159.

Blanford’s False Serotine

Hesperoptenus blanfordi

French: Sérotine de Blanford / German: Blanford-Scheinbreitfligel / Spanish: Hesperoptero de Blanford

Other common names: Blanford’s Bat, Least False Serotine

Taxonomy. Vesperugo (Hesperoptenus) blanfordi Dobson, 1877,

“Tenasserim,” Myanmar.

Subgenus Milithronycteris . See G. doriae . T. Gorfol and colleagues in 2019 found H. blanfordi sister to Arielulus circumdatus . Monotypic.

Distribution. SE Myanmar (Tenasserim) S through W and peninsular Thailand to Peninsular Malaysia, with scattered records from C & S Laos (Phou Hin Poun National Biodiversity Conservation Area and Xe Pian National Protected Area), SW & S Cambodia (Cardamom and Elephant Mts), S Vietnam (Dong Nai and Ba Ria-Vung Tau provinces and Phu Quoc I), and Borneo (Niah National Park in Sarawak, Witti Range and Sepilok in Sabah, and East Kalimantan).

Descriptive notes. Head-body 37-45 mm, tail 33-34 mm, ear 11-12 mm, hindfoot 4-5-6-6 mm, forearm 24-29 mm; weight 5-5-8 g. Blanford’s False Serotine is the smallest species of Hesperoptenus, appearing similar to bamboo bats (7ylonycteris spp.) with very short forearms and well-developed adhesive pads on thumbs but not on feet (unique among Hesperoptenus). Pelage is rather sleek, with glossy sheen. Upperparts are dark brown, with reddish tinge, and underparts are slightly paler. Fur on shoulders is sparser but longer and lighter. Ears and muzzle are grayish brown. Internarial region and upper surface of forearm are densely haired. Wing membranes are grayish brown or brown. Ears are short and triangular. Tragus is short, blunt, and anteriorly directed, with length subequal to width. Calcar has well-developed lobe, with transverse septum. Thumb pads are thickened, dark-brown, and kidney-shaped. Head is slightly pointed, with smoothly sloping profile. Nostrils are widely separated. Baculum has long, slender, ventrally fluted shaft, tip is expanded vertically and horizontally, and base is expanded into broad paired flanges separated by shallow V-shaped aperture. There are differences in baculum size between Malayan and Bornean populations, the latter smaller in body and teeth measurements. Skull is very small, with wide flattened braincase and lambdoid ridges but no sagittal crest. Frontal part of face is flat, without any flexure. I? is greatly reduced. I’ is displaced inward,so that I and C' are in contact. Condylo-canine lengths are 11-8-12-5 mm, and maxillary tooth row lengths are 4-2—-4.-4 mm. Chromosomal complement has 2n = 32 and FN = 54 in Malaysia and 2n = 32 and FN = 56 in Thailand.

Habitat. Wide variety of habitats from lowland wet forests to dry dipterocarp forests and hill forests from sea level up to elevations of ¢. 1300 m. In Vietnam, recorded in heavily disturbed agricultural landscapes and usually associated with small rivers and streams.

Food and Feeding. Blanford’s False Serotine is insectivorous.

Breeding. In Vietnam, pregnant Blanford’s False Serotines were recorded at the end of April. Three captive females had one young each.

Activity patterns. Blanford’s False Serotines are nocturnal and fly ¢.7-10 m aboveground, usually in open spaces. In Krau Wildlife Reserve, Malaysia, they were mistnetted over rivers. In Malaysia, they roost in entrances of limestone caves in hill forests. Presence of thumb pads suggests they can hang and move on smooth surfaces and might roost in bamboo. As very skillful runners, they often try to reach nearby hideouts quickly. During the day, they preferred to roost in horizontal columns, where they often slept with their bellies up. Unusual for Vespertilionidae, Blanford’s False Serotine has two call types, with similar frequency modulation but different frequencies, which frequently change in a regular way. This alternation was heard in nine of eleven individuals after release; only high-frequency calls could be observed for the other two. High-frequency pulses (durations of 3-9 milliseconds) started at ¢.105 kHz at the maximum and ended between 40 kHz and 45 kHz; low-frequency calls (durations of 3-10 milliseconds) started at c.105 kHz but swept down to 31-37 kHz. Reported lower starting frequencies might result from larger distances between microphone and bat during recording (high-frequency calls with mean peak frequency of 44 kHz and duration of 6-6 milliseconds and low-frequency calls with peak of 36 kHz and duration of 8-3 milliseconds).

Movements, Home range and Social organization. Blanford’s False Serotine lives in small colonies, with less than ten individuals.

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

Bibliography. Abramov et al. (2007), Amador et al. (2018), Boitani et al. (2006), Borisenko & Kruskop (2003), Corbet & Hill (1992), Francis (2008a), Francis et al. (2010), Fukuda et al. (2009), Gorfdl et al. (2019), Hassanin et al. (2018), Heller (1989), Heller & Volleth (1989), Hendrichsen, Bates & Hayes (2001), Hill (1976), Hill & Francis (1984), Hutson, Kingston, Francis, Banks & Csorba (2008), Kingston, Jones et al. (2003), Kingston, Lim & Zubaid (2006), Koubinova et al. (2013), Kruskop (2013a), Lim et al. (2017), Matveev (2005), McBee et al. (1986), Medway (1983), Payne et al. (1985), Pearch & Writer (2009), Phillipps & Phillipps (2016), Robinson (1998), Robinson & Webber (1998), Shazali et al. (2016), Simmons (2005), Volleth etal. (2001).