Fig 1
Fig 2
Fig 3
Fig 4
Fig 5
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Order : CHIROPTERA
Family : Rhinolophidae
Species : Rhinolophus trifoliatus
Forearm Length : up to 5.7 cm
Weight : up to 20 grams
Rhinolophus
trifoliatus (Trefoil Horseshoe
Bat) inhabits a range of lowland forest types including primary, secondary
and mangrove. It is not suited to heavily disturbed, open habitats such as
plantations, agricultural areas or grassland.
It feeds on a variety of flying insects which it detects by
echolocation whilst hanging from a perch, before swooping down to catch
its prey. Its wings have a "low wing loading", which are characteristic of
bats which utilise slow, but agile, flight amongst dense vegetation
(Pottie et al, 2005).
Individuals of this species roost alone, typically suspended no more than
3 metres from the forest floor on small trees and vines, or beneath palms.
A number of favoured roosts may be used within the home range of the
individual (Kingston et al, 2006).
This is one of the most easily identifiable of small, insectivorous bats :
its yellow noseleaf is not seen in other species in the region. Its ears
are relatively large, and these may also be yellow. Its fur is grizzled
greyish brown and its wings are reddish brown.
The Trefoil Horseshoe Bat occurs in parts of India, Myanmar, southern
Thailand, Peninsular Malaysia, Singapore, Sumatra, Riau Archipelago, Java
and other, smaller islands of western Indonesia.
Fig 1 : Typical perching posture, with wings folded across the belly and
head arched forward. From this position it is easy for the bat to swoop onto
passing insects.
Fig 2: Daytime roosting posture with head tucked beneath the wings.
Figs 3 and 4 : Close-ups of the complex noseleaf and ears. The eyes are
tiny, and are not even visible in Fig 4.
(Figs 1 to 4 are of the
same specimen from freshwater swamp forest habitat in Singapore).
Fig 5 : Suspended from a slender branch whilst consuming an insect.
The branch is used as a perch from which the bat echolocates and swoops down
to intercept flying insects. Seen at Taiping, Perak, Peninsular
Malaysia.
Fig 6 : Adult with large juvenile, in Singapore's
central forests. Photo thanks to Tony O'Dempsey
References :
Kingston, T., Lim B.L., Zubaid, A., 2006. Bats of Krau Wildlife Reserve. Universiti Kebangsaan Malaysia.
Pottie, S. A., Lane, D.
J., Kingston, T., & Lee, B. P. Y. H. (2005). The microchiropteran bat fauna
of Singapore. Acta Chiropterologica, 7(2), 237-247.
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