View source for Lesser bamboo bat

{{Short description|Species of bat}}
{{speciesbox
| status = LC
| status_system = IUCN3.1
| status_ref = <ref name="iucn status 16 November 2021">{{cite iucn |author=Tu, V. |author2=Furey, N. |author3=Görföl, T. |author4=Csorba, G. |date=2020 |title=''Tylonycteris pachypus'' |volume=2020 |page=e.T22577A22086494 |doi=10.2305/IUCN.UK.2020-2.RLTS.T22577A22086494.en |access-date=16 November 2021}}</ref>
| image = Lesser Bamboo Bat.JPG
| genus = Tylonycteris
| species = pachypus
| authority = ([[Coenraad Jacob Temminck|Temminck]], 1840)
| synonyms = 
| range_map = Range_Tylonycteris_pachypus.png
}}

The '''lesser bamboo bat''' or '''lesser flat-headed bat''' ('''''Tylonycteris pachypus''''') is one of the smallest species of [[vesper bat]],<ref name=msw3>{{MSW3|id=13802290}}</ref> and is native to Southeast Asia.

==Description==
The bat, the size of a [[bumble bee]], is among the [[smallest organisms#Smallest mammal|smallest mammals]]{{Broken anchor|date=2025-06-20|bot=User:Cewbot/log/20201008/configuration|target_link=smallest organisms#Smallest mammal|reason= The anchor (Smallest mammal) [[Special:Diff/473137854|has been deleted]].|diff_id=473137854}} on earth,<ref>[http://www.si.edu/Encyclopedia_si/nmnh/batfacts.htm Smithsonian Institution]</ref> measuring about {{convert|4|cm|abbr=on}} in head-body length with a tail about {{convert|2.5|cm|abbr=on}} long and a wingspan of {{convert|19|cm|abbr=on}}. Adults weigh between {{convert|1.4|and|5.2|g|abbr=on}}.<ref name=Eguren2014>{{cite journal |author1=Eguren, R.E.  |author2=McBee, K. | date = October 2014 | title = ''Tylonycteris pachypus'' (Chiroptera: Vespertilionidae)| journal = Mammalian Species | volume = 46 | issue = 910 | pages = 33–39 | doi = 10.1644/910 |s2cid=84929706 | doi-access = free }}</ref>

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 (ear)|tragus]].<ref name=Eguren2014/> 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.<ref name=Medway1972>{{cite journal |author1=Medway, L.  |author2=Marshall A.G. | date = December 1972 | title = Roosting associations of flat-headed bats, ''Tylonycteris'' species (Chiroptera: Vespertilionidae) in Malaysia | journal = Journal of Zoology | volume = 168 | issue = 4 | pages = 463–482 | doi = 10.1111/j.1469-7998.1972.tb01362.x}}</ref> The wings have an [[aspect ratio (aeronautics)|aspect ratio]] of 6.2, allowing the bat to be agile in flight at the expense of a slow speed.<ref name=Zhang2007>{{cite journal | author = Zhang, L. | date = March 2007 | title = Morphology, echolocation and foraging behaviour in two sympatric sibling species of bat (''Tylonycteris pachypus'' and ''Tylonycteris robustula'') (Chiroptera: Vespertilionidae) | journal = Journal of Zoology | volume = 271 | issue = 3 | pages = 344–351 | doi = 10.1111/j.1469-7998.2006.00210.x|display-authors=etal}}</ref>

A 4.8 gram T. pachypus has about an 80&nbsp;mg brain.<ref name="Pitnick2006">{{cite journal |last1=Pitnick |first1=Scott |last2=Jones |first2=Kate E |last3=Wilkinson |first3=Gerald S |title=Mating system and brain size in bats |journal=Proceedings of the Royal Society B: Biological Sciences |date=22 March 2006 |volume=273 |issue=1587 |at=Appendix 1: 719–724 |doi=10.1098/rspb.2005.3367 |pmid=16608692|pmc=1560082 }}</ref>

==Distribution and habitat==
Lesser bamboo bats are found throughout [[Southeast Asia]] from [[Bangladesh]] to southern [[China]] and [[Indonesia]] and also in southern and eastern [[India]]. It inhabits deciduous forests with extensive areas of bamboo growth, at altitudes from sea level to {{convert|1260|m|abbr=on}}.<ref name="iucn status 16 November 2021" />

Five subspecies are recognised:<ref name=Eguren2014/>
* ''Tylonycteris pachypus aurex'' - India and Bangladesh
* ''Tylonycteris pachypus bhaktii'' - [[Lombok]]
* ''Tylonycteris pachypus fulvidus'' - China, [[Indochina]]
* ''Tylonycteris pachypus meyeri'' - [[Philippines]]
* ''Tylonycteris pachypus pachypus'' - Indonesia

==Biology and behaviour==

Lesser bamboo bats typically roosts in the slit bored into the shoots of bamboo by [[leaf beetle]] larvae. The entrance slit to such cavities is too restrictive for most [[predator]]s, such as [[snake]]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|Gigantochloa scortechinii]]'', and the beetles are most commonly ''[[Lasiochila goryi]]''. The bats sometimes use rock crevices or holes in trees as alternative roosting sites.<ref name=Medway1970>{{cite journal |author1=Medway, L.  |author2=Marshall, A.G. | date = August 1970 | title = Roost-site selection among flat-headed bats (''Tylonycteris'' spp.) | journal = Journal of Zoology | volume = 161 | issue = 2 | pages = 237–245 | doi = 10.1111/j.1469-7998.1970.tb02038.x}}</ref> 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.<ref name=Medway1970/><ref name=Hua2011>{{cite journal | author = Hua, P. | date = September 2011 | title = Hierarchical polygyny in multiparous lesser flat-headed bats | journal = Molecular Ecology | volume = 20 | issue = 17 | pages = 3669–3680 | doi = 10.1111/j.1365-294X.2011.05192.x|display-authors=etal | pmid=21824210| s2cid = 27648404 }}</ref> Individuals switch roosts every day, and larger groupings tend to be temporary.<ref name=Eguren2014/>

The bats are insectivorous, with flies, beetles, and [[hymenoptera]]ns forming the bulk of their diet.<ref name=Zhang2005>{{cite journal | author = Zhang, L. | author-link = :zh:张利标 |date=September 2005 |title=Diet of Flat-Headed Bats, Tylonycteris pachypus and T. robustula, in Guangxi, South China | journal = Journal of Mammalogy | volume = 86 | issue = 1 | pages = 61–66 | doi = 10.1644/1545-1542(2005)086<0061:DOFBTP>2.0.CO;2|display-authors=etal| doi-access = free }}
</ref> They catch insects on the wing, using echolocation calls that start at 125&nbsp;kHz and drop to 50&nbsp;kHz.<ref name=Eguren2014/>

===Reproduction===
Lesser bamboo bats are [[polygyny in animals|polygynous]], 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.<ref name=Hua2011/><ref name=Medway1972b>{{cite journal | author = Medway, L. | date = February 1972 | title = Reproductive cycles of the flat-headed bats ''Tylonycteris pachypus'' and ''T. robustula'' (Chiroptera: Vespertilioninae) in a humid equatorial environment | journal = Zoological Journal of the Linnean Society | volume = 51 | issue = 1 | pages = 33–61 | doi = 10.1111/j.1096-3642.1972.tb00772.x}}</ref>

Newborn young are blind and hairless and weigh about {{convert|0.6|g|abbr=on}}. 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.<ref name=Hua2011/><ref name=Medway1972b/>

==Parasites==

[[Bat flies]] which have the lesser bamboo bat as its [[host (biology)|host]] include ''[[Basilia brevipes]]'', ''[[Basilia majuscula]]'', and ''[[Basilia fletcheri]]''.<ref name="Theodor, 1956">{{cite journal|last1=Theodor|first1=Oskar|title=On the genus ''Tripselia'' and the group of ''Basilia bathybothyra'' (Nycteribiidae, Diptera)|journal=Parasitology|date=1956|volume=46|issue=3–4|pages=353–394|doi=10.1017/S003118200002655X|pmid=13378884|s2cid=40001351 }}</ref>

==References==
{{Reflist}}
{{Wikispecies|Tylonycteris pachypus}}
* {{NCBI taxid|258959}}
* {{ITIS|ID=632157}}
* {{Eol|326346}}

{{Vespertilionidae|V.|V.}}
{{Taxonbar|from=Q976615}}

[[Category:Tylonycteris]]
[[Category:Bats of Asia]]
[[Category:Bats of Southeast Asia]]
[[Category:Bats of Borneo]]
[[Category:Bats of China]]
[[Category:Bats of India]]
[[Category:Bats of Indonesia]]
[[Category:Bats of Malaysia]]
[[Category:Bats of the Philippines]]
[[Category:Mammals of Bangladesh]]
[[Category:Mammals of Brunei]]
[[Category:Mammals of Cambodia]]
[[Category:Mammals of Hong Kong]]
[[Category:Mammals of Laos]]
[[Category:Mammals of Myanmar]]
[[Category:Mammals of Pakistan]]
[[Category:Mammals of Sri Lanka]]
[[Category:Mammals of Taiwan]]
[[Category:Mammals of Timor]]
[[Category:Mammals of Thailand]]
[[Category:Mammals of Vietnam]]
[[Category:Least concern biota of Asia]]
[[Category:Taxonomy articles created by Polbot]]
[[Category:Mammals described in 1840]]