Lesser Sheath Tailed Bat

Little information is available regarding predators of lesser sheath-tailed bats.

Lesser sheath-tailed bats have very smooth and shiny fur that ranges from dark to reddish brown. Their underside is brown and wings are black. They have triangular shaped ears, large eyes and a pointed, simple nose that has no noseleaf. A short tail protrudes from the membrane between the legs, and, when the legs are stretched, the tail is retracted in a membrane (uropatagium) and unseen. When the wings of lesser sheath-tailed bats are relaxed, they have an extra fold that distinguishes them from other bat families. This species can fly straight and fast due to the shape of their bodies, allowing them to follow gaps formed by streams or paths in the forest. The forearm is generally 43 to 45 mm in length. The dental formula is (i 2/3, c 1/1, pm 2/2, m 3/3) x 2 = 34. g. Emballonura are the only genera in the family to have two pairs of upper incisors. A "W" pattern of cusps and ridges is also found in their molars.

Range mass: 4 to 5 g.

Range length: 40 to 45 mm.

Range wingspan: 26.1 to 26.58 cm.

Other Physical Features: endothermic ; bilateral symmetry

Little information is available regarding the lifespan of lesser sheath-tailed bats.

Lesser sheath-tailed bats are often found in areas of lowland forest and subtropical/tropical moist areas, primarily up to 1800 m. This species roosts in caves and cave entrances, rock crevices, large tree holes, and forests. They can be found in smaller numbers hanging under tables and buttresses in lowland forest Malaysia, hanging rock in tropical lowland forests and manmade caves in Thailand.

Range elevation: 1800 (high) m.

Habitat Regions: tropical ; terrestrial

Terrestrial Biomes: forest ; rainforest

Other Habitat Features: caves

Because of continued demand for palm oil, which is used in margarine, lipstick, and detergent, deforestation is continuing in prime habitat of lesser sheath-tailed bats. Malaysia and Indonesia together contribute about 88% of the world's palm oil. Large retailers, including Migros, Switzerland's largest retail chain, have expressed their concern for the destruction of these habitats due to palm oil production. Migros has recently ensured all of their products made of palm oil will not contribute to deforestation.

Lesser sheath-tailed bats have a very distinct echolocation call lasting 6 to 8 milliseconds. Each call consists of a short sweep up in the frequency range, then a steady constant frequency staying between 48 and 51 kHz. The call finishes with a sweep down through its frequency range. Emballonura monticola studied in Singapore were recorded as having a maximum frequency of 49.3 kHz and a minimum frequency of 46.0 kHz.

Communication Channels: acoustic

Perception Channels: tactile ; acoustic ; ultrasound ; echolocation ; chemical

Lesser sheath-tailed bats are declining in population but are still considered of Least Concern on the IUCN Red List because of their location. Most members of this species are currently located within protected areas, and populations are decreasing at a rate that ranks them as non-threatened. Increased deforestation from illegal logging and forest fires as well as destruction of caves due to limestone extraction are of increasing concern. Both scientific groups and retailers are promoting educational programs to raise awareness

US Federal List: no special status

CITES: no special status

IUCN Red List of Threatened Species: least concern

No information known.

Many bats, including lesser sheath-tailed bats, contribute to the control of insect pests on crops.

Positive Impacts: controls pest population

As insectivores, lesser sheath-tailed bats may regulate insect populations. Because lesser sheath-tailed bats occasionally eat fruit, they may contribute to seed dispersal.

Ecosystem Impact: disperses seeds

Lesser sheath-tailed bats primarily hunt insects in dense forests. They have also been observed during the day in dense shade foraging for insects. This species has also occasionally been observed eating fruit.

Animal Foods: insects

Plant Foods: fruit

Primary Diet: carnivore (Insectivore )

Lesser sheath-tailed bats can be found in the Malay Peninsula and the surrounding areas, including some offshore islands.

Biogeographic Regions: oriental (Native )

Lesser sheath-tailed bats are believed to be polygynous, though little information is available regarding the mating systems of this species.

Mating System: polygynous

Lesser sheath-tailed bats have two breeding seasons per year, the first in February through March and the second in October through November. During each birth period, females give birth to a single offspring. The pup weighs about a quarter of the mother's weight.

Breeding interval: Lesser sheath-tailed bats have two breeding seasons per year

Breeding season: Mating of lesser sheath-tailed bats occurs in February-March and in October-November

Average number of offspring: 1.

Average time to independence: 1 years.

Average age at sexual or reproductive maturity (female): 1 years.

Average age at sexual or reproductive maturity (male): 1 years.

Key Reproductive Features: seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual

Female lesser sheath-tailed bats scoop their pups to their body with their wings as soon as a pup is born, preventing it from falling. The pup clings to its mother's body while she forages until the pup becomes too heavy to carry. Soon after weaning, usually within a year, the pup becomes a mature adult.

Parental Investment: female parental care ; pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female); pre-independence (Provisioning: Female, Protecting: Female)

The echolocation calls of this delicate bat are extremely distinctive, starting with a short sweep up the frequency range, followed by a steady constant frequency component between 48 and 51 kHz, and finishing with a final sweep down through the frequency range. Each call lasts just 6 – 8 milliseconds (6). The lesser sheath-tailed bat uses these calls to orientate itself in the forest, and to detect small insects to feed upon, by waiting for the returning echo of the call and building up a detailed picture of its environment. It is thought that the lesser sheath-tailed bat has two breeding seasons each year; one in February and March, and the second in October and November. However, individuals have also been found to be pregnant at other times of year (2). Each female gives birth to a single pup, which she prevents from falling to the floor of the roost by scooping it to her body with her wing. At birth, the pup weighs a quarter of its mother's weight (this is normal in bats, but extraordinary in much of the rest of the mammalian class). The mother will forage with her pup clinging to her belly until it becomes too heavy to carry. Soon afterwards the pup is weaned, and within a year it will become a mature adult (7).

Deforestation of primary forest for oil palm plantations, including within protected areas, is an issue of major concern and one that relies on both governmental action and consumer concern. Some large retailers have agreed, in collaboration with the WWF, to source products containing palm oil from plantations that are not on deforested land (8). Many scientific and charitable groups contribute to bat monitoring and local education programmes that can help to reduce persecution and raise awareness of the natural assets of the land (7).

The angular features of this small and timid bat make it easy to recognise. It has a pointy, simple nose with no noseleaf, large black eyes, and triangular ears. The fur is extremely smooth and shiny, varying in colour from reddish brown to dark brown, and fading to buffy brown on the underside. In common with other members of the Emballonuridae, or sheath-tailed bats, the lesser sheath-tailed bat has a short tail that protrudes from the interfemoral membrane between the legs, unless the legs are stretched, when the tail retracts into its sheath (3). The wings are black, and so long that when at rest, they have one more fold than those in other bat families (4). Their shape means that the bat can fly fast and straight in forest gaps, such as over streams (3).

With a body and wings adapted to foraging in forest gaps, the lesser sheath-tailed bat is found above streams and around tree falls where it can take advantage of its high speed, but poor in-flight agility. It is found in primary rainforest up to 1800 m, where it roosts in groups in large tree holes, rock crevices and at cave entrances. Each bat positions itself flat against the wall of its roost, using a forearm to prop itself up (2) (3), and will remain alert when roosting (4).

The lesser sheath-tailed bat is found in southern Burma, Thailand, Peninsular Malaysia, Sumatra, Java, Borneo, southern Sulawesi, and many offshore islands (5).

Classified as Lower Risk – least concern (LR/lc) on the IUCN Red List 2004 (1).

The rapid increase in land devoted to growing oil palm has resulted in extensive loss of primary forest. Together, Malaysia and Indonesia export 88% of the world's palm oil, for use in products such as margarine, lipstick and detergent. Deforestation continues at a steady rate for conversion to agricultural land and building communities, and despite the contribution of many bats in the control of insect crop pests, persecution of bats is also a threat (8).

The lesser sheath-tailed bat (Emballonura monticola) is a species of sac-winged bat in the family Emballonuridae. It is found in the Malay Peninsula (including Myanmar and Thailand), Borneo, and many other parts of the Indonesian Archipelago including Sulawesi, Java, and Sumatra.