Fig 1
Fig 2
Fig 3
Fig 4
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Order : CHIROPTERA
Family : Hipposideridae
Species : Hipposideros bicolor
Forearm Length : 4.5 to 4.9 cm
Weight : up to 11 grams
(Source: Douangboubpha et al, 2010)
Hipposideros bicolor
(Bicoloured Roundleaf
Bat) is a small species of roundleaf bat which occurs in many parts of Southeast
Asia, mainly in lowland primary and good secondary forest, and adjacent
plantations and wooded rural areas.
It roosts in a variety of settings including caves, tunnels and rock
crevices.
Some
roosts in Thailand contain large numbers of individuals.
The diet of this small bat would comprise tiny flying insects. The constant frequency (CF) portion of its search phase
call, when hunting for prey, has a peak frequency of around 131 kHz.
The example shown here was photographed at dusk as it flew from an area of
degraded lowland primary forest to an adjacent patch of regenerated secondary
forest, presumably to forage for insects. All three images are believed to be of the same individual.
Constant frequency (CF) calls of between 130.5 and 131.4 kHz were detected.
In photographs, Hipposideros bicolor
can be tentatively identified by its fur colour; individual hairs are pale or whitish at the base
and darker at the extremity. The hairs on its back have dark brown tips, and
those on the belly have buffy tips. Some specimens, however, may be bright
orange all over.
The shape of
the noseleaf also aids in photographic identification; this species has 'one pair of
rudimentary supplementary lateral leaflets' (Douangboubpha et al, 2010). The ears are large and rounded.
Bats using the name Hipposideros bicolor have long been known to
comprise a species complex, but some cryptic forms are now recognised as unique
species. For example, in 2010 Hipposideros
atrox was described (Douangboubpha et al, 2010); earlier this bat
was separated from Hipposideros bicolor on the basis of a different
echolocation call of 142 kHz (Kingston et al, 2006).
Within Peninsular Malaysia, Hipposideros
atrox is now designated as Hipposideros
kunzi (Kunz's Roundleaf Bat) (Murray et al, 2018).
Hipposideros bicolor occurs in parts of
Thailand, Peninsular Malaysia, Singapore, Sumatra, Java, Borneo, Timor-Leste
and a few locales in the Philippines.
Figs 1 to 3 : Images from Perak, Peninsular Malaysia at the edge of degraded
lowland primary forest; constant frequency (CF) calls of 130.5 to 131.4 kHz
were detected as these bats flew past. Based on their fur colour, all three images are believed to be of the same bat.
Fig 4 : Sonogram recorded during the flypass of the bat in Figure 1; the constant frequency (CF)
component averages 131.4 kHz.
References :
Douangboubpha, B., Bumrungsri, S., Soisook, P., Satasook, C., Thomas, N. M. & Bates, P. J. (2010). A taxonomic review of the
Hipposideros bicolor species complex and H. pomona
(Chiroptera: Hipposideridae) in Thailand. Acta Chiropterologica, 12(2),
415-438.
Kingston, T., Lim B.L., Zubaid, A., 2006. Bats of Krau Wildlife
Reserve. Universiti Kebangsaan Malaysia.
Murray, S. W., Khan, F. A., Kingston, T., Zubaid, A., & Campbell, P.
(2018). A new species in the Hipposideros bicolor group (Chiroptera:
Hipposideridae) from Peninsular Malaysia. Acta chiropterologica, 20(1),
1-29.
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