Order : CHIROPTERA
Family : Emballonuridae
Species : Emballonura monticola

Forearm Length : up to 4.5 cm
Weight : up to 5.5 grams

The genus Emballonura comprises eight species of sheath-tailed bat which occur in Southeast Asia, eastern Indonesia, Papua New Guinea and islands of the western Pacific Ocean.

Sheath-tailed bats are so-called because of their short tail which protrudes from the interfemoral membrane connecting their hind legs; when the legs are stretched out the tail disappears into the sheath.

Emballonura monticola (Lesser Sheath-tailed Bat) is the smallest of the eight species, typically weighing around 5.5 grams.

This small bat roosts near cave entrances, in rock crevices or under rock overhangs, in large tree holes and beneath the buttresses of fallen trees. Some roosts, especially under rock overhangs, may be well lit by day. If a roost is accidentally disturbed, an audible click can be heard which alerts other bats to the presence of an intruder.

Its fur colour is dark to reddish-brown, and its wings are long and narrow. Its ears are triangular-shaped, its muzzle is simple in form and its eyes are relatively large.

Emballonura monticola is a widespread inhabitant of lowland forest in the Malay Peninsula (comprising southern Thailand, southern Myanmar, Peninsular Malaysia and Singapore) and the islands of Sumatra, Java, Borneo and Sulawesi. In Singapore it is now very rare.

Fig 1 : Roosting beneath a large sandstone boulder by day.

Fig 2 : A colony of Lesser Sheath-tailed Bat roost under this rocky outcrop, used as a Buddhist shrine in Panti Forest, Johor, Peninsular Malaysia..

Fig 3 : This roost has more than 20 individuals.

Figs 4 and 5 : Two examples from Johor, Peninsular Malaysia with a roost posture that is typical of the species.

Fig 6 : Example in a boulder roost on Penang Island, Peninsular Malaysia.

Fig 7 : Example roosting beneath a large granite boulder near a fast-flowing mountain stream near Ipoh, Perak, Peninsular Malaysia.

Fig 8 : The ultrasonic call of Emballonura monticola is easily identified; it comprises a typical hump-shaped call of around 8 milliseconds, at a frequency of around 50 kHz, with multiple harmonics.


References :

Francis, C.M. 2019. A Field Guide to the Mammals of South-east Asia. Second Edition.  New Holland. 416 pp.

Kingston, T., Lim B.L., Zubaid, A., 2006. Bats of Krau Wildlife Reserve. Universiti Kebangsaan Malaysia.