The lesser bamboo bat or lesser flat-headed bat (''Tylonycteris pachypus'') is one of the smallest species of

vesper bat Vespertilionidae is a family of microbats, of the order Chiroptera, flying, insect-eating mammals variously described as the common, vesper, or simple nosed bats. The vespertilionid family is the most diverse and widely distributed of bat famili ...

, and is native to Southeast Asia.

Description

The bat, the size of a

bumble bee A bumblebee (or bumble bee, bumble-bee, or humble-bee) is any of over 250 species in the genus ''Bombus'', part of Apidae, one of the bee families. This genus is the only extant group in the tribe Bombini, though a few extinct related genera ...

, is among the smallest mammals on earth,Smithsonian Institution
/ref> measuring about in head-body length with a tail about long and a wingspan of . Adults weigh between . The fur ranges from golden or cinnamon to dark brown, and is paler on the underside of the body. The head is flattened, with a short snout and triangular ears with a wide tragus. The name ''pachypus'' means "thick-footed" and refers to the presence of smooth fleshy pads at the base of the thumb and on the heels of the feet, which help the bat grip onto bamboo stalks. The wings have an

aspect ratio The aspect ratio of a geometry, geometric shape is the ratio of its sizes in different dimensions. For example, the aspect ratio of a rectangle is the ratio of its longer side to its shorter side—the ratio of width to height, when the rectangl ...

of 6.2, allowing the bat to be agile in flight at the expense of a slow speed. A 4.8 gram T. pachypus has about an 80 mg brain.

Distribution and habitat

Lesser bamboo bats are found throughout

Southeast Asia Southeast Asia is the geographical United Nations geoscheme for Asia#South-eastern Asia, southeastern region of Asia, consisting of the regions that are situated south of China, east of the Indian subcontinent, and northwest of the Mainland Au ...

from

Bangladesh Bangladesh, officially the People's Republic of Bangladesh, is a country in South Asia. It is the List of countries and dependencies by population, eighth-most populous country in the world and among the List of countries and dependencies by ...

to southern

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

and

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania, between the Indian Ocean, Indian and Pacific Ocean, Pacific oceans. Comprising over List of islands of Indonesia, 17,000 islands, including Sumatra, ...

and also in southern and eastern

India India, officially the Republic of India, is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area; the List of countries by population (United Nations), most populous country since ...

. It inhabits deciduous forests with extensive areas of bamboo growth, at altitudes from sea level to . Five subspecies are recognised: * ''Tylonycteris pachypus aurex'' - India and Bangladesh * ''Tylonycteris pachypus bhaktii'' -

Lombok Lombok, is an island in West Nusa Tenggara province, Indonesia. It forms part of the chain of the Lesser Sunda Islands, with the Lombok Strait separating it from Bali to the west and the Alas Strait between it and Sumbawa to the east. It is rou ...

* ''Tylonycteris pachypus fulvidus'' - China,

Indochina Mainland Southeast Asia (historically known as Indochina and the Indochinese Peninsula) is the continental portion of Southeast Asia. It lies east of the Indian subcontinent and south of Mainland China and is bordered by the Indian Ocean to th ...

* ''Tylonycteris pachypus meyeri'' -

Philippines The Philippines, officially the Republic of the Philippines, is an Archipelagic state, archipelagic country in Southeast Asia. Located in the western Pacific Ocean, it consists of List of islands of the Philippines, 7,641 islands, with a tot ...

* ''Tylonycteris pachypus pachypus'' - Indonesia

Biology and behaviour

Lesser bamboo bats typically roosts in the slit bored into the shoots of bamboo by

leaf beetle The beetle family Chrysomelidae, commonly known as leaf beetles, includes over 37,000 (and probably at least 50,000) species in more than 2,500 genera, making it one of the largest and most commonly encountered of all beetle families. Numerous s ...

larvae. The entrance slit to such cavities is too restrictive for most

predator Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common List of feeding behaviours, feeding behaviours that includes parasitism and micropredation ...

s, such as

snake Snakes are elongated limbless reptiles of the suborder Serpentes (). Cladistically squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales much like other members of the group. Many species of snakes have s ...

s, but the flattened head of the bamboo bat allows it to enter. Although the exact species vary across their range, in Malaysia, the preferred bamboo is '' Gigantochloa scortechinii'', and the beetles are most commonly '' Lasiochila goryi''. The bats sometimes use rock crevices or holes in trees as alternative roosting sites. Females tend to roost in small groups of about five individuals, although larger groupings of up to 38 have been reported. Males roost alone, or in small groups of up to six. Individuals switch roosts every day, and larger groupings tend to be temporary. The bats are insectivorous, with flies, beetles, and

hymenoptera Hymenoptera is a large order of insects, comprising the sawflies, wasps, bees, and ants. Over 150,000 living species of Hymenoptera have been described, in addition to over 2,000 extinct ones. Many of the species are parasitic. Females typi ...

ns forming the bulk of their diet. They catch insects on the wing, using echolocation calls that start at 125 kHz and drop to 50 kHz.

Reproduction

Lesser bamboo bats are

polygynous Polygyny () is a form of polygamy entailing the marriage of a man to several women. The term polygyny is from Neoclassical Greek πολυγυνία (); . Incidence Polygyny is more widespread in Africa than in any other continent. Some scholar ...

, with females mating with multiple males throughout the September to November breeding season. Unusually for a tropical species, the females store the sperm after mating, with ovulation and fertilisation not occurring until January. Gestation lasts 12 to 13 weeks, with the young being born between April and May. Most births are of non-identical twins, although identical twins, singletons, and triplets are born on occasion. Newborn young are blind and hairless and weigh about . The mother carries her young for the first couple of days, but then leaves them behind in the bamboo chamber. The young are weaned and able to fly 22 to 25 days after birth. When their fur first begins to grow it is dark in colour, taking on the lighter and more reddish adult hue by October of their first year. Both males and females are sexually mature by the start of the first breeding season after birth.

Parasites

Bat flies which have the lesser bamboo bat as its

host A host is a person responsible for guests at an event or for providing hospitality during it. Host may also refer to: Places * Host, Pennsylvania, a village in Berks County * Host Island, in the Wilhelm Archipelago, Antarctica People * ...

include ''

Basilia brevipes Basilia may refer to: * ''Basilia'' (fly), a genus of bat flies * Basilia (island) or Baltia, in Greco-Roman geography, a mythic island in northern Europe * Basilia (name), a feminine given name * Basel (Latin: Basilia), a city in Switzerland ...

'', '' Basilia majuscula'', and '' Basilia fletcheri''.

References

* * * {{Taxonbar, from=Q976615 Tylonycteris Bats of Asia Bats of Southeast Asia Bats of Borneo Bats of China Bats of India Bats of Indonesia Bats of Malaysia Bats of the Philippines Mammals of Bangladesh Mammals of Brunei Mammals of Cambodia Mammals of Hong Kong Mammals of Laos Mammals of Myanmar Mammals of Pakistan Mammals of Sri Lanka Mammals of Taiwan Mammals of Timor Mammals of Thailand Mammals of Vietnam Least concern biota of Asia Taxonomy articles created by Polbot Mammals described in 1840