Abstract
A female Hypsugocf.vordermanni was caught at a stream near a village road in Mantailang, Crocker Range Park, Sabah, on 12 November 2018. This bat is a new record for the national park and the second record for Sabah. It was first recorded from Banggi Island, Kudat, in 1991. The species' few records throughout its range is most likely due to sampling effort bias towards forest interior and cave-dwelling species, as this species is more likely an edge-space aerial forager. It is morphologically similar to Peninsular Malaysia's Hypsugomacrotis, but the latter has never been reported from Borneo. Therefore, additional specimen collection and molecular data for H.cf.vordermanni are needed for further species confirmation. More information on H.vordermanni ecology is also crucial in aiding the management plan for this species as it is currently classified as Data Deficient by the IUCN.
Keywords: white-winged pipistrelle, Mantailang
Introduction
The vespertiolinid bats (family Vespertilionidae) are the most widespread bats worldwide (approximately 300 species) with 41 species from 14 genera occurring on Borneo Island, namely Arielulus, Falsistrellus, Glischropus, Hesperoptenus, Myotis, Philetor, Pipistrellus, Scotophilus, Tylonycteris, Murina, Kerivoula, Harpiocephalus, Phoniscus and Hypsugo (Phillipps and Phillipps 2018).
Hypsugovordermanni, the white-winged pipistrelle was first described as Vesperugovordermanni (Jentink, 1890c) from Belitung Island, Indonesia. It is a small-sized bat with a forearm recorded at 30.5 mm and a tail of 15.1 mm. It is a rare bat with only six specimens recorded from Samunsam, Sarawak (Payne et al. 1985, Francis and Hill 1986), Tanjung Puting, Kalimantan (Nash and Nash 1987), Belitung Island, Indonesia (Corbet and Hill 1992, Lim et al. 2016), Belalong, Brunei (Cranbrook and Edwards 1994), Banggi Island, Sabah (Nor 1996), and Kuching, Sarawak (Abdullah et al. 2000, Abdullah et al. 2010).
Until recently, it was included within Pipistrellus, from which Hypsugo differs in terms of its skull characteristics: smaller anterior premolar, shorter rostrum, smaller incisor and canine, with a myotodont pattern of the lower molars and broad and short baculum (Horáček and Hanák 1986, Francis 2008). H.vordermanni is described as having pale reddish-brown fur with darker bases, with large ears and a slightly hatchet-shaped tragus. The most prominent characteristic of this species is its translucent white wings, which become greyer near its body. Its anterior upper premolar is tiny and displaced inwards, which results in the canine and second premolar touching. It is similar to the Least Pipistrelle, P.tenuis, which has darker wings and a narrower tragus (Payne et al. 1985). H.vordermanni is also morphologically similar to H.macrotis, albeit the latter being relatively larger (Lim et al. 2016). It is noted that H.vordermanni feeds on insects and fish in rivers and calm seas (Phillipps and Phillipps 2018).
Materials and Methods
On 12 November 2018, a specimen of H.cf.vordermanni was caught in the mist net deployed across a stream near the village road in Mantailang, Crocker Range Park, Sabah, located at 5°10'15.13"N, 115°56 4.41"W (Fig. 1 and Fig. 2). The specimen was measured for its external characteristics, including: forearm length (FA), ear length (E), tragus length (TR), tibia length (TB), hind-foot length (HF), tail ventral length (TVL) and weight (Wt). Measurements were taken using the Mitutoyo Digital Caliper 500-196-30 (Mitutoyo, Japan) and weights were taken using a Pesola spring balance (Pesola AG, Sweden). Identification was done, based on keys in Payne et al. (1985).
Figure 1.
A map showing the location of Mantailang in Sabah, northeast Borneo. Mantailang is an area located near a village road within the border of the Crocker Range Park, a conservation area governed by the Sabah Parks in Sabah, Malaysian Borneo.
Figure 2.
A mist net was deployed across a river stream at the forest edge where the specimen was caught.
Results and Discussion
This is a new distributional record for H.cf.vordermanni in Sabah, Malaysian Borneo. This specimen is an adult, pregnant female, with external measurements of FA 33.58 mm, E 10.1 mm, TR 4.91 mm, TB 15.19 mm, HF 8.34 mm, TVL 35.68 mm and Wt 5.8 g (Fig. 3). It is a poorly known and rare species due to its very low capture rate and is categorised as Data Deficient by the IUCN (Görföl et al. 2016). The key characters which suggest specimen identification as H.cf.vordermanni is the translucent white wings and the hatchet-shaped tragus.
Figure 3.

Side profile of H.cf.vordermanni from Mantailang, Crocker Range Park, Sabah, Malaysian-Borneo. The hatchet-shaped tragus is one of the indicative features of this genus.
In Asia, only five species of Vespertilionidae bats are characterised by their "whitish' wings ("almost translucent" and "semi-translucent" included), including Hypsugovordermanni, H.macrotis, Kerivoulapellucida, K.hardwickii and Myotismacrotarsus (Rydell et al. 2020). The Kerivoula spp. are easily identified by their woolly fur, funnel-shapped ears, with long and pointed tragus. Meanwhile the Myotis spp. have shorter fur and forward-bent tragus (Phillipps and Phillipps 2018).
Hill (1983) and Francis and Hill (1986) remarked that H.vordermanni may be conspecific with H.macrotis, although the possibility of these two being distinct species was also acknowledged (Corbet and Hill 1992). It is noted that both H.macrotis and H.vordermanni have large ears and translucent wings (Fig. 4), with H.macrotis being relatively larger in size (Francis 2008).
Figure 4.

The white translucent wing of H.vordermanni against a white cloth as a background.
Translucent or whitish wings are suggested to function as camouflage against lit background, thus indicative of the species being an open space aerial forager (Rydell et al. 2020). H.macrotis is suggested to be an edge species (Lim et al. 2016), while the specimen described here was caught on the stream located in an open area at the forest edge near a village road.
A previous study recorded H.macrotis to have a forearm (FA) range of between 31.7 and 34.5 mm (n = 14), while H.vordermanni FA ranged from 31.0 to 33.4 (n = 2) (Lim et al. 2016). A recent study showed that cranial and craniodental characteristics between these two species slightly differ, where H.macrotis has a longer skull in comparison to H.vordermanni (Lim et al. 2016). The specimen described here showed a FA measurement exceeding the range for H.vordermanni by 0.18 mm and overlapped with the FA measurement for H.macrotis. However, the FA measurement range for H.vordermanni is based on only six (6) specimens (Table 1) and this is not comprehensive enough to represent the whole species. However, it is noted that additional specimen collection and retrieval of molecular data with detailed information on its ecology is a priority for confirming the species identification. Nevertheless, as of today, there is no known record of H.vordermanni from Peninsular Malaysia and vice versa for H.macrotis from Borneo. Therefore, it is concluded that the specimen recorded in this study is H.cf.vordermanni.
Table 1.
Detailed external character measurements for six (6) Hypsugovordermanni specimens recorded from Borneo, with the specimen found in this study, are presented. MZU/M= UNIMAS Museum Number; BMNH= British Museum (Natural History); FMNH= Field Museum of Natural History (Chicago); MCR= Mantailang Crocker Range; FA= Forearm; E= Ear; TB= Tibia; HF= Hind-foot; TVL= Tail ventral length; Wt=weight.
| Locality | Specimen ID | n | FA | E | TB | HF | TVL | Wt | Sex | Reference |
| Samunsam Wildlife Sanctuary, Sarawak, Malaysian Borneo; Belitung Island, Indonesia |
BM(NH) 82.547; RMNH 35570 (holotype) |
2 | 31.0 - 33.4 | - | - | - | - | - | - | Lim et al. (2016) |
| Bako National Park, Kuching, Sarawak | MZU/M/01460 | 1 | 32.4 | 8.9 | 15.7 | 5.0 | 14.6 | 4.5 | M | Abdullah et al. (2010) |
| Annah Rais Penrissen, Kuching, Sarawak | MZU/M/00126 | 1 | 33.0 | 13.3 | 16.8 | - | 15.0 | 5.0 | M | |
| Samunsam, Sarawak | BMNH 82.547 | 1 | 30.5 | - | - | - | - | - | F | Francis and Hill (1986) |
| Banggi Island, Sabah | 1 FMNH | 1 | 33.0 | - | - | - | 33.0 | 6.0 | M | Nor (1996) |
| Mantailang, Crocker Range Park, Tenom, Sabah | MCR051 | 1 | 33.6 | 10.1 | 15.2 | 8.3 | 35.7 | 5.8 | F | Current study |
It is a limitation for the current study that no skull measurement is available for the individual captured as it was released as it was a pregnant individual. No molecular data are available for the individual described here, thus limiting the verification options. Nevertheless, findings from this study contributed to additional distribution data of H.vordermanni in Sabah. More sampling efforts targeting the streams or water bodies near the forest edge or open areas are suggested to obtain more data on this rare or elusive species.
Acknowledgements
This project was sponsored by Nagao Environment Foundation (NEF), Japan Research Grant (GLA0015-2018), awarded to NHH on 28 March 2018. The field samplings for this study were conducted with permission from Sabah Parks, the statutory body governing CRP, under the permit reference TTS/IP/100-6/2 Jld. 10 (97) (NHH) and SaBC Access Permit JKM/MBS.1000-2/2 JLD.8 (156) (NHH). The authors would also like to acknowledge all the entities and individuals who were involved in the Sabah Parks Mantailang Scientific Expedition in 2018, during which the sampling in this study was conducted. Special thanks to Dr. Juliana Senawi (UKM) and Mr. Isham Azhar (TTU USA) for species reference; Prof. Gabor Csorba (Hungarian NHM) and Dr Lim Lee Sim (USM) for insightful comments and help on the specimen information; and PM Dr Faisal Ali Anwarali Khan (UNIMAS) for suggestions and comments on the manuscript.
Hosting institution
Universiti Malaysia Sabah, Sabah Parks
Funding Statement
Sabah Parks, Nagao Environmental Foundation (Grant no: GLA0015)
Author contributions
Manuscript writing: NHH; Data collection: NHH, USD, AA, MFMJ, JG, YTFT; Map preparation: LYC; Photographs: USD, AA
References
- Abdullah M T, Hall L S, Rahman M A, Marni W, Sait I. A note on the rare Pipistrellusvordermanni in Sarawak. Malaysian Borneo Malayan Nature Journal. 2000;54(4):375–376. [Google Scholar]
- Abdullah M T, Wong S F, Ketol B. Universiti Malaysia Sarawak Publication; 2010. Catalogue of mammals in the UNIMAS Zoological Museum. 52 pp. [ISBN: 978-967-5527-02-9] [Google Scholar]
- Corbet G B, Hill J E. The mammals of the Indomalayan region. Oxford University Press; United States: 1992. 488. [Google Scholar]
- Cranbrook E, Edwards D S. A tropical rainforest: the nature of biodiversity in Borneo at Belalong. Brunei Sun Tree Publishing; London UK and Singapore: 1994. 38. [Google Scholar]
- Francis C M, Hill J E. A review of the Bornean Pipistrellus (Mammalia: Chiroptera) Mammalia . 1986;50(1):43–56. doi: 10.1515/mamm.1986.50.1.43. [DOI] [Google Scholar]
- Francis C M. A field guide to the mammals of South-East Asia. New Holland; London: 2008. 39. [Google Scholar]
- Görföl T, Kingston T, Hutson A M, Francis C M. Hypsugovordermanni . The IUCN Red List of Threatened Species 2016. 2016 doi: 10.2305/IUCN.UK.2016-3.RLTS.T44195A22127778.en. [DOI]
- Hill J E. Bats (Mammalia: Chiroptera) from Indo-Australia. Bulletin of the British Museum (Natural History) Zoology. 1983;45:103–208. doi: 10.5962/p.27997. [DOI] [Google Scholar]
- Horáček I, Hanák V. Generic status of Pipistrellus savii and comments on classification of the genus Pipistrellus (Chiroptera, Vespertilionidae. Myotis . 1986;23-24:9–16. [Google Scholar]
- Lim L S, Csorba G, Wong C M, Zubaid A, Rahman S P H, Jayaraj V K, Anwarali Khan F A, Huang C C J, Najimudin N, Görföl T. The systematic position of Hypsugomacrotis (Chiroptera: Vespertilionidae) and a new record from Peninsular Malaysia. Zootaxa. 2016;4170(1):169–177. doi: 10.11646/zootaxa.4170.1.10. [DOI] [PubMed] [Google Scholar]
- Nash S V, Nash A D. WWF/IUCN Conservation for Development Program in Indonesia. Directorate General of Forest Protection and Nature Conservation, Bogor; 1987. Management considerations for the Tanjung Puting National Park, Central Kalimantan, Indonesia. 21 pp. [Google Scholar]
- Nor S M. The mammalian faunda on the islands at the northern tip of Sabah (Banggi and Balembangan) Fieldiana: Zoology. 1996;83:1–51. [Google Scholar]
- Payne J, Francis C M, Phillipps K. A field guide to the mammals of Borneo. The Sabah Society; Kota Kinabalu: 1985. 33. [Google Scholar]
- Phillipps Q, Phillipps K. Phillipps' field guide to the mammals of Borneo: Sabah, Sarawak, Brunei and Kalimantan. 2nd. Natural History Publications (Borneo); Kota Kinabalu: 2018. 40. [Google Scholar]
- Rydell J, Fenton M B, Seamark E, Webala P W, Michaelsen T C. White and clear wings in bats (Chiroptera) Canadian Journal of Zoology. 2020;98(2) doi: 10.1139/cjz-2019-0182. [DOI] [Google Scholar]


