141.

Bronze Sprite

Arielulus circumdatus

French: Farfadet a oreilles bordées / German: Bronzefarbene Elfenfledermaus / Spanish: Arielulus bronceado

Other common names: Black-gilded Pipistrelle

Taxonomy. Vespertilio circumdatus Temminck, 1840,

“L’ile de Java, dans le district sauvage de Tapos,” Indonesia.

Current members of Arielulus were long treated as a species group within Pipustrellus, or sometimes Eptesicus, on the grounds of karyology and bacular morphology. In 1987, Arielulus was established as a subgenus within Pipustrellus. In 1999, G. Csorba and Lee Lingling concluded that Arielulus was distinct from Pipistrellus, raising it to generic rank, with Thainycteris as a junior synonym; these two were later split. Arielulus societatis and A. cuprosus were at times regarded as merely lowland forms of A. circumdatus . Chinese populations have sometimes been separated as race drungicus, but they differ only in minor dental characters; Vietnamese (Dalat Plateau) specimens are slightly smaller with less red than those from Nepal; more research is needed to assess the degree of intraspecific variation. Monotypic.

Distribution. Patchily distributed in Nepal, NE India (Sikkim, Assam, Meghalaya, and Mizoram), Myanmar (Kachin State), SC China (Yunnan and Guangdong), Thailand, Vietnam, Cambodia, Peninsular Malaysia (Fraser’s Hill in Pahang Province), and Java; it may occur more widely in S China.

Descriptive notes. Head-body 46-58 mm,tail 36-46 mm, ear 10-15 mm, hindfoot 7-10 mm, forearm 38-6—44-3 mm; weight 6-2-17-3 g. The Bronze Sprite resembles some serotines ( Neoromicia spp.) in appearance, but with broader and short muzzle and very distinct pelage. Fur is long and soft; upperparts essentially black, but some hairs have distinctive ferruginous tips, giving an almost orange sheen to head and back; ventral surface is uniform brown, paler than back (hair roots slightly darker than tips). Ears are medium-sized, with distinct lobe at base near eye, dark brown with pale (buffy) anterior and posterior margins; tragus similar to that of Hypsugo, less than one-half ear length, bluntly pointed on tip, slightly convex posteriorly and concave anteriorly, also with pale rims. Membranes are uniform dark brown and essentially naked. Baculum is very small, Y-shaped, with paired basal lobes and short shaft. Skull is large; rostrum is very broad, relatively short, and sharply angulated inward posterior to lacrimal projections; distinct supraorbital and postorbital ridges are present; braincase is large, with slight indication ofsagittal and lambdoid crests; in dorsal profile, there is concavity in supraorbital region; zygomata are broad, especially posteriorly; palatal length exceeds breadth; and basisphenoid pits are well developed. P? varies in size, and is displaced inward from tooth row, occasionally absent or present only on one side, and situated in angle between C' and P*; I* is robust and bicuspidate; C' is robust and lacks a secondary cusp; P, is in tooth row, and has one-third crown area of P,. Condylo-canine lengths are 12:2-15-6 mm, maxillary tooth row lengths are 5-5—6-5 mm. Dental formula for all species of Arielulusis 12/3, C1/1,P1-2/2,.M 3/3 (x2) = 32-34.

Habitat. Montane forests and secondary teak forest. In Myanmar, found at 1940 m in temperate forest consisting of oaks, laurels, and rhododendrons. In Vietnam, found in wet evergreen forests and mixed broadleaf and coniferous forest (Dalat Plateau, 1400-1700 m). In Cambodia, recorded in undisturbed forest. In Nepal, found in a partly deforested area and in primary forest. In Nanling Mountains, Guangdong, southern China, occurs in broadleaf evergreen forests. Recorded at elevations of 1300-2100 m.

Food and Feeding. Feces collected in Vietnam (Danim River Valley) contained fragments of thick, bright chitin, indicating the presence of large Anomala beetles ( Coleoptera) in its diet.

Breeding. In Nepal, in May each of four captured females carried one near-term embryo in the right uterine horn. The breeding season in Guangdong may start in June or July, with subadults captured in July.

Activity patterns. Bronze Sprites are nocturnal. In Nepal they have been observed in a ravine along the Bhurungdi River, leaving their roost to forage, flying downstream at and above canopy level; some were observed hunting around the canopy in small clearings in montane forest. Flight is fast and less maneuverable than that of Pipustrellus. In Vietnam, the species was usually observed soon after sunset, foraging along the forest edges or over clearings and corn fields at ¢.5-20 m aboveground. In primary Fokienia (Cupressaceae) forest (1300 m) at Vu Quang, central Vietnam, seen flying at canopy or subcanopy level above a stream, in relatively uncluttered space. Echolocation call is fairly high-intensity, probably with a steep to shallow FM sweep, and maximum energy at ¢.45-50 kHz (frequency range not determined). In Vietnam, echolocation calls were shallow FM with maximum energy at 35-40 kHz. In China, FM calls with frequencies of 36-112-6 kHz (main frequencies 52-1-62-3 kHz).

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Least Concern on The IUCN Red List.

Bibliography. Abramov et al. (2010), Bates & Harrison (1997), Bates, Bumrungsri et al. (2008), Bates, Nwe Tin et al. (2005), Boitani et al. (2006), Corbet & Hill (1992), Csorba & Lee Lingling (1999), Csorba et al. (1999), Eller man & Morrison-Scott (1966), Francis (2008a), Francis et al. (2010), Gorfol et al. (2019), Guo Weijian et al. (2017), Heller & Volleth (1984, 1989), Hendrichsen, Bates & Hayes(2001), Hill & Francis (1984), Hill & Harrison (1987), Kruskop (2013), Lim et al. (2017), Matveev (2005), Medway (1983), Mohd-Hanif et al.(2015), Pearch & Writer (2009), Simmons (2005), Smith & Xie Yan (2008), Wang Yingxiang (1982, 2003), Zhang Libiao et al. (2014).