Physical Description

Source: Malaysian Bat Education Adventure

Conservation Status File:IUCN Conservation Status - Least Concern.png

Scientific Classification Kingdom: Animalia Phylum:--- Chordata Class:------- Mammalia Order:-------- Chiroptera Family:-------- Vespertillionidae Genus:--------- Kerivoula Species:-------- Kerivoula pellucida (Waterhouse, 1845)

The clear-winged woolly bat (Kerivoula pellucida) is a small mammal, with an average forearm of around 31 millimeters (mm) and an average weight of approximately 4.5 grams..less than that of a U.S.nickel coin!.

The wing membrane is very pale greyish brown, and is unique among the Kerivoula because they are translucent, meaning light passes through them. It is even possible to read print through the membrane! This is how this species gets its name, because pellucida comes from the latin word for transparent, “pellucidus”. The wings are relatively large and rounded, and such a light fluffy body on so big a wing area enables the bat to fly very slowly and avoid obstacles even in the densest parts of the forest. In fact, K. pellucida is probably the most manoevrable bat in the whole reserve.

Like all of the Kerivoula, or woolly bats, Kerivoula pellucida has long fluffy fur, which in this species is a light buffy-brown color with pale bases to the hairs.

The ears are large and funnel-shaped, another characteristic of the Kerivoula, and in this species they are darker at the edges and paler at the base. The tragus, inside the ear, is very long and pointed, and pale like the ear base.  The nose is simple, but the face and sometimes the ears are often a pinkish yellow color.

The tail is very long and the tail membrane large. The bat uses this tail membrane partly to help it brake during flight, but it also acts as a sort of scoop that helps the bat to catch insects.

Interestingly, adult males often have a gland near the end of the tail. But so far we don’t know what its function is.

Distribution

Source: Malaysian Bat Education Adventure

This species is found in Peninsular Malaysia, Sumatra, Java, Borneo and the Philippines

Habitat

They are thought to be found chiefly in the forest understory.

Food and Feeding Habits

This insect-eating bat catches its prey on the wing, using an echolocation call that sweeps from a very high frequency (178 kHz) to a much lower one (58 kHz), and is repeated extremely rapidly. Its wing shape is perfect for a high degree of control in flight, making the bat relatively slow but highly manoeuvrable amongst the vegetation.

Behavior

The Clear-winged wooly bat is relatively common in the understorey.  It has been found roosting in dead curled banana leaves and foraging in the upperstorey of tall forests. In Krau Wildlife Reserve in Malaysia, an individual followed on release roosted in a cluster of dead leaves in the understorey with other individuals. This is a very social species: individuals captured in harp traps frequently roost in tight clusters, and they will fly together when released. Although we can’t hear them without a bat detector, they often produce special calls called “contact” calls while they are flying. These are different from their echolocation calls and probably enable members of a group to keep in touch as they are foraging.

Reproduction

Breeding occurs all year round and, like most bat species, the mother gives birth to a single pup, which weighs around a quarter of her weight. At the beginning of its life, the pup clings to its mother's belly as she forages but is soon able to fly alongside her and catch its own prey. After just one year, the young clear-winged woolly bats are able to breed.

Threats

Deforestation and forest fragmentation pose the greatest threat to the Clear-winged woolly bat. The rapid increase in land devoted to commodity agriculture (such as cocoa, coffee, oil palm, rice and rubber) has resulted in extensive loss of forest in the last 20 years. In recent years, one of the largest agricultural drivers of deforestation in Malaysia, Sumatra and Thailand has been oil palm. Together, Malaysia and Indonesia export 88 percent of the world's palm oil, for use in products such as margarine, lipstick and detergent. In addition, despite the contribution of many bats in the control of insect crop pests, persecution of bats is also a threat.

Conservation Status

This species has been classified as Lower Risk / Least Concern (LR/lc) on the IUCN Red List.

References and Further Reading

• Kerivoula pellucida (Waterhouse, 1845) EOL accessed June 23, 2012.
• Kerivoula pellucida Malaysian Bat Education Adventure (includes video)