: Herradura de Vietnam

Other common names: Indochinese Brown Horseshoe Bat, Indochinese Lesser Brown Horseshoe Bat

Taxonomy. Rhinolophus stheno microglobosus Csorba &Jenkins, 1998 ,

“ Na Hang Nature Reserve , Tuyen Quang Province, Vietnam, between 22°16’ and 22°31’N, 105°22’ and 105°29’E, altitude 100-1082 m.”

Rhinolophus microglobosus is currently included in the euryotis species group, due to its close relationship with R. stheno . It has typically been treated as a subspecies of R.stheno , but is now recognized as a distinct species on morphological grounds according to P. Soisook and colleagues in 2008. Some recently collected specimens from China most likely represent this species, although their echolocation calls fall within the range of R.stheno ; further comparison is needed. Monotypic.

Distribution. Myanmar, S China (Yunnan), Thailand, Laos, Cambodia, and at least N & C Vietnam; exact distributional limits are uncertain.

Descriptive notes. Head-body 39-9-60- 1 mm, tail 14-5—22- 4 mm, ear 12-3-17- 6 mm, hindfoot 6-9- 5 mm, forearm 41-4—46- 3 mm; weight 5-9 g. Dorsal pelage is grayish brown to yellowish brown, and ventral pelage is pale brown. Ears are small to medium in length. Noseleaf has long, straight-sided lancet with cuneate tip and median septum that is wider than middle pockets; connecting process is rounded and covered in scattered long hairs; sella has nearly parallel sides; horseshoe is wide (6-9— 9 mm), covering much of muzzle, and has shallow median emargination and conspicuous secondary leaflets; outer ring of horseshoe is darker than paler area around the nostrils. Lower lip has three mental grooves. Skull is slender with subequal zygomatic and mastoid widths (narrower than in Lesser Brown Horseshoe Bat, R. stheno )', anterior median rostral swellings are high and abrupdy elevated (their anterior wall is perpendicular to upper tooth row); posterior swellings are reduced rostral profile is posteriorly very concave; sagittal crest is moderately developed (anterior median swellings are less inflated and narrower than in the Lesser Brown Horseshoe Bat); frontal depression is deep (shallower than in the Lesser Brown Horseshoe Bat); supraorbital crests are high; interorbital region is very narrow. P2 is large, with a distinct cusp, and is within tooth row, which separates C1 and P4; P3 is small and completely displaced, allowing P2 and P4 to touch. Karyotype is 2n = 62 ( Thailand).

Habitat. Mainly known from limestone karsts and lowland to hill evergreen forests. Recorded at elevations from sea level up to 1082 m.

Food and Feeding. No information.

Breeding. A pregnant female was captured in late February, and a lactating female in May in central Thailand.

Activity patterns. Vietnamese Brown Horseshoe Bats are nocturnal and roost in caves during the day. Torpid individuals have been reported in their day roosts in July. Call shape is FM/CF/FM with a peak F recorded at 87-2 kHz in Yunnan, China, 94-1-100-3 kHz in northern Thailand, 85-95 kHz in western Thailand, 92-97 kHz and 101-5-101-7 kHz in two areas of Myanmar, and 95 kHz in Laos.

Movements, Home range and Social organization. The Vietnamese Brown Horseshoe Bat roosts in small or large colonies with up to c.1200 individuals reported in one cave in Thailand. Roosts with 10-50 individuals are common.

Status and Conservation. Classified as Least Concern on The IUCN ed List. There are currently no major threats facing this widespread species, although roost disturbance may locally affect some populations. The Vietnamese Brown Horseshoe Bat is apparendy hunted in north-eastern Thailand, but this probably does not have a significant effect on the population.

Bibliography. Csorba & Jenkins (1998), Csorba et al. (2003), Francis (2008a), Harada et al. (1985), Kruskop (2013a), Soisook (2008, 2017a), Soisook et al. (2008), Stoffberg et al. (2010), Zhang Jinshuo et al. (2005), Zhang Libiao, Jones et al. (2009).

Figures

On following pages: 78. New Guinea Broad-eared Horseshoe Bat (Rhinolophus euryotis); 79. Sulawesi Broad-eared Horseshoe Bat (Rhinolophus tatah; 80. Poso Horseshoe Bat (Rhinolophus belligerator); 81. Bornean Woolly Horseshoe Bat (Rhinolophus proconsulis); 82. Arcuate Horseshoe Bat (Rhinolophus arcuatus); 83. Philippine Forest Horseshoe Bat (Rhinolophus inops); 84. Small Rufous Horseshoe Bat (Rhinolophus subrufus); 85. Large Rufous Horseshoe Bat (Rhinolophus rufus); 86. Intermediate Horseshoe Bat (Rhinolophus affinis); 87. Homfray's Horseshoe Bat (Rhinolophus andamanensis); 88. Croslet Horseshoe Bat (Rhinolophus coelophyllus); 89. Shamel's Horseshoe Bat (Rhinolophus shameli); 90. Vietnamese Brown Horseshoe Bat (Rhinolophus microglobosus); 91. Lesser Brown Horseshoe Bat (Rhinolophus stheno).

Distribution. Myanmar , S China (Yunnan), Thailand , Laos , Cambodia , and at least N & C Vietnam ; exact distributional limits are uncertain.