Arielulus societatis

142.

Social Sprite

Arielulus societatis

French: Farfadet des sociétés / German: Soziale Elfenfledermaus / Spanish: Arielulus social

Other common names: Benom-gilded Pipistrelle, Social Pipistrelle

Taxonomy. Pipistrellus societatis Hill, 1972,

Malaysia, “Base Camp, Gunong Benom, Pahang, Malaya [= Malaysia], 3°51'N, 102°11'E, 800 ft. [= 244 m].”

Previously considered merely a lowland form of A. circumdatus, but this opinion was rejected on the basis of morphological characteristics. Monotypic.

Distribution Known only from Peninsular Malaysia, including Selangor (Ulu Gombak) and Pahang (Sungai Tekam Forest Reserve, Gunung Benom, and Krau Wildlife Reserve) provinces. Also listed from Fraser’s Hill Forest Reserve, Pahang; but this record needs verification.

Descriptive notes. Head-body 41-44 mm, tail 33-37 mm, ear 8-5-9 mm, forearm 36-6—40-6 mm; weight 4-3-8-5 g. The Social Sprite closely resembles the Bronze Sprite (A. circumdatus), but with smaller forearms, post-palatal extension, tooth row, and rostrum. Dorsal pelage is blackish brown with orange or bronze tipping (hairs basally brown, blackish brown for most of length, and tipped orange or bronze); crown pelage is orange-tipped but with a small area of straw-color; underparts are dark brown, tipped grayish white. Ears are large and bluntly rounded, with posteriorly directed basal lobe; tragus is large, and ears have yellowish-white rims, as in congeners. Wings are uniformly black. Baculum is Y-shaped with paired basal lobes and short shaft. Skull is short and wide, with rounded, rather globular braincase, inflated and elevated in frontal region; interorbital region wide; supraorbital region crests only faintly defined, terminating in small tubercles; rostrum is shorter, and narrower than in the Bronze Sprite, with more inflated braincase. Dentition is similar to that of the Bronze Sprite, less massive, with M® reduced, and posterior cusp virtually absent. Condylo-basal lengths are 13-9-14-8 mm; maxillary tooth row lengths are 5-2-5-6 mm. Chromosomal complement has 2n= 50 and FN= 48.

Habitat. Recorded in primary lowland and hill forests, and secondary forests. The type specimen was found near a stream at 266 m.

Food and Feeding. No information.

Breeding. No information.

Activity patterns. Nocturnal. It was mist-netted above small ford on a tributary of the Gombak River. In Selangor, found roosting in a tree-trunk hole beside a forest stream.

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Vulnerable on The IUCN Red List because its extent of occurrence is less than 20,000 km?, its range is fragmented across forest patches, and there is continuing decline in the extent and quality of its habitat due to rapid deforestation. It occurs in Krau Wildlife Reserve.

Bibliography. Bates, Francis & Csorba (2008), Boitani et al. (2006), Corbet & Hill (1992), Francis (2008a), Heller & Volleth (1984, 1989), Hill (1972, 1983), Hill & Francis (1984), Hill & Harrison (1987), Kingston, Francis et al. (2003), Kingston, Lim & Zubaid (2006), Lim et al. (2017), Medway (1983), Mohd-Hanif et a/.(2015), Simmons (2005).