Murina suilla
brown tube-nosed bat

Murina suilla is found on the mainland and nearby islands of southeastern Asia. Its range includes the Malay Peninsula and the islands of Borneo, Sumatra, Java Nias and other smaller nearby islands. There are reports of this species from Sulawesi, the Peleng Islands, and New Guinea but they are outside of the accepted current distribution and are disputed. (Nowak, 1999; Wilson and Reeder, 2006)

Brown tube-nosed bats are found in hilly areas of Southeast Asia. They may prefer areas near cultivated or grassy fields where they have been seen flying low, just over the tops of crops. Analysis of M. suilla echolocation calls suggest that they are well adapted to detecting insects in the highly cluttered forests of Southeast Asia. Members of the genus Murina have also been detected roosting in leaf litter, caves, and trees. They rarely found in habitats above 1000 meters. ("Biodiversity Information Sharing Service (BISS)", 2006; Kingston et al., 1999; Kleiman, Geist, and McDade, 2004)

Murina suilla has an average length of 3.3 to 6.0 cm with an average forearm length of 2.6 to 4.5 cm. The average weight of these bats is 3 to 5 grams. Brown tube-nosed bats have dark grayish brown fur. The underside of M. suilla is whitish and the flight membrane is brown. Polymorphism is not noted in this species. The entire family Vespertilionidae is generally known for its lack of nose ornaments and for a well developed tragus going to the base of the ear. The genus Murina is known for their tube-like nostrils. (Kleiman, Geist, and McDade, 2004; Nowak, 1999)

There is no information on the lifespan of this species.

Murina suilla has been observed flying low over crops and grasslands. Echolocation call characteristics suggest that it would be well suited to detect insects among foliage in dense forests. Other members of the genus Murina have been known to use leaf litter of cardamom plants and caves as roosting sites. (Kingston et al., 1999; Nowak, 1999)

Home Range

There is no information about the home range of brown tube-nosed bats.

Brown tube-nosed bats primarily navigate through the use of echolocation but also detect visual cues. Murina suilla has a broad range of calls which helps these bats navigate through dense forest environments and catch prey in flight. Brown tube-nosed bats begin their echolocation calls with a frequency of about 165 kHz and end their calls with a frequency of about 55.2 kHz. These short calls of about 2 milliseconds may have reduced the need for visual cues when hunting and may have led to a reduction in the use of eyes in this species. Modes of communication are not well-understood in Murina species. Like most mammals they probably use chemical, tactile, and auditory cues in communication. (Kingston et al., 1999)

The use of echolocation and the tooth morphology of M. suilla suggests that it is insectivorous. In addition, analysis of the calls used in echolocation by M. suilla suggests that these bats are adept at detecting insects in cluttered habitats. Brown tube-nosed bats are also quite maneuverable, which would be helpful for catching insects in flight. There is little information about the specific insects that are captured. (Kingston et al., 1999; Kleiman, Geist, and McDade, 2004)

Because bats are both nocturnal and capable of flight, they avoid predation by many predators. However owls hunt bats at night and climbing snakes may prey on roosting bats. (Kleiman, Geist, and McDade, 2004)

Brown tube-nosed bats feed on insects and may play a role in keeping insect populations in check. The impact on insect numbers is difficult to determine because it may be underepresented due to biases in censusing methods. Mist nets which have been used in the past are usually avoided by these maneuverable bats. Harp traps are more efficient at catching brown tube-nosed bats. Future censusing using harp nets would better demonstrate the effect that M. suilla has on its ecosystem. (Kingston et al., 1999; Kleiman, Geist, and McDade, 2004)

No negative impacts have been documented, although bat species are sometimes implicated in the transmission of rabies and other diseases.

Humans benefit from M. suilla from its diet of insects. This may be important for protecting agricultural crops and reducing threats of insect borne pathogens. The full effect of brown tube-nosed bats on insect populations may be underepresented due to census bias. (Kingston et al., 1999; Kleiman, Geist, and McDade, 2004)

Murina suilla appears to be at low risk of extinction. Habitat degradation is one of the factors which have been causing declines in populations of other bat species in the area. Oil palm plantation growth may pose a future threat to the species. ("Biodiversity Information Sharing Service (BISS)", 2006; Wilson and Reeder, 2006)

Murina suilla includes the synonymous names Murina balstoni Thomas 1908 and Murina canescens Thomas 1923. There are many common names for M. suilla including brown murine bats, and lesser tube-nosed bats. ("Biodiversity Information Sharing Service (BISS)", 2006; Nowak, 1999; Wilson and Reeder, 2006)