143.

Coppery Sprite

Arielulus cuprosus

French: Farfadet de Bornéo / German: Kupferfarbene Elfenfledermaus / Spanish: Arielulus de Borneo

Other common names: Coppery Pipistrelle

Taxonomy. Pipistrellus cuprosus Francis & Hill, 1984,

*Sepilok, Sabah, 5°52’ N, 117°56’ E,” Borneo, Malaysia.

Previously considered a lowland form of A. circumdatus . In 2018, in a study by L.. I. Amador and colleagues, A. cuprosus clustered with Thainycteris aureocollaris (under Arielulus) and Hesperoptenus tomes: in a clade related to Rhyneptesicus nasutus and Glauconycterts, further work is needed on the relationships of the three Arielulus species. Monotypic.

Distribution. Known from a few localities in Borneo (Sabah and Sarawak), including Sepilok Forest Reserve, Batu Punggul, Mt Mulu, Similajau National Park, Lanjak Entimau Wildlife Sanctuary, Mt Penrisen, Kubah National Park, and Samunsam Wildlife Sanctuary. A record of Pipistrellus sp. from Kalimantan may also be this species.

Descriptive notes. Head-body 57 mm (one specimen), tail 35-42 mm, ear 11-12 mm, hindfoot 7-9 mm, forearm 34-5-37 mm; weight 5-3-6-5 g. The Coppery Sprite resembles the Social Sprite ( A. societatis). It has distinctive long, thick fur dorsally, with black or blackish-brown hair bases, and reddish-orange or coppery tips; pelage over crown of head is similarly tipped, but slightly paler and more yellowish than on back; underparts are dark brown or brown, hairs tipped with yellowish white on upper chest near shoulders, elsewhere with grayish white. Flight membranes are black; fur extends on dorsal surface of uropatagium but forearms and tibiae are not haired. Ears and tragus are dark brown with buffy rims; ears are moderately large, with distinct lobe at base near eye. Baculum is very small, with short, slender shaft, tip slightly upcurved, shaft supported by paired basal flanges separated posteriorly by shallow, rounded emargination; baculum is like that of the Social Sprite, but smaller;it differs from that of the Bronze Sprite ( A. circumdatus) in its higher, more angular upper margin and more angular basal lobes. Skull is small, with rounded, globular and inflated braincase; postorbital region is wide, supraorbital ridges are weakly developed. Dentition is like that in the Social Sprite, but smaller. P? is very tiny (sometimes lacking) and displaced inward so that C' and P* are touching. Condylo-basal lengths are 12-9-13 mm, maxillary tooth row lengths are 4-8—4-9 mm.

Habitat. Lowland dipterocarp and montane forest. Found in understory oftall forest, along the edge of a steep cliff, and in a forest gap at high elevation.

Food and Feeding. No information.

Breeding. No information.

Activity patterns. The Coppery Sprite is nocturnal. It is probably a canopy species. Mistnetted over a river in Lanjak Entimau and Samunsam wildlife sanctuaries (Sarawak).

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Vulnerable on The IUCN Red List, as its area of occupancy is estimated to be less than 2000 km?2. Less than 20 individuals have been captured at only eight locations in Sabah and Sarawak. Extent and quality of its habitat seem to be in continuous decline.

Bibliography. Abdullah et al. (2010), Amador et al. (2018), Benda (2010a), Boitani et al. (2006), Corbet & Hill (1992), Heller &Volleth (1989), Hill & Francis (1984), Hill & Harrison (1987), Khan, Swier et al. (2008), Khan, Tahir et al. (2017), Kumaran et al. (2011), McArthur (2016b) Mohd-Azlan et al.(2008) Payne et a/.(1985), Simmons (2005), Suyanto & Struebig (2007), Tingga et al. (2008).