Large false serotine (Hesperoptenus tomesi)

Also known as: Tomes’ false serotine
GenusHesperoptenus (1)
SizeMale head-body length: 7.4 cm (2)
Female head-body length: 8.3 cm (3)
Tail length: 4.4 - 5.3 cm (3) (4)
Weightc. 33.3 g (3)

The large false serotine is classified as Vulnerable (VU) on the IUCN Red List (1).

The large false serotine (Hesperoptenus tomesi) was named in 1905 in honour of the zoologist R.F. Tomes, who was the first person to recognise the large false serotine as a new species (2).

This species has close, fine dark brown hair all over its body (2). It can be easily mistaken for other species in its genus, but it is distinguished by its large, rounded head and sloping forehead (3). In general, it is larger than other Hesperoptenus species and has bigger teeth, particularly the first upper incisor (2). The ears of the large false serotine are short and rounded, with a hatchet-shaped tragus (3).

When young large false serotines are born, they are naked and blind. Once they have developed, females tend to be larger than males (5).

The large false serotine is found in South East Asia. It was originally discovered in Malaysia, close to the city of Malacca (2), but has since been recorded in other areas of Peninsular Malaysia, as well as Sabah and Sarawak in Borneo (1). More recently, the first reported sighting of this species in Thailand was recorded (6).

All reports of the large false serotine have come from forest habitats in lowland areas (1). In Borneo, it has been found in lowland dipterocarp forest (4), and in lowland primary forest in Peninsular Malaysia (1). It has been recorded in lower evergreen montane forest in Thailand (6).

Like many other bat species, the large false serotine is insectivorous (5), and has been observed flying low over forest streams in search of insects (4). It uses a piece of skin between the feet (the interfemoral membrane) to catch insects while flying, and it holds them there until it lands (2).

Little is known about the reproductive behaviour of the large false serotine, but Hesperoptenus species typically give birth to a single young. This species lives either on its own, or in small mixed sex groups in the top of trees, and stays there throughout the day. In the evening, the large false serotine begins to search for insects within its territory, and if there is little food it will chase others of the same species away (7). Like other Hesperoptenus species, the large false serotine uses echolocation to search for its prey and navigate its surroundings (8).

The continuing decrease in population of the large false serotine is due to the destruction of its forest habitat (1), with the main causes of habitat destruction being logging, urban development and forest fires, especially in lowland areas (9).

In the forests of Sarawak and Sabah, which is a crucial habitat for the large false serotine, 19,340 square kilometres of forest were lost between 1990 and 2005, and these losses continue (10). The logging of dipterocarp forest in Borneo is also of particular concern. These trees provide large amounts of timber for world trade, but they also provide important habitat for the large false serotine and many other South East Asian species (9).

The large false serotine is known to occur in protected areas, such as the Sapagaya Forest Reserve and the Tabin Wildlife Reserve in Sabah, Malaysia (1). Its only record in Thailand is also from a protected area, the Kangkachan Nature Reserve (6).

Logging will continue to be a problem for the large false serotine, particularly of dipterocarp forest. Suggested conservation measures include the sustainable management of forests, which would help to conserve the large false serotine and other threatened forest species. Sustainable logging will also benefit humans, as it ensures timber production for the future while preserving biodiversity (9).

Very little is known about the distribution and biology of the large false serotine, and as with other species more research is needed in order to better understand how to conserve it. This would lead to the best possible “Species Action Plan” for its conservation (11). In the past the most successful bat conservation projects have worked with a long term view of the species and its habitat. Support of local people and the government is also crucial in any conservation programme (10). 

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  1. IUCN Red List (November, 2011)
  2. Thomas, O. (1905) A new genus and two new species of bats. The Annals and Magazine of Natural History, 16: 572-576.
  3. Khan, F.A.A. (2008) Diversification of Old World Bats in Malaysia: An Evolutionary and Phylogeography Hypothesis Tested through the Genetic Species Concept. MSc Thesis, Texas Tech University, US.
  4. Payne, J.C.M., Francis, C.M. and Phillipps, K. (1985) A Field Guide to the Mammals of Borneo. The Sabah Society, Kota Kinabalu, Malaysia.
  5. Hayssen, V.D., Tienhoven, A.V., Tienhoven, A.V. and Asdell, S.A. (1993) Asdell’s Patterns of Mammalian Reproduction: A Compendium of Species-Specific Data. Cornell University Press, New York.
  6. Bumrungsri, S., Harrision, D.L., Satasook, C., Prajukjitr, A., Thong-Aree, S. and Bates, P.J.J. (2006) A review of bat research in Thailand with eight new species records for the country. Acta Chiropterologica, 8(2): 325-359.
  7. Nowak, R.M. (1991) Walker’s Mammals of the World. The Johns Hopkins University Press, Baltimore and London.
  8. Kingston, T., Jones, G., Akbar, Z. and Kunz, T.H. (2003) Alternation of echolocation calls in five species of aerial feeding, insectivorous bats from Malaysia. Journal of Mammology, 84(1): 205-215.
  9. Sodhi, N.S.and Brook, B. W. (2006) Southeast Asian Biodiversity in Crisis. Cambridge University Press, Cambridge.
  10. Fleming, T.A. and Racey, P.A. (2009) Island Bats: Evolution, Ecology and Conservation. University of Chicago Press, Chicago.
  11. Hutson, A.M., Mickleburgh, S.P. and Racey, P.A. (2001) Microchiropteran Bats: Global Status Survey and Conservation Action Plan. IUCN, Gland, Switzerland and Cambridge, UK.