Hipposideros ridleyi, Robinson and Kloss, 1911

Bumrungsri, Sara, Harrison, David L., Satasook, Chutamas, Prajukjitr, Amorn, Thong-Aree, Siriporn & Bates, Paul J. J., 2006, A review of bat research in Thailand with eight new species records for the country, Acta Chiropterologica 8 (2), pp. 325-359 : 344

Hipposideros ridleyi Robinson and Kloss, 1911

Ridley’s leaf nosed bat

Hipposideros ridleyi Robinson and Kloss, 1911: 241, Botanical Gardens, Singapore.

New Material

PSU-M05.12 (field no. SB030222), ♂, 22 February 2003, Wildlife Research Sta- tion, Bala Forest , Wang, Narathiwat Prov- ince, 05°47’45”N, 101°49’56”E, collected by S. Bumrungsri and members of the Hala- Bala bat research team.

Taxonomic notes

This is a medium-small hipposiderid bat, with a forearm length in the recent specimen of 47.9 mm ( Table 4) (47.2–49.8 mm in Francis et al., 1999 b). The pelage is dark brown on both the dorsal and ventral aspects ( Fig. 2a ). The ears are large and broad (23 mm long × 20 mm wide). The an- terior noseleaf, which lacks supplementary leaflets, is wide (7.8 mm) and almost com- pletely covers the muzzle. The internarial septum is expanded into a large circular disc (diameter = 2.74 mm). This clearly dif- fers from the ovoid shape of its sibling spe- cies, H. orbiculus , which is also known from peninsular Malaysia ( Francis et al., 1999 b). The narial lappets are well devel- oped and form a pocket encircling the nos- trils. The skull is elongated, with slightly elevated narial swellings. The first upper premolar (P2) is small and situated within the toothrow.

Distribution and Ecological Notes

Hipposideros ridleyi is currently known from peninsular Malaysia, Singapore, Bor- neo (Sabah and Sarawak) ( Simmons, 2005). This is the first confirmed record from Thailand.

The voucher specimen from Thailand was captured together with a pregnant female (forearm length of 50.2 mm) in a harp trap set along a nature trail in Ba- la Forest. The local area includes many streams, which join together and become a small peat swamp (2 ha in size). Much of the ground layer is densely covered with rattans and palms. The general habitat is pristine lowland evergreen forest at the elevation of 100 m a.s.l. and the topography is essentially flat. In peninsular Malaysia, a number of specimens was also collected from peat swamp forest and along trails in lowland dipterocarp forest ( Zubaid et al., 1986). This habitat type is currently threat- ened throughout Southeast Asia. In Thai- land, breeding occurs as early as late Febru- ary. Females were lactating between April and May ( Kemper, 1988) and July in Bor- neo ( Francis et al., 1999 b). Medway (1969) suggested it may roost in caves, although there is no evidence to support this sugges- tion. It was found roosting in road culverts in peninsular Malaysia ( Gould, 1978). There are apparently no caves in the vicini- ty of the area of collection in Thailand.

Figures

FIG. 2. A general view of part of Hala Forest and six bat species new to the fauna of Thailand: A — Hipposideros ridleyi, B — Myotis hermani, C — Murina suilla, D — Murina aenea, E — Kerivoula pellucida, F — Mops mops