Tylonycteris pachypus
lesser bamboo bat

Lesser bamboo bats, Tylonycteris pachypus, are found in Bangladesh, India, Myanmar, South China, Thailand, Laos, Cambodia, Vietnam to peninsular Malaysia, the Philippines, Sumatra, Java, Borneo, Bali (Indonesia) and the Andaman Islands (India). (Zhang, et al., 2006)

Lesser bamboo bats occupy lowland agricultural areas that contain bamboo stands. In a study done by Zhang et al. (2006), lesser bamboo bats were observed in three habitat types: along trees and houses, pathways along bamboo forest, and above bamboo forest. Of 145 individuals caught over a 28 day period, 45 % were collected on the pathway, 52 % were collected along the trees and houses and 3 % were collected above the bamboo forest. (Zhang, et al., 2006)

Lesser bamboo bats are small bats with well developed tails that are completely enclosed in a tail membrane. (Medway and Marhsall, 1970)

Mating systems in lesser bamboo bats are not known, although polygyny is suspected based on some observed roosting patterns. (Zhang, et al., 2005)

Mating seems to be seasonal, with males being fertile from mid-October to mid-January and females are in estrous from mid-October to mid-November. One offspring is usually born, sometimes two. Gestation is from 12 to 13 weeks long and the young are nursed for 5 to 6 weeks after that. The young are independent immediately after weaning and can breed in the first year after their birth. (Zhang, et al., 2006)

Mothers care for their young on their own. Because they roost in groups, they need efficient and distinctive communication calls to ensure successful reunions. In T. pachypus, recognition between the mother and pup is mutual. Recognition involves visual, acoustic and olfactory cues. Vocal signals that mediate recognition can be the mother’s echolocation calls, isolation calls from the infant, or other communication calls from the mother or infant. Infant bats often emit distinctive isolation calls (i-calls) which assist the location of offspring by the mother. (Zhang, et al., 2005)

The lifespan of T. pachypus is not reported. Like other vespertilionids, they may have relatively long lifespans, given their body size.

In lesser bamboo bats the sexes display 2 different roosting behaviors. Males are solitary and females are gregarious. In some roosting sites, a single male, twelve adult females and 24 infants were found. Lesser bamboo bats are active at night and roost during the day.

Home range size in lesser bamboo bats is not known.

Vocalization from infants occurred for precursor for echolocation calls and as isolation calls (i-calls) to attract the mother. As the infants grew older the 2 calls increased. Female directive calls are different than their infants calls by having lower frequency and longer duration. (Zhang, et al., 2005)

Lesser bamboo bats also use their vision, sense of smell, and sense of touch to perceive their environment and to communicate effectively among individuals.

Lesser bamboo bats are strictly insectivorous. The diet consists primarily of 7 different orders of insects. Hymenoptera, Diptera, Coleoptera, and Hemiptera are the 4 main orders, making up 62.3 %, 29.6 %, 6.0%, and 1.5%, respectively, of their diets. Other insects eaten include Homoptera, Blattodea, and Embioptera. Swarming termites, Isoptera, are also a small portion of their diet. Seasonal variation from spring to autumn occurs in their diet, no order of insects made up more than 50% of the total diet from March to April. From May to October, Hymenoptera made up more than 50% of the diet by volume. (Zhang, et al., 2005)

Predation on these bats is rare, but they have been known to be preyed on by owls when foraging at night. (Lewis, 1995)

Lesser bamboo bats keep insect pest populations down by eating thousands of them each night. Some of these insects are considered pests because they will destroy agricultural fields. Bamboo Gigantochloa scortechinii is used for roosting. Basilia hispida, a bat fly, is an ectoparasite of T. pachypus. (Marshall, 1971)

Humans benefit from T. pachypus through their control of insect populations. They can eat thousands of insects a night. (Marshall, 1971)

There are no known adverse effects of T. pachypus on humans.

Lesser bamboo rats are considered lower risk/least concern by the IUCN. Populations seem stable currently.