View source for Megabat

{{Short description|Family of fruit bats}}
{{Redirect|Fruit bat||Fruit bat (disambiguation)}}
{{Redirect|Fruit-eating bat|other species known as fruit-eating bats|Leaf-nosed bat}}
{{Use American English|date=February 2019}}
{{Use dmy dates|date=February 2019}}

{{Automatic taxobox
| fossil_range = {{fossil range|37.7|0|[[Late Eocene]] to present<ref name="Ducrocq1995"/>}}
| image = 047 Indian flying fox in Keoladeo National Park Photo by Giles Laurent.jpg
| image_caption = [[Indian flying fox]] (''Pteropus medius'')
| image_alt = Flying fox hanging from a tree
| taxon = Pteropodidae
| authority = [[John Edward Gray|Gray]], 1821
| display_parents = 2
| type_genus = ''[[Pteropus]]''
| type_genus_authority = [[Mathurin Jacques Brisson|Brisson]], 1762
| subdivision_ranks = Subfamilies
| subdivision = {{plainlist|
* [[Nyctimeninae]]
* [[Cynopterinae]]
* [[Harpyionycterinae]]
* [[Pteropodinae]]
* [[Rousettinae]]
* [[Eidolinae]]}}
| synonyms = Pteropidae (Gray, 1821)<ref name="mckenna 1997"/><br/>
Pteropodina <small>[[Charles Lucien Bonaparte|C. L. Bonaparte]], 1837</small><ref name="mckenna 1997">{{cite book|last1=McKenna| first1= M. C.| last2= Bell| first2= S. K.| year= 1997| title= Classification of mammals: above the species level| publisher= Columbia University Press|page=296| isbn=978-0-231-52853-5}}</ref>
| range_map = Worldwide distribution of Pteropodidae.jpg
| range_map_caption = Distribution of megabats
}}

'''Megabats''' constitute the [[Family (taxonomy)|family]] '''Pteropodidae''' of the [[Order (biology)|order]] [[Chiroptera]].  They are also called '''fruit bats''', '''Old World fruit bats''', or—especially the [[genus|genera]] ''[[Acerodon]]'' and ''[[Pteropus]]''—[[Pteropus|flying foxes]]. They are the only member of the [[Superfamily (taxonomy)|superfamily]] '''Pteropodoidea''', which is one of two superfamilies in the [[suborder]] [[Yinpterochiroptera]]. Internal divisions of Pteropodidae have varied since [[Subfamily|subfamilies]] were first proposed in 1917. From three subfamilies in the 1917 classification, six are now recognized, along with various [[Tribe (biology)|tribes]]. As of 2018, 197 [[species]] of megabat had been described.

The leading theory of the evolution of megabats has been determined primarily by genetic data, as the [[fossil]] record for this family is the most fragmented of all bats. They likely evolved in [[Australasia]], with the common ancestor of all living pteropodids existing approximately 31&nbsp;million years ago. Many of their lineages probably originated in [[Melanesia]], then dispersed over time to mainland Asia, the [[Mediterranean]], and [[Africa]]. Today, they are found in tropical and subtropical areas of Eurasia, Africa, and [[Oceania]].

The megabat family contains the largest bat species, with individuals of some species weighing up to {{cvt|1.45|kg|lb}} and having wingspans up to {{cvt|1.7|m|ft}}. Not all megabats are large-bodied; nearly a third of all species weigh less than {{cvt|50|g|oz}}. They can be differentiated from other bats due to their dog-like faces, clawed second digits, and reduced [[uropatagium]]. A small number of species have tails. Megabats maintain high metabolic rates and have several adaptations for flight, including rapid rates of oxygen consumption (VO<sub>2</sub>), the ability to sustain [[heart rate]]s of more than 700 beats per minute, and large lung volumes.

Most megabats are [[nocturnal]] or [[Crepuscular animal|crepuscular]], although a few species are active during the daytime. During the period of inactivity, they roost in trees or caves. Members of some species roost alone, while others form colonies of up to a million individuals. During the period of activity, they use [[flight]] to travel to food resources. With few exceptions, they are unable to [[animal echolocation|echolocate]], relying instead on keen senses of sight and smell to navigate and locate food. Most species are primarily [[frugivore|frugivorous]] and several are [[nectarivore|nectarivorous]]. Other less common food resources include leaves, pollen, twigs, and bark.

They reach sexual maturity slowly and have a low reproductive output. Most species have one offspring at a time after a pregnancy of four to six months. This low reproductive output means that after a population loss their numbers are slow to rebound. A quarter of all species are listed as [[threatened species|threatened]], mainly due to [[habitat destruction]] and [[overhunting]]. Megabats are a popular food source in some areas, leading to population declines and extinction. They are also of interest to those involved in [[public health]] as they are [[natural reservoir]]s of several viruses that can affect humans.

==Taxonomy and evolution==
===Taxonomic history===
{{See also|List of pteropodids}}
{{multiple image|perrow = 2|total_width=300
| image1 = Short-nosed Fruit Bat (Cynopterus sphinx) Photograph By Shantanu Kuveskar.jpg
| image2 = Indian Flying Fox (Pteropus giganteus) Kolkata West Bengal India 27042013.png
| image3 = Nyctimene robinsoni.jpg
| image4 = Skraidantis egipto šuo (cropped).jpg
| footer = Megabats of various subfamilies. Clockwise from upper left: [[greater short-nosed fruit bat]] (Cynopterinae), [[Indian flying fox]] (Pteropodinae), [[Egyptian fruit bat]] (Rousettinae), [[eastern tube-nosed bat]] (Nyctimeninae).
}}
{{cladogram|align=right|style=width:30%;line-height:85%|caption=Internal relationships of African Pteropodidae based on combined evidence of [[mitochondrial DNA|mitochondrial]] and [[nuclear DNA|nuclear]] DNA. One species each of Pteropodinae, Nyctimeninae, and Cynopterinae, which are not found in Africa, were included as [[Outgroup (cladistics)|outgroups]].<ref name="Almeida 2016"/>
|cladogram={{clade
|label1=Pteropodidae
|1={{clade
|1={{clade
|1=[[Pteropodinae]]
|2={{clade
  |1=[[Nyctimeninae]]
  |2={{clade
    |1=[[Cynopterinae]]
    |2=[[Eidolinae]] }} }} }}
|label2=[[Rousettinae]]
|2={{clade
    |1=[[Scotonycterini]]
    |2={{clade
      |1=[[Eonycterini]]
      |2={{clade
       |1=[[Rousettini]]
       |2={{clade
         |1=[[Stenonycterini]]
         |2={{clade
           |1={{clade
             |1=[[Plerotini]]
             |2=[[Myonycterini]] }}
           |2=Epomophorini
}} }} }} }} }} }} }} }}
The family Pteropodidae was first described in 1821 by British zoologist [[John Edward Gray]]. He named the family "Pteropidae" (after the genus ''[[Pteropus]]'') and placed it within the now-defunct order Fructivorae.<ref name="Gray">{{cite journal|last=Gray|first=J. E.|year=1821|title=On the natural arrangement of vertebrose animals|url=http://www.rhinoresourcecenter.com/index.php?s=1&act=pdfviewer&id=1175857325&folder=117|journal=London Medical Repository|issue=25|page=299}}</ref> Fructivorae contained one other family, the now-defunct Cephalotidae, containing one genus, ''Cephalotes''<ref name="Gray"/> (now recognized as a synonym of ''[[Dobsonia]]'').<ref name="Miller, 1907">{{cite journal|last1=Miller|first1=Gerrit S. Jr.|title=The Families and Genera of Bats|journal=United States National Museum Bulletin|date=1907|volume=57|issue=490 |page=63|doi=10.1086/278854 |bibcode=1907ANat...41..671. |url=https://biodiversitylibrary.org/page/51112208}}</ref> Gray's spelling was possibly based on a misunderstanding of the suffix of "''Pteropus''".<ref name="Hutcheon 2006">{{cite journal|last1=Hutcheon| first1= J. M.| last2= Kirsch| first2=J. A.| year=2006| title= A moveable face: deconstructing the Microchiroptera and a new classification of extant bats| journal= Acta Chiropterologica| volume= 8| issue=1| pages= 1–10| doi= 10.3161/1733-5329(2006)8[1:AMFDTM]2.0.CO;2| s2cid= 85948117}}</ref> "''Pteropus''" comes from [[Ancient Greek]] {{Transliteration|grc|pterón}} meaning "wing" and {{Transliteration|grc|poús}} meaning "foot".<ref>{{cite web|url=https://www.merriam-webster.com/dictionary/Pteropus| website=Merriam-Webster|access-date=22 May 2019| title=Definition of PTEROPUS}}</ref> The Greek word ''pous'' of ''Pteropus'' is from the stem word ''pod-''; therefore, Latinizing ''Pteropus'' correctly results in the prefix "''Pteropod-''".<ref name="Jackson">{{cite book| last1=Jackson| first1= S.| last2= Jackson| first2=S. M.| last3= Groves| first3= C.| year=2015| title= Taxonomy of Australian Mammals| publisher= [[Csiro Publishing]]|isbn=978-1-4863-0013-6}}</ref>{{rp|230}} French biologist [[Charles Lucien Bonaparte]] was the first to use the corrected spelling Pteropodidae in 1838.<ref name="Jackson"/>{{Rp|230}}

In 1875, the zoologist [[George Edward Dobson]] was the first to split the order Chiroptera (bats) into two [[suborder]]s: '''Megachiroptera''' (sometimes listed as '''Macrochiroptera''') and [[Microchiroptera]], which are commonly abbreviated to megabats and microbats.<ref name="Dobson 1875">{{cite journal|last=Dobson|first=G. E.| year=1875| title=Conspectus of the suborders, families, and genera of Chiroptera arranged according to their natural affinities| journal=[[Journal of Natural History|The Annals and Magazine of Natural History; Zoology, Botany, and Geology]]|series=4|volume=16|url=https://biodiversitylibrary.org/page/25128227| issue=95}}</ref> Dobson selected these names to allude to the body size differences of the two groups, with many fruit-eating bats being larger than insect-eating bats. Pteropodidae was the only family he included within Megachiroptera.<ref name="Hutcheon 2006"/><ref name="Dobson 1875"/>

A 2001 study found that the dichotomy of megabats and microbats did not accurately reflect their evolutionary relationships. Instead of Megachiroptera and Microchiroptera, the study's authors proposed the new suborders [[Yinpterochiroptera]] and [[Yangochiroptera]].<ref name="Springer"/> This classification scheme has been verified several times subsequently and remains widely supported as of 2019.<ref>{{cite journal|last1=Lei| first1= M.| last2= Dong| first2= D.|year=2016| title= Phylogenomic analyses of bat subordinal relationships based on transcriptome data| journal= [[Scientific Reports]]| volume= 6| article-number= 27726| bibcode= 2016NatSR...627726L| doi= 10.1038/srep27726| pmid= 27291671| pmc= 4904216}}</ref><ref>{{cite journal|doi=10.1016/j.cub.2013.09.014|pmid=24184098|title=Phylogenomic Analyses Elucidate the Evolutionary Relationships of Bats|journal=[[Current Biology]]|volume=23|issue=22|pages=2262–2267|year=2013|last1=Tsagkogeorga|first1=G.|last2=Parker|first2=J.|last3=Stupka|first3=E.|last4=Cotton|first4=J.&nbsp;A.|last5=Rossiter|first5=S.&nbsp;J.|s2cid=9133016|doi-access=free|bibcode=2013CBio...23.2262T }}</ref><ref>{{cite journal|doi=10.3109/19401736.2013.809451|pmid=23815317|title=Characterization of the mitochondrial genome of ''Rousettus'' leschenaulti|journal=[[Mitochondrial DNA (journal)|Mitochondrial DNA]]|volume=25|issue=6|pages=443–444|year=2014|last1=Szcześniak|first1=M.|last2=Yoneda|first2=M.|last3=Sato|first3=H.|last4=Makałowska|first4=I.| last5=Kyuwa|first5=S.|last6=Sugano|first6=S.|last7=Suzuki|first7=Y.|last8=Makałowski|first8=W.|last9=Kai|first9=C.|s2cid=207657381}}</ref><ref>{{cite journal|doi=10.1126/science.1105113 |pmid=15681385 |title=A Molecular Phylogeny for Bats Illuminates Biogeography and the Fossil Record |journal=[[Science (journal)|Science]] |volume=307 |issue=5709 |pages=580–584 |year=2005 |last1=Teeling |first1=E. C. |last2=Springer |first2=M. S. |last3=Madsen |first3=O. |last4=Bates |first4=P. |last5=O'Brien |first5=S. J. |last6=Murphy |first6=W. J. |bibcode=2005Sci...307..580T |s2cid=25912333 }}</ref> Since 2005, this suborder has alternatively been called "Pteropodiformes".<ref name="Jackson"/>{{rp|520–521}} Yinpterochiroptera contained species formerly included in Megachiroptera (all of Pteropodidae), as well as several families formerly included in Microchiroptera: [[Megadermatidae]], [[Rhinolophidae]], [[Nycteridae]], [[Craseonycteridae]], and [[Rhinopomatidae]].<ref name="Springer">{{cite journal|doi=10.1073/pnas.111551998|pmid=11353869|pmc=33452|title=Integrated fossil and molecular data reconstruct bat echolocation|journal=Proceedings of the National Academy of Sciences|volume=98|issue=11|pages=6241–6246|year=2001|last1=Springer|first1=M. S.|last2=Teeling|first2=E. C.|last3=Madsen|first3=O.|last4=Stanhope|first4=M. J.|last5=De Jong|first5=W. W.|bibcode=2001PNAS...98.6241S|doi-access=free}}</ref> Two [[superfamily (taxonomy)|superfamilies]] comprise Yinpterochiroptera: Rhinolophoidea—containing the above families formerly in Microchiroptera—and Pteropodoidea, which only contains Pteropodidae.<ref>{{cite book|last=Ungar|first=P.| title=Mammal Teeth: Origin, Evolution, and Diversity| year=2010|publisher=[[JHU Press]]|isbn=978-0-8018-9951-5|page=166}}</ref>

In 1917, Danish [[mammalogist]] [[Knud Andersen (mammalogist)|Knud Andersen]] divided Pteropodidae into three subfamilies: Macroglossinae, Pteropinae (corrected to [[Pteropodinae]]), and Harpyionycterinae.<ref>{{cite journal|doi=10.1111/j.1096-0031.2003.tb00385.x|title=A phylogeny of megachiropteran bats (Mammalia: Chiroptera: Pteropodidae) based on direct optimization analysis of one nuclear and four mitochondrial genes|journal=[[Cladistics (journal)|Cladistics]]|volume=19|issue=6|pages=496–511|year=2003|last1=Giannini|first1=N. P.|last2=Simmons|first2=N. B.|pmid=34905855|s2cid=84696546}}</ref>{{Rp|496}} A 1995 study found that Macroglossinae as previously defined, containing the genera ''[[Eonycteris]]'', ''[[Notopteris]]'', ''[[Macroglossus]]'', ''[[Syconycteris]]'', ''[[Melonycteris]]'', and ''[[Megaloglossus]]'', was [[paraphyly|paraphyletic]], meaning that the subfamily did not group all the descendants of a common ancestor.<ref>{{cite journal|doi=10.1093/sysbio/44.2.209|title=A Phylogeny of Indo-West Pacific Megachiroptera Based on Ribosomal DNA|journal=[[Systematic Biology]]|volume=44|issue=2|pages=209–220|year=1995|last1=Colgan|first1=D. J.|last2=Flannery|first2=T. F.}}</ref>{{Rp|214}} Subsequent publications consider Macroglossini as a tribe within Pteropodinae that contains only ''Macroglossus'' and ''Syconycteris''.<ref>{{cite journal|last1=Bergmans|first1=W.|year=1997|title=Taxonomy and biogeography of African fruit bats (Mammalia, Megachiroptera). 5. The genera Lissonycteris Andersen, 1912, Myonycteris Matschie, 1899 and Megaloglossus Pagenstecher, 1885; general remarks and conclusions; annex: key to all species|journal=Beaufortia|volume=47|issue=2|page=69}}</ref><ref name="Almeida 2011"/> ''Eonycteris'' and ''Melonycteris'' are within other tribes in Pteropodinae,<ref name="Almeida 2016"/><ref name="Almeida 2011"/> ''Megaloglossus'' was placed in the tribe Myonycterini of the subfamily Rousettinae, and ''Notopteris'' is of uncertain placement.<ref name="Almeida 2011"/>

Other subfamilies and tribes within Pteropodidae have also undergone changes since Andersen's 1917 publication.<ref name="Almeida 2011"/> In 1997, the pteropodids were classified into six subfamilies and nine tribes based on their [[morphology (biology)|morphology]], or physical characteristics.<ref name="Almeida 2011"/> A 2011 genetic study concluded that some of these subfamilies were paraphyletic and therefore they did not accurately depict the relationships among megabat species. Three of the subfamilies proposed in 1997 based on morphology received support: Cynopterinae, Harpyionycterinae, and Nyctimeninae. The other three [[clade]]s recovered in this study consisted of Macroglossini, Epomophorinae + Rousettini, and Pteropodini + ''Melonycteris''.<ref name="Almeida 2011"/> A 2016 genetic study focused only on African pteropodids (Harpyionycterinae, Rousettinae, and Epomophorinae) also challenged the 1997 classification. All species formerly included in Epomophorinae were moved to Rousettinae, which was subdivided into additional tribes. The genus ''[[Eidolon (bat)|Eidolon]]'', formerly in the tribe Rousettini of Rousettinae, was moved to its own subfamily, [[Eidolinae]].<ref name="Almeida 2016">{{cite journal|doi=10.3161/15081109ACC2016.18.1.003|title=The Evolutionary History of the African Fruit Bats (Chiroptera: Pteropodidae)|journal=Acta Chiropterologica|volume=18|pages=73–90|year=2016|last1=Almeida|first1=F.|last2=Giannini|first2=N. P.|last3=Simmons|first3=N. B.|s2cid=89415407|url=https://www.researchgate.net/publication/303742900|hdl=11336/12847|hdl-access=free}}</ref>

In 1984, an additional pteropodid subfamily, Propottininae, was proposed, representing one extinct species described from a fossil discovered in Africa, ''[[Propotto leakeyi]]''.<ref>{{cite journal|last= Butler| first= P. M.| year= 1984| title= Macroscelidea, Insectivora and Chiroptera from the Miocene of east Africa| journal=Palaeovertebrata| volume= 14| issue=3| page= 175|url=https://palaeovertebrata.com/Articles/sendFile/116/published_article}}</ref> In 2018 the fossils were reexamined and determined to represent a [[lemur]].<ref>{{cite journal|doi=10.1038/s41467-018-05648-w|pmid=30131571|pmc=6104046|title=Fossil lemurs from Egypt and Kenya suggest an African origin for Madagascar's aye-aye|journal=[[Nature Communications]]|volume=9|issue=1|page=3193|year=2018|last1=Gunnell|first1=G. F.|last2=Boyer|first2=D. M.|last3=Friscia|first3=A. R.|last4=Heritage|first4=S.|last5=Manthi|first5=F. K.|last6=Miller|first6=E. R.|last7=Sallam|first7=H. M.|last8=Simmons|first8=N. B.|last9=Stevens|first9=N. J.|last10=Seiffert|first10=E. R.|bibcode=2018NatCo...9.3193G}}</ref> As of 2018, there were 197 described species of megabat,<ref>{{Cite journal|last1=Burgin|first1=Connor J|last2=Colella|first2=Jocelyn P|last3=Kahn|first3=Philip L|last4=Upham|first4=Nathan S|date=2018|title=How many species of mammals are there?|journal=Journal of Mammalogy|volume=99|issue=1|pages=1–14|doi=10.1093/jmammal/gyx147|s2cid=90797674|issn=0022-2372|doi-access=free}}</ref> around a third of which are flying foxes of the genus ''Pteropus''.<ref>{{cite web|url=https://www.iucnredlist.org/search/stats| title=<nowiki>Taxonomy=Pteropus</nowiki>| website=IUCN Red List of Threatened Species|year=2019| access-date=19 May 2019}}</ref>

===Evolutionary history===
====Fossil record and divergence times====
[[File:Archaeopteropus transiens.JPG|left|thumb|285x285px|The large [[Oligocene]] bat ''[[Archaeopteropus]]'' evolved a very similar morphology to pteropodids, but its taxonomic affinities remain controversial]]
The fossil record for pteropodid bats is the most incomplete of any bat family. Although the poor skeletal record of Chiroptera is probably from how fragile bat skeletons are, Pteropodidae still have the most incomplete despite generally having the biggest and most sturdy skeletons. It is also surprising that Pteropodidae are the least represented because they were the first major group to diverge.<ref>{{Cite journal |last1=Brown |first1=Emily E. |last2=Cashmore |first2=Daniel D. |last3=Simmons |first3=Nancy B. |last4=Butler |first4=Richard J. |date=2019-03-25 |editor-last=Mannion |editor-first=Philip |title=Quantifying the completeness of the bat fossil record |url=https://onlinelibrary.wiley.com/doi/epdf/10.1111/pala.12426 |journal=Palaeontology |language=en |publisher=Paleobiology Database |volume=62 |issue=5 |pages=757–776 |doi=10.1111/pala.12426 |bibcode=2019Palgy..62..757B |s2cid=133901426 |issn=0031-0239|url-access=subscription }}</ref> Several factors could explain why so few pteropodid fossils have been discovered: tropical regions where their fossils might be found are under-sampled relative to Europe and North America; conditions for fossilization are poor in the tropics, which could lead to fewer fossils overall; and even when fossils are formed, they may be destroyed by subsequent geological activity.<ref>{{cite journal|last1=Eiting|first1=T. P.|last2=Gunnell|first2=G. F.|year=2009|title=Global Completeness of the Bat Fossil Record|journal=Journal of Mammalian Evolution|volume=16|issue=3|page=157|doi=10.1007/s10914-009-9118-x|s2cid=5923450}}</ref> It is estimated that more than 98% of pteropodid fossil history is missing.<ref name="Teeling 2005">{{cite journal|doi=10.1126/science.1105113|pmid=15681385|title=A Molecular Phylogeny for Bats Illuminates Biogeography and the Fossil Record|journal=Science|volume=307|issue=5709|pages=580–584|year=2005|last1=Teeling|first1=E. C.|last2=Springer|first2=M. S.|last3=Madsen|first3=O.|last4=Bates|first4=P.|last5=O'Brien|first5=S. J.|last6=Murphy|first6=W. J.|bibcode=2005Sci...307..580T|s2cid=25912333| url=https://courses.cit.cornell.edu/bionb4240/Reprints/Bat%20phylogeny%20Teeling%20et%20al%202005.pdf}}</ref> Even without fossils, the age and divergence times of the family can still be estimated by using [[computational phylogenetics]]. Pteropodidae split from the superfamily [[Rhinolophoidea]] (which contains all the other families of the suborder Yinpterochiroptera) approximately 58&nbsp;Mya (million years ago).<ref name="Teeling 2005"/> The ancestor of the [[crown group]] of Pteropodidae, or all living species, lived approximately 31&nbsp;Mya.<ref name="Almeida 2009"/>

''[[Archaeopteropus]]'', a giant earliest [[Oligocene]]-aged bat from Italy known from a near-complete skeleton, was often previously cited as the earliest known megabat relative in the fossil record. It displays many close morphological similarities with modern megabats, including a very large size (a total estimated wingspan of {{Convert|82 to 90|cm|ft}}), a broad membrane connecting the finger and legs, and limb morphology suggesting an arboreal lifestyle reminiscent of modern fruit bats.<ref name=":0">{{Cite journal |last1=Pandolfi|first1=Luca|last2=Carnevale|first2=Giorgio|last3=Costeur|first3=Loic|last4=Favero|first4=Letizia Del|last5=Fornasiero|first5=Mariagabriella|last6=Ghezzo|first6=Elena|last7=Maiorino|first7=Leonardo|last8=Mietto|first8=Paolo|last9=Piras|first9=Paolo|last10=Rook|first10=Lorenzo|last11=Sansalone|first11=Gabriele|last12=Kotsakis|first12=Tassos|date=2017-02-01|title=Reassessing the earliest Oligocene vertebrate assemblage of Monteviale (Vicenza, Italy)|url=https://www.tandfonline.com/doi/full/10.1080/14772019.2016.1147170|journal=Journal of Systematic Palaeontology|language=en|volume=15|issue=2|pages=83–127|bibcode=2017JSPal..15...83P|doi=10.1080/14772019.2016.1147170|issn=1477-2019|url-access=subscription}}</ref><ref>{{Cite journal |last=Adams|first=R. A.|last2=Carter|first2=R. T.|last3=Hardgrave|first3=A. J.|date=2025|title=Monkeying around with bat scapulae: Old World fruit bats show arboreal adaptations of primates lacking in New World fruit bats|url=https://zslpublications.onlinelibrary.wiley.com/doi/10.1111/jzo.70000|journal=Journal of Zoology|language=en|volume=326|issue=1|pages=54–64|doi=10.1111/jzo.70000|issn=0952-8369}}</ref> However, the presence of a bony [[calcar]], which is not present in pteropodids, suggests that it may not belong to this group.<ref>{{Cite journal |last=Schutt|first=William A.|last2=Simmons|first2=Nancy B.|date=1998-03-01|title=Morphology and Homology of the Chiropteran Calcar, with Comments on the Phylogenetic Relationships of Archaeopteropus|url=https://doi.org/10.1023/A:1020566902992|journal=Journal of Mammalian Evolution|language=en|volume=5|issue=1|pages=1–32|doi=10.1023/A:1020566902992|issn=1573-7055}}</ref> Although the head and teeth are too poorly-preserved to deduce its diet, it also may potentially display adaptations for an insectivorous rather than a frugivorous lifestyle.<ref>{{Cite web |title=Details - The case for chiropteran monophyly. American Museum novitates ; no. 3103 - Biodiversity Heritage Library|url=https://www.biodiversitylibrary.org/bibliography/93230|archive-url=http://web.archive.org/web/20250322212201/https://www.biodiversitylibrary.org/bibliography/93230|archive-date=2025-03-22|access-date=2026-05-01|website=www.biodiversitylibrary.org|language=en}}</ref> The taxonomic affiliation of ''Archaeopteropus'' still remains contentious.<ref>{{Cite journal |last=Jones|first=Matthew F.|last2=Beard|first2=K. Christopher|last3=Simmons|first3=Nancy B.|date=2024-05-02|title=Phylogeny and systematics of early Paleogene bats|url=https://doi.org/10.1007/s10914-024-09705-8|journal=Journal of Mammalian Evolution|language=en|volume=31|issue=2|pages=18|doi=10.1007/s10914-024-09705-8|issn=1573-7055}}</ref>

Excluding ''Archaeopteropus'', the oldest known fossil record of pteropodids are isolated teeth recovered from the [[Priabonian|Late Eocene]]-aged Wai Lek pit of the [[Krabi Basin]] in Thailand.<ref name="Ducrocq1995">{{Cite journal |last=Ducrocq |first=Stéphane |last2=Chaimanee |first2=Yaowalak |last3=Suteethorn |first3=Varavudh |last4=Jaeger |first4=Jean-Jacques |date=1995-07-01 |title=Mammalian faunas and the ages of the continental Tertiary fossiliferous localities from Thailand |url=https://www.sciencedirect.com/science/article/pii/0743954795000216 |journal=Journal of Southeast Asian Earth Sciences |volume=12 |issue=1 |pages=65–78 |doi=10.1016/0743-9547(95)00021-6 |issn=0743-9547}}</ref>

====Biogeography====
[[File:Oceania UN Geoscheme - Map of Melanesia cropped.jpg|thumb|upright=1.2|alt=A map of Oceania with the islands of Melanesia highlighted in pink.|Melanesia, where many megabat subfamilies are likely to have originated]]
The family Pteropodidae likely originated in [[Australasia]] based on [[biogeography|biogeographic reconstructions]].<ref name="Almeida 2016"/> Other biogeographic analyses have suggested that the [[Melanesia]]n Islands, including [[New Guinea]], are a plausible candidate for the origin of most megabat subfamilies, with the exception of Cynopterinae;<ref name="Almeida 2011">{{cite journal|doi=10.1186/1471-2148-11-281|pmid=21961908|pmc=3199269|title=Evolutionary relationships of the old world fruit bats (Chiroptera, Pteropodidae): Another star phylogeny?|journal=[[BMC Evolutionary Biology]]|volume=11|page=281|year=2011|last1=Almeida|first1=F. C.| last2=Giannini|first2=N. P.|last3=Desalle|first3=R.|last4=Simmons|first4=N. B. |issue=1 |doi-access=free |bibcode=2011BMCEE..11..281A }}</ref> the cynopterines likely originated on the [[Sunda Shelf]] based on results of a Weighted Ancestral Area Analysis of six nuclear and mitochondrial genes.<ref name="Almeida 2009">{{cite journal|doi=10.1016/j.ympev.2009.07.035|pmid=19660560|title=The phylogenetic relationships of cynopterine fruit bats (Chiroptera: Pteropodidae: Cynopterinae)|journal=[[Molecular Phylogenetics and Evolution]]|volume=53|issue=3|pages=772–783|year=2009|last1=Almeida|first1=F. C.|last2=Giannini|first2=N. P.|last3=Desalle|first3=Rob|last4=Simmons|first4=N. B.|hdl=11336/74530|hdl-access=free}}</ref> From these regions, pteropodids colonized other areas, including continental Asia and Africa. Megabats reached Africa in at least four distinct events. The four proposed events are represented by (1) ''[[Scotonycteris]]'', (2) ''[[Rousettus]]'', (3) Scotonycterini, and (4) the "endemic Africa clade", which includes Stenonycterini, Plerotini, Myonycterini, and Epomophorini, according to a 2016 study. It is unknown when megabats reached Africa, but several tribes (Scotonycterini, Stenonycterini, Plerotini, Myonycterini, and Epomophorini) were present by the [[Late Miocene]]. How megabats reached Africa is also unknown. It has been proposed that they could have arrived via the [[Middle East]] before it became more arid at the end of the Miocene. Conversely, they could have reached the continent via the [[Gomphotherium land bridge]], which connected Africa and the [[Arabian Peninsula]] to [[Eurasia]]. The genus ''Pteropus'' (flying foxes), which is not found on mainland Africa, is proposed to have dispersed from Melanesia via [[island hopping]] across the [[Indian Ocean]];<ref>{{cite journal|doi=10.1016/j.ympev.2009.02.010|pmid=19249376|title=Multiple colonisations of the western Indian Ocean by Pteropus fruit bats (Megachiroptera: Pteropodidae): The furthest islands were colonised first|journal=Molecular Phylogenetics and Evolution|volume=51|issue=2|pages=294–303|year=2009|last1=O'Brien|first1=J.|last2=Mariani|first2=C.|last3=Olson|first3=L.|last4=Russell|first4=A. L.|last5=Say|first5=L.|last6=Yoder|first6=A. D.|last7=Hayden|first7=T. J.|bibcode=2009MolPE..51..294O }}</ref> this is less likely for other megabat genera, which have smaller body sizes and thus have more limited flight capabilities.<ref name="Almeida 2016"/>

====Echolocation====
Megabats are the only family of bats incapable of [[larynx|laryngeal]] echolocation. It is unclear whether the common ancestor of all bats was capable of echolocation, and thus echolocation was lost in the megabat lineage, or multiple bat lineages independently evolved the ability to echolocate (the superfamily [[Rhinolophoidea]] and the suborder [[Yangochiroptera]]). This unknown element of bat evolution has been called a "grand challenge in biology".<ref>{{cite book | vauthors = Teeling EC, Jones G, Rossiter SJ |chapter=Phylogeny, Genes, and Hearing: Implications for the Evolution of Echolocation in Bats |date=2016 |pages=25–54 | veditors = Fenton MB, Grinnell AD, Popper AN, Fay RN |series=Springer Handbook of Auditory Research |publisher=Springer | location = New York |doi=10.1007/978-1-4939-3527-7_2 |isbn=978-1-4939-3527-7 |title=Bat Bioacoustics |volume=54 }}</ref> A 2017 study of bat [[ontogeny]] (embryonic development) found evidence that megabat embryos at first have large, developed [[cochlea]] similar to echolocating microbats, though at birth they have small cochlea similar to non-echolocating mammals. This evidence supports that laryngeal echolocation evolved once among bats, and was lost in pteropodids, rather than evolving twice independently.<ref>{{cite journal|doi=10.1038/s41559-016-0021|pmid=28812602|title=Prenatal development supports a single origin of laryngeal echolocation in bats|journal=Nature Ecology & Evolution|volume=1|issue=2|page=21|year=2017|last1=Wang|first1=Zhe|last2=Zhu|first2=Tengteng|last3=Xue|first3=Huiling|last4=Fang|first4=Na|last5=Zhang|first5=Junpeng|last6=Zhang|first6=Libiao|last7=Pang|first7=Jian|last8=Teeling|first8=Emma C.|last9=Zhang|first9=Shuyi|s2cid=29068452}}</ref> Megabats in the genus ''Rousettus'' are capable of primitive echolocation through clicking their tongues.<ref>{{cite journal | last1= Holland| first1= R. A.| last2= Waters| first2= D. A.| last3= Rayner| first3= J. M.| title = Echolocation signal structure in the Megachiropteran bat Rousettus aegyptiacus Geoffroy 1810 | journal = [[The Journal of Experimental Biology]] | volume = 207 | issue = Pt 25 | pages = 4361–4369 | date = December 2004 | pmid = 15557022 | doi = 10.1242/jeb.01288 | bibcode= 2004JExpB.207.4361H| s2cid= 2715542}}</ref> Some species&mdash;the [[cave nectar bat]] (''Eonycteris spelaea''), [[lesser short-nosed fruit bat]] (''Cynopterus brachyotis''), and the [[long-tongued fruit bat]] (''Macroglossus sobrinus'')&mdash;have been shown to create clicks similar to those of echolocating bats using their wings.<ref name=Boonman2014>{{cite journal | last1 = Boonman| first1= A.| last2= Bumrungsri| first2= S.| last3= Yovel| first3= Y. | title = Nonecholocating fruit bats produce biosonar clicks with their wings | journal = Current Biology | volume = 24 | issue = 24 | pages = 2962–2967 | date = December 2014 | pmid = 25484290 | doi = 10.1016/j.cub.2014.10.077 | s2cid= 17789233| doi-access = free | bibcode= 2014CBio...24.2962B}}</ref>

Both echolocation and [[Bat flight|flight]] are energetically expensive processes separately, although no increase in flight energy expenditure was found for two species of echolocating bats compared with other bats and birds .<ref>{{cite journal | last1= Speakman| first1= J. R.| last2= Racey| first2= P. A. | title = No cost of echolocation for bats in flight | journal = Nature | volume = 350 | issue = 6317 | pages = 421–423 | date = April 1991 | pmid = 2011191 | doi = 10.1038/350421a0 | bibcode = 1991Natur.350..421S | s2cid= 4314715}}</ref> Echolocating bats couple sound production with the mechanisms engaged for flight, allowing them to reduce the additional energy burden of echolocation. Instead of pressurizing a bolus of air for the production of sound, laryngeally echolocating bats likely use the force of the downbeat of their wings to pressurize the air, cutting energetic costs by synchronizing wingbeats and echolocation.<ref>{{cite journal | last1=  Lancaster| first1= W. C.| last2= Henson| first2= O. W.| last3= Keating| first3= A. W. | title = Respiratory muscle activity in relation to vocalization in flying bats | journal = The Journal of Experimental Biology | volume = 198 | issue = Pt 1 | pages = 175–191 | date = January 1995 | doi= 10.1242/jeb.198.1.175| pmid = 7891034| bibcode= 1995JExpB.198..175L|url=http://jeb.biologists.org/content/jexbio/198/1/175.full.pdf }}</ref> The loss of echolocation (or conversely, the lack of its evolution) may be due to the uncoupling of flight and echolocation in megabats.<ref name="Book" /> The larger average body size of megabats compared to echolocating bats<ref name="Hutcheon 2004" /> suggests a larger body size disrupts the flight-echolocation coupling and made echolocation too energetically expensive to be conserved in megabats.<ref name="Book">{{cite book |last=Altringham |first=J. D. | name-list-style = vanc |year=2011 |chapter=Echolocation and other senses| title=Bats: From Evolution to Conservation|location=New York |publisher=[[Oxford University Press]] |isbn=978-0-19-920711-4 }}</ref>

==Description==
===Appearance===
[[File:Mariana Fruit Bat.jpg|thumb|upright|alt=A bat with black fur viewed in profile from the back. It has a bright yellow mantle of fur on the back of its neck.|Contrasting yellow mantle of the [[Mariana fruit bat]] (''Pteropus mariannus'')]]
Megabats take their name from their larger weight and size; the largest, the [[great flying fox]] (''Pteropus neohibernicus''), weighs up to {{cvt|1.6|kg|lb}};<ref>{{cite book| last=Flannery| first= T.| year=1995| title=Mammals of the South-West Pacific & Moluccan Islands| page= 271| isbn=0-8014-3150-6| publisher=Cornell University Press}}</ref> some members of ''Acerodon'' and ''Pteropus'' have wingspans reaching up to {{cvt|1.7|m|ft}}.<ref name="Nowak 1994"/>{{rp|p=48}} Despite the fact that body size was a defining characteristic that Dobson used to separate microbats and megabats, not all species of megabat are larger than microbats; the [[spotted-winged fruit bat]] (''Balionycteris maculata''), a megabat, weighs only {{cvt|14.2|g|oz}}.<ref name="Hutcheon 2004">{{cite journal|doi=10.1023/B:JOMM.0000047340.25620.89|title=Are Megabats Big?|journal=[[Journal of Mammalian Evolution]]|volume=11|issue=3/4|pages=257–277|year=2004|last1=Hutcheon|first1=J. M.|last2=Garland|first2=T. Jr.|s2cid=11528722}}</ref> The flying foxes of ''Pteropus'' and ''[[Acerodon]]'' are often taken as exemplars of the whole family in terms of body size. In reality, these genera are outliers, creating a misconception of the true size of most megabat species.<ref name="Hutcheon 2006"/> A 2004 review stated that 28% of megabat species weigh less than {{cvt|50|g|oz}}.<ref name="Hutcheon 2004"/>

Megabats can be distinguished from microbats in appearance by their dog-like faces, by the presence of claws on the second digit {{xref|(see: {{slink||Postcrania}}, below)}}, and by their simple ears.<ref>{{cite book|last1=Geist| first1= V.| first2= D. G.| last2= Kleiman| first3= M. C.| last3= McDade| title= Grzimek's Animal Life Encyclopedia Mammals II| volume= 13| edition= 2nd| publisher=[[Gale (publisher)|Gale]]| year= 2004|page=309}}</ref> The simple appearance of the ear is due in part to the lack of [[tragus (ear)|tragi]] (cartilage flaps projecting in front of the ear canal), which are found in many microbat species. Megabats of the genus ''[[Nyctimene (genus)|Nyctimene]]'' appear less dog-like, with shorter faces and tubular nostrils.<ref name="Nelson"/> A 2011 study of 167 megabat species found that while the majority (63%) have fur that is a uniform color, other patterns are seen in this family. These include [[countershading]] in four percent of species, a neck band or mantle in five percent of species, stripes in ten percent of species, and spots in nineteen percent of species.<ref>{{cite journal|doi=10.1371/journal.pone.0025845|pmid=21991371|pmc=3185059|title=Roosting Ecology and the Evolution of Pelage Markings in Bats|journal=[[PLOS One]]|volume=6|issue=10|article-number=e25845|year=2011|last1=Santana|first1=S. E.|last2=Dial|first2=T. O.|last3=Eiting|first3=T. P.|last4=Alfaro|first4=M. E.|bibcode=2011PLoSO...625845S|doi-access=free}}</ref>

Unlike microbats, megabats have a greatly reduced [[interfemoral membrane|uropatagium]], which is an expanse of flight membrane that runs between the hind limbs.<ref name="Hall"/> Additionally, the tail is absent or greatly reduced,<ref name="Nelson"/> with the exception of ''Notopteris'' species, which have a long tail.<ref>{{cite journal|doi=10.1071/AM03013|title=Electrophoretic studies of the systematic and biogeographic relationships of the Fijian bat genera Pteropus, Pteralopex, Chaerephon and Notopteris|journal=[[Australian Mammalogy]]|volume=25|page=13|year=2003|last1=Ingleby|first1=S.|last2=Colgan|first2=D.|doi-access=free}}</ref> Most megabat wings insert laterally (attach to the body directly at the sides). In ''[[Dobsonia]]'' species, the wings attach nearer the spine, giving them the common name of "bare-backed" or "naked-backed" fruit bats.<ref name="Hall"/>

===Skeleton===
====Skull and dentition====
[[File:Pteropus melanotus 04 MWNH 237.jpg|thumb|alt=A bat skull with prominent canines on a white background.|Skull of the [[black-eared flying fox]] (''Pteropus melanotus'')]]
Megabats have large [[Orbit (anatomy)|orbits]], which are bordered by well-developed [[postorbital process]]es posteriorly. The postorbital processes sometimes join to form the [[postorbital bar]]. The [[snout]] is simple in appearance and not highly modified, as is seen in other bat families.<ref>{{cite book|last1=Vaughan| first1=T. A.| last2=Ryan| first2=J. M.| last3=Czaplewski| first3=N. J.|title=Mammalogy| date=11 December 2013| publisher=Jones & Bartlett Publishers| isbn=978-1-284-03218-5| pages=255–256| edition=6|url=https://books.google.com/books?id=GVy2AgAAQBAJ&pg=PA256}}</ref> The length of the snout varies among genera. The [[premaxilla]] is well-developed and usually free,<ref name="Miller, 1907"/> meaning that it is not fused with the [[maxilla]]; instead, it articulates with the maxilla via [[ligament]]s, making it freely movable.<ref>{{cite journal|doi=10.1206/0003-0090(2001)258<0001:PROMBC>2.0.CO;2|issn=0003-0090|year=2001|volume=258|title=Phylogenetic Relationships of Mormoopid Bats (Chiroptera: Mormoopidae) Based on Morphological Data|journal=Bulletin of the American Museum of Natural History|last1=Simmons|first1=Nancy B.|last2=Conway|first2=Tenley M.|hdl=2246/1608|page=17|s2cid=83580917 |url=https://zenodo.org/record/5376511}}</ref><ref>{{cite journal|doi=10.23689/fidgeo-999|year=2011|last1=Lindenau|first1=Christa|title=Middle Pleistocene bats (Mammalia: Chiroptera) from the Yarimburgaz Cave in Turkish Thrace (Turkey)|journal=E&G – Quaternary Science Journal|volume=55|page=127}}</ref> The premaxilla always lack a palatal branch.<ref name="Miller, 1907"/> In species with a longer snout, the skull is usually arched. In genera with shorter faces (''Penthetor'', ''Nyctimene'', ''Dobsonia'', and ''Myonycteris''), the skull has little to no bending.<ref>{{cite journal|url=http://digitallibrary.amnh.org/bitstream/handle/2246/1781/B080a09.pdf;jsessionid=24A463ACFEB3921ED860E6934C4BCE11?sequence=1|title=Results of the Archbold Expeditions No. 48: Pteropodidae (Chiroptera) of the Archbold Collections| last=Tate| first=G. H. H.|year=1942| journal=Bulletin of the American Museum of Natural History| volume=80| pages=332–335}}</ref>

Megabat species have relatively small incisors and large canines. The premolars and molars are adapted to crush and pierce fruit, their primary food source.<ref>Berkovitz, B., & Shellis, P. (2018). The teeth of mammalian vertebrates. Academic Press.</ref>

The most complete dental formula is: I2/2, C{{nbs}}1/1, P3/3, M2/3{{nbs}}×{{nbs}}2 equals{{nbs}}34.<ref>Giannini, N. P., Wible, J. R., & Simmons, N. B. (2006). On the cranial osteology of chiroptera. I. Pteropus (Megachiroptera: Pteropodidae). Bulletin of the American Museum of Natural History, 2006(295), 1–134.</ref> The dental formula of 34 teeth is a homologous trait for megabats.<ref name="Giannini 2007" /> The total number of teeth varies among megabat species, and can range from 24 to 34. For example, some species of megabats have only two molars on either side of the lower jaw instead of three. Others may lack one or more pairs of incisors on the upper or lower jaw.<ref name="Giannini 2007" />

All megabats have two to four each of upper and lower [[incisor]]s, with the exception of [[Bulmer's fruit bat]] (''Aproteles bulmerae''), which completely lacks incisors,<ref name="Giannini 2007" /> and the [[São Tomé collared fruit bat]] (''Myonycteris brachycephala''), which has two upper and three lower incisors.<ref name="Juste 1993">{{cite journal|last1=Juste| first1= J.| last2= Ibáñez| first2= C.| year=1993| title= An asymmetric dental formula in a mammal, the Sao Tomé Island fruit bat Myonycteris brachycephala (Mammalia: Megachiroptera)| journal= [[Canadian Journal of Zoology]]| volume= 71| issue=1| pages= 221–224| doi= 10.1139/z93-030| bibcode= 1993CaJZ...71..221J| hdl= 10261/48798| hdl-access= free}}</ref> This makes it the only mammalian species with an asymmetrical [[dentition#Dental formula|dental formula]].<ref name="Juste 1993" />

All species have two upper and lower [[canine tooth|canine teeth]]. The number of [[premolar]]s is variable, with four or six each of upper and lower premolars.
The first upper and lower [[molar (tooth)|molars]] are always present, meaning that all megabats have at least four molars. The remaining molars may be present, present but reduced, or absent.<ref name="Giannini 2007">{{cite journal|doi=10.1206/0003-0082(2007)3559[1:EHATEO]2.0.CO;2|last1=Giannini| first1= N. P.| last2= Simmons| first2= N. B.| year= 2007| title= Element homology and the evolution of dental formulae in megachiropteran bats (Mammalia: Chiroptera: Pteropodidae)| journal= [[American Museum Novitates]]|issue=3559| pages= 1–27| url=http://digitallibrary.amnh.org/bitstream/handle/2246/5849//v3/dspace/updateIngest/pdfs/N3559.pdf?sequence=1&isAllowed=y|hdl=2246/5849|s2cid=62823404 }}</ref> Megabat molars and premolars are simplified, with a reduction in the [[Cusp (anatomy)|cusps]] and ridges resulting in a more flattened [[crown (tooth)|crown]].<ref name="Wimsatt"/>

Like most mammals, megabats are [[diphyodont]], meaning that the young have a set of [[deciduous teeth]] (milk teeth) that falls out and is replaced by permanent teeth. For most species, there are 20 deciduous teeth. As is typical for mammals,<ref>{{cite journal|last1=Luo| first1= Z. X.| last2= Kielan-Jaworowska| first2=Z.| last3= Cifelli| first3= R. L.| year= 2004| title= Evolution of dental replacement in mammals| journal= Bulletin of Carnegie Museum of Natural History| volume=2004| issue=36| pages=159–176|url=https://pdfs.semanticscholar.org/f49e/b498515c8cf669c24884e66dc55246d0219a.pdf|archive-url=https://web.archive.org/web/20190523184301/https://pdfs.semanticscholar.org/f49e/b498515c8cf669c24884e66dc55246d0219a.pdf|archive-date=2019-05-23| doi= 10.2992/0145-9058(2004)36[159:EODRIM]2.0.CO;2| s2cid= 5630875}}</ref> the deciduous set does not include molars.<ref name="Wimsatt"/>

====Postcrania====
[[File:Pteropus samoensis-3.jpg|thumb|alt=An articulated bat skeleton on a black background.|Skeleton of the [[Samoa flying fox]] (''Pteropus samoensis'')]]
The [[scapula]]e (shoulder blades) of megabats have been described as the most primitive of any chiropteran family.<ref name="Wimsatt"/> The shoulder is overall of simple construction, but has some specialized features. The primitive insertion of the [[omohyoid muscle]] from the [[clavicle]] (collarbone) to the scapula is [[Anatomical terms of location#Medial and lateral|laterally]] displaced (more towards the side of the body)—a feature [[Convergent evolution|also seen]] in the [[Phyllostomidae]]. The shoulder also has a well-developed system of muscular slips (narrow bands of muscle that augment larger muscles) that anchor the tendon of the occipitopollicalis muscle (muscle in bats that runs from base of neck to the base of the thumb)<ref name="Hall">{{cite book| title=Flying Foxes: Fruit and Blossom Bats of Australia| first1=L. S.| last1= Hall| first2= G.| last2= Richards| year=2000| publisher=[[University of New South Wales|UNSW Press]]|isbn=978-0-86840-561-2}}</ref> to the skin.<ref name="Nelson"/>

While microbats only have claws on the [[thumb]]s of their forelimbs, most megabats have a clawed second digit as well;<ref name="Wimsatt">{{cite book|editor-last1=Wimsatt| editor-first1= W.| year=1970| title= Biology of Bats| publisher= [[Academic Press]]| isbn=978-0-323-15119-1|pages=103–136|chapter=Chapter 3: The Skeletal System| last=Vaughan| first=T.}}</ref> only ''Eonycteris'', ''Dobsonia'', ''Notopteris'', and ''Neopteryx'' lack the second claw.<ref name="Nowak">{{cite book|first1=R. M.| last1= Nowak| first2= E.| last2= Pillsbury Walker| year=1999|title=Walker's Mammals of the World| volume=1| publisher=JHU Press| isbn=978-0-8018-5789-8|page=258}}</ref> The first digit is the shortest, while the third digit is the longest. The second digit is incapable of [[flexion]].<ref name="Wimsatt"/> Megabats' thumbs are longer relative to their forelimbs than those of microbats.<ref name="Hall"/>

Megabats' hindlimbs have the same skeletal components as humans. Most megabat species have an additional structure called the [[calcar]], a cartilage spur arising from the [[calcaneus]].<ref name="Bennett"/> Some authors alternately refer to this structure as the uropatagial spur to differentiate it from microbats' calcars, which are structured differently. The structure exists to stabilize the uropatagium, allowing bats to adjust the [[Camber (aerodynamics)|camber]] of the membrane during flight. Megabats lacking the calcar or spur include ''Notopteris'', ''Syconycteris'', and ''[[Harpyionycteris]]''.<ref>{{cite journal|doi=10.1023/A:1020566902992|year=1998|last1=Schutt|first1=W. A.|journal=[[Journal of Mammalian Evolution]]|volume=5|page=2|last2=Simmons|first2=N. B.| title=Morphology and Homology of the Chiropteran Calca, with Comments on the Phylogenetic Relationships of ''Archaeopteropus''|s2cid=20426664}}</ref> The entire leg is rotated at the hip compared to normal mammal orientation, meaning that the knees face [[Anatomical terms of location#Anterior and posterior|posteriorly]]. All five digits of the foot flex in the direction of the [[sagittal plane]], with no digit capable of flexing in the opposite direction, as in the feet of perching birds.<ref name="Bennett">{{cite journal|doi=10.1111/j.1469-7998.1993.tb02633.x|title=Structural modifications involved in the fore- and hind limb grip of some flying foxes (Chiroptera: Pteropodidae)|journal=[[Journal of Zoology]]|volume=229|issue=2|pages=237–248|year=1993|last1=Bennett|first1=M. B.}}</ref>

===Internal systems===
[[File:Hypsignathus monstrosus anatomy.png|thumb|alt=A scientific illustration of the internal anatomy of a megabat. Its organs are individually labeled.|Internal anatomy of the [[hammer-headed bat]] (''Hypsignathus monstrosus'')]]
Flight is very energetically expensive, requiring several adaptations to the [[cardiovascular system]]. During flight, bats can raise their [[oxygen consumption]] by twenty times or more for sustained periods; human athletes can achieve an increase of a factor of twenty for a few minutes at most.<ref name="Maina">{{cite journal|url=http://jeb.biologists.org/content/jexbio/111/1/43.full.pdf| title=Correlations between structure and function in the design of the bat lung: a morphometric study| first1=J. N.| last1= Maina| first2= A. S.| last2= King| journal=[[Journal of Experimental Biology]]| year= 1984| volume= 11| issue=1| page=44| doi=10.1242/jeb.111.1.43| pmid=6491593| bibcode=1984JExpB.111...43M}}</ref> A 1994 study of the [[straw-coloured fruit bat]] (''Eidolon helvum'') and [[hammer-headed bat]] (''Hypsignathus monstrosus'') found a mean [[respiratory exchange ratio]] (carbon dioxide produced:oxygen used) of approximately 0.78. Among these two species, the [[gray-headed flying fox]] (''Pteropus poliocephalus'') and the [[Egyptian fruit bat]] (''Rousettus aegyptiacus''), maximum heart rates in flight varied between 476 beats per minute (gray-headed flying fox) and 728 beats per minute (Egyptian fruit bat). The maximum number of breaths per minute ranged from 163 (gray-headed flying fox) to 316 (straw-colored fruit bat).<ref>{{cite journal|url=http://jeb.biologists.org/content/jexbio/120/1/79.full.pdf| title=Flight Physiology of Intermediate-Sized Fruit Bats (Pteropodidae)| journal=Journal of Experimental Biology|year= 1986| volume= 120| pages= 84–93|first=R. E.| last=Carpenter| issue=1| doi=10.1242/jeb.120.1.79| bibcode=1986JExpB.120...79C}}</ref> Additionally, megabats have exceptionally large [[lung volumes]] relative to their sizes. While terrestrial mammals such as [[shrew]]s have a lung volume of 0.03&nbsp;cm<sup>3</sup> per gram of body weight (0.05&nbsp;in<sup>3</sup> per ounce of body weight), species such as the [[Wahlberg's epauletted fruit bat]] (''Epomophorus wahlbergi'') have lung volumes 4.3 times greater at 0.13&nbsp;cm<sup>3</sup> per gram (0.22&nbsp;in<sup>3</sup> per ounce).<ref name="Maina"/>

Megabats have rapid digestive systems, with a gut transit time of half an hour or less.<ref name="Nelson">{{cite report|url=https://www.environment.gov.au/system/files/pages/a117ced5-9a94-4586-afdb-1f333618e1e3/files/37-ind.pdf| title=Fauna of Australia| last=Nelson| first=J. E.| volume=1B|publisher=[[Department of the Environment and Energy|Australian Government Department of the Environment and Energy]]}}</ref> The digestive system is structured to a [[herbivorous]] diet sometimes restricted to soft fruit or nectar.<ref name="Richards1983" /> The length of the digestive system is short for a herbivore (as well as shorter than those of [[insectivorous]] microchiropterans),<ref name="Richards1983"/> as the fibrous content is mostly separated by the action of the palate, tongue, and teeth, and then discarded.<ref name="Richards1983" /> Many megabats have U-shaped stomachs. There is no distinct difference between the small and large intestine, nor a distinct beginning of the [[rectum]]. They have very high densities of intestinal [[microvillus|microvilli]], which creates a large surface area for the absorption of nutrients.<ref>{{cite book| title=Comparative Anatomy of the Gastrointestinal Tract in Eutheria II| editor-first=A.| editor-last= Schmidt-Rhaesa| isbn=978-3-11-056067-1| publisher=[[Walter de Gruyter GmbH & Co KG]]| year=2017|pages=328–330}}</ref>

==Biology and ecology==
===Genome size===
Like all bats, megabats have much smaller [[genome]]s than other mammals. A 2009 study of 43 megabat species found that their genomes ranged from 1.86 picograms (pg, 978 Mbp per pg) in the straw-colored fruit bat to 2.51 pg in [[Lyle's flying fox]] (''Pteropus lylei''). All values were much lower than the mammalian average of 3.5 pg. Megabats have even smaller genomes than microbats, with a mean weight of 2.20 pg compared to 2.58 pg. It was speculated that this difference could be related to the fact that the megabat lineage has experienced an extinction of the [[LINE1]]—a type of [[long interspersed nuclear element]]. LINE1 constitutes 15–20% of the human genome and is considered the most prevalent long interspersed nuclear element among mammals.<ref>{{cite journal|doi=10.1098/rsbl.2009.0016|pmid=19324635|pmc=2679926|title=The genome sizes of megabats (Chiroptera: Pteropodidae) are remarkably constrained|journal=[[Biology Letters]]|volume=5|issue=3|pages=347–351|year=2009|last1=Smith|first1=J. D. L.|last2=Gregory|first2=T. R.}}</ref>

===Senses===
====Sight====
[[File:1977.05.03 Fijian Monkey-faced Bat ,Taveuni, Fiji 3443 ccccr.jpg|thumb|alt=A headshot of a bat with orangish-brown fur looking directly at the camera. Its eyes are piercingly orange.|The reddish-orange eyes of the [[Fijian monkey-faced bat]] (''Mirimiri acrodonta'')]]
With very few exceptions, megabats do not [[Animal echolocation|echolocate]], and therefore rely on sight and smell to navigate.<ref name="Muller"/> They have large eyes positioned at the front of their heads.<ref name="Graydon"/> These are larger than those of the common ancestor of all bats, with one study suggesting a trend of increasing eye size among pteropodids. A study that examined the eyes of 18 megabat species determined that the [[common blossom bat]] (''Syconycteris australis'') had the smallest eyes at a diameter of {{cvt|5.03|mm|in}}, while the largest eyes were those of [[large flying fox]] (''Pteropus vampyrus'') at {{cvt|12.34|mm|in}} in diameter.<ref>{{cite journal|doi=10.1038/s41467-017-02532-x|pmid=29311648|pmc=5758785|title=Auditory opportunity and visual constraint enabled the evolution of echolocation in bats|journal=Nature Communications|volume=9|issue=1|page=98|year=2018|last1=Thiagavel|first1=J.|last2=Cechetto|first2=C.|last3=Santana|first3=S. E.|last4=Jakobsen|first4=L.|last5=Warrant|first5=E. J.|last6=Ratcliffe|first6=J. M.|bibcode=2018NatCo...9...98T}}</ref> Megabat irises are usually brown, but they can be red or orange, as in ''[[Desmalopex]]'', ''[[Mirimiri]]'', ''[[Pteralopex]]'', and some ''Pteropus''.<ref>{{cite journal|doi=10.3161/150811008X331054|title=The systematic position of Pteropus leucopterus and its bearing on the monophyly and relationships of Pteropus (Chiroptera: Pteropodidae)|journal=Acta Chiropterologica|volume=10|pages=11–20|year=2008|last1=Giannini|first1=N. P.|last2=Almeida|first2=F. C.|last3=Simmons|first3=N. B.|last4=Helgen|first4=K. M.|hdl=11336/82001|s2cid=59028595|hdl-access=free}}</ref>

At high brightness levels, megabat [[visual acuity]] is poorer than that of humans; at low brightness it is superior.<ref name="Graydon">{{cite journal|journal=[[Journal of the Australian Mammal Society]]| pages=101–105| url=https://books.google.com/books?id=yENMUzuisWwC&pg=RA1-PA101| title=Vision in Flying-Foxes (Chiroptera:Pteropodidae)| volume=10| issue=2| year=1987| last1=Graydon| first1=M.| last2=Giorgi| first2=P.| last3=Pettigrew| first3=J.| doi=10.1071/AM87021| s2cid=254716342| url-access=subscription}}</ref> One study that examined the eyes of some ''Rousettus'', ''Epomophorus'', ''Eidolon'', and ''Pteropus'' species determined that the first three genera possess a ''[[tapetum lucidum]]'', a reflective structure in the eyes that improves vision at low light levels, while the ''Pteropus'' species do not.<ref name="Muller"/> All species examined had [[retina]]e with both [[rod cell]]s and [[cone cell]]s, but only the ''Pteropus'' species had S-cones, which detect the shortest wavelengths of light; because the spectral tuning of the [[opsin]]s was not discernible, it is unclear whether the S-cones of ''Pteropus'' species detect blue or ultraviolet light. ''Pteropus'' bats are [[Dichromacy|dichromatic]], possessing two kinds of cone cells. The other three genera, with their lack of S-cones, are [[Monochromacy|monochromatic]], unable to see color. All genera had very high densities of rod cells, resulting in high sensitivity to light, which corresponds with their nocturnal activity patterns. In ''Pteropus'' and ''Rousettus'', measured rod cell densities were 350,000–800,000 per square millimeter, equal to or exceeding other nocturnal or [[crepuscular]] animals such as the [[house mouse]], [[domestic cat]], and [[domestic rabbit]].<ref name="Muller">{{cite journal|doi=10.1159/000102971|pmid=17522478|title=Cone Photoreceptor Diversity in the Retinas of Fruit Bats (Megachiroptera)|journal=[[Brain, Behavior and Evolution]]|volume=70|issue=2|pages=90–104|year=2007|last1=Müller|first1=B.|last2=Goodman|first2=S. M.|last3=Peichl|first3=Leo|s2cid=29095435}}</ref>

====Smell====
[[File:EB1911 Chiroptera Fig. 5.jpg|thumb|alt=A scientific illustration of a megabat face in profile with prominent nostrils. Each nostril is a distinct tube projecting away from the face at a right angle.|The nostrils of the [[island tube-nosed fruit bat]] (''Nyctimene major'')]]
Megabats use smell to find food sources like fruit and nectar.<ref name="Jones"/> They have keen senses of smell that rival that of the [[domestic dog]].<ref name="Schwab">{{cite journal|doi=10.1136/bjo.2005.077966|pmid=16267906|pmc=1772916|title=A choroidal sleight of hand|journal=[[British Journal of Ophthalmology]]|volume=89|issue=11|page=1398|year=2005|last1=Schwab|first1=I. R.}}</ref> Tube-nosed fruit bats such as the [[eastern tube-nosed bat]] (''Nyctimene robinsoni'') have stereo [[olfaction]], meaning they are able to map and follow odor plumes three-dimensionally.<ref name="Schwab"/>
Along with most (or perhaps all) other bat species, megabats mothers and offspring also use scent to recognize each other, as well as for recognition of individuals.<ref name="Jones">{{cite journal|doi=10.3389/fphys.2013.00117|pmid=23755015|pmc=3667242|title=From the ultrasonic to the infrared: Molecular evolution and the sensory biology of bats|journal=[[Frontiers in Physiology]]|volume=4|page=117|year=2013|last1=Jones|first1=G.|last2=Teeling|first2=E. C.|last3=Rossiter|first3=S. J.|doi-access=free}}</ref> In flying foxes, males have enlarged [[androgen]]-sensitive [[sebaceous gland]]s on their shoulders they use for [[Territory (animal)#Spraying|scent-marking]] their territories, particularly during the mating season. The secretions of these glands vary by species—of the 65 chemical compounds isolated from the glands of four species, no compound was found in all species.<ref name="Wood 2005"/> Males also engage in [[Urination#Other animals|urine washing]], or coating themselves in their own urine.<ref name="Wood 2005">{{cite journal| last1=Wood| first1= W. F.| last2= Walsh| first2= A.| last3= Seyjagat| first3= J.| last4= Weldon| first4= P. J.| title= Volatile Compounds in Shoulder Gland Secretions of Male Flying Foxes, Genus Pteropus (Pteropodidae, Chiroptera)| year=2005| journal=[[Z Naturforsch C]]| volume=60| issue=9–10| pages= 779–784|url=https://www.researchgate.net/publication/7447695| doi= 10.1515/znc-2005-9-1019| pmid= 16320623| s2cid= 1938648| doi-access= free}}</ref><ref name="Wagner 2008">{{cite journal| last=Wagner| first= J.| year=2008| title= Glandular secretions of male Pteropus (Flying foxes): preliminary chemical comparisons among species|journal=Independent Study Project (Isp) Collection| url=http://digitalcollections.sit.edu/isp_collection/559/}}</ref>

====Taste====
Megabats possess the ''[[TAS1R2]]'' gene, meaning they have the ability to detect sweetness in foods. This gene is present among all bats except [[vampire bat]]s. Like all other bats, megabats cannot taste ''[[umami]]'', due to the absence of the ''[[TAS1R1]]'' gene. Among other mammals, only [[giant panda]]s have been shown to lack this gene.<ref name="Jones"/> Megabats also have multiple ''TAS2R'' genes, indicating that they can taste bitterness.<ref>{{cite journal|doi=10.1093/molbev/mst219|pmid=24202612|pmc=3907052|title=Diet Shapes the Evolution of the Vertebrate Bitter Taste Receptor Gene Repertoire|journal=[[Molecular Biology and Evolution]]|volume=31|issue=2|pages=303–309|year=2014|last1=Li|first1=D.|last2=Zhang|first2=J.}}</ref>

===Reproduction and life cycle===
[[File:Pteropus lylei.jpg|thumb|alt=A female flying fox faces the camera with her wings slightly outstretched. A young flying fox clings to her abdomen, looking at the camera with its eyes open. The mother's eyes are closed and her face is next to her offspring's.|A [[Lyle's flying fox]] (''Pteropus lylei'') with offspring]]
Megabats, like all bats, are long-lived relative to their size for mammals. Some captive megabats have had lifespans exceeding thirty years.<ref name="Nowak"/> Relative to their sizes, megabats have low reproductive outputs and delayed sexual maturity, with females of most species not giving birth until the age of one or two.<ref name="Mickleburgh"/>{{rp|6}} Some megabats appear to be able to breed throughout the year, but the majority of species are likely [[seasonal breeder]]s.<ref name="Nowak"/> Mating occurs at the roost.<ref>{{Cite journal| doi = 10.1292/jvms.17-0329| pmid = 28804092| pmc = 5658557| volume = 79| issue = 10| pages = 1667–1674| last1 = Hengjan| first1 = Yupadee| last2 = Iida| first2 = Keisuke| last3 = Doysabas| first3 = Karla Cristine C.| last4 = Phichitrasilp| first4 = Thanmaporn| last5 = Ohmori| first5 = Yasushige| last6 = Hondo| first6 = Eiichi| title = Diurnal behavior and activity budget of the golden-crowned flying fox (''Acerodon jubatus'') in the Subic bay forest reserve area, the Philippines| journal = Journal of Veterinary Medical Science| date = 2017}}</ref> Gestation length is variable,<ref name="Heideman"/> but is four to six months in most species. Different species of megabats have reproductive adaptations that lengthen the period between copulation and giving birth. Some species such as the straw-colored fruit bat have the reproductive adaptation of [[delayed implantation]], meaning that copulation occurs in June or July, but the [[zygote]] does not implant into the [[uterus|uterine]] wall until months later in November.<ref name="Mickleburgh"/>{{rp|6}} The [[Fischer's pygmy fruit bat]] (''Haplonycteris fischeri''), with the adaptation of post-implantation delay, has the longest gestation length of any bat species, at up to 11.5 months.<ref name="Heideman">{{cite journal|doi=10.1111/j.1469-7998.1988.tb02396.x|title=The timing of reproduction in the fruit bat ''Haplonycteris fischeri'' (Pteropodidae): Geographic variation and delayed development|journal=Journal of Zoology|volume=215|issue=4|pages=577–595|year=1988|last1=Heideman|first1=P. D.|hdl=2027.42/72984|hdl-access=free}}</ref> The post-implantation delay means that development of the embryo is suspended for up to eight months after implantation in the uterine wall, which is responsible for its very long pregnancies.<ref name="Mickleburgh"/>{{rp|6}} Shorter gestation lengths are found in the [[greater short-nosed fruit bat]] (''Cynopterus sphinx'') with a period of three months.<ref>{{cite book|first1=R. M.| last1= Nowak| first2= E.| last2= Pillsbury Walker| year=1999|title=Walker's Mammals of the World| volume=1| publisher=JHU Press| isbn=978-0-8018-5789-8|page=287}}</ref>

The litter size of all megabats is usually one.<ref name="Mickleburgh">{{cite report|url=https://portals.iucn.org/library/efiles/documents/1992-034.pdf|last1=Mickleburgh| first1= S. P.| last2= Hutson| first2= A. M.| last3= Racey| first3= P. A.| year= 1992| title= Old World fruit bats: An action plan for their conservation| location= Gland, Switzerland| publisher= [[IUCN]]}}</ref>{{rp|6}} There are scarce records of twins in the following species: [[Madagascan flying fox]] (''Pteropus rufus''), [[Dobson's epauletted fruit bat]] (''Epomops dobsoni''), the gray-headed flying fox, the [[black flying fox]] (''Pteropus alecto''), the [[spectacled flying fox]] (''Pteropus conspicillatus''),<ref name="Fox">{{Cite journal| doi = 10.3161/150811008X414845| volume = 10| issue = 2| pages = 271–278| last1 = Fox| first1 = Samantha| last2 = Spencer| first2 = Hugh| last3 = O'Brien| first3 = Gemma M.| title = Analysis of twinning in flying-foxes (Megachiroptera) reveals superfoetation and multiple-paternity| journal = Acta Chiropterologica| date = 2008| s2cid = 83506361}}</ref> the greater short-nosed fruit bat,<ref>{{Cite journal| doi = 10.2307/1379269| volume = 55| issue = 1| pages = 200–202| last1 = Sreenivasan| first1 = M. A.| last2 = Bhat| first2 = H. R.| last3 = Geevarghese| first3 = G.| title = Observations on the Reproductive Cycle of Cynopterus sphinx sphinx Vahl, 1797 (Chiroptera: Pteropidae)| journal = Journal of Mammalogy| date = 1974-03-30| jstor = 1379269| pmid = 4819592}}</ref> [[Peters's epauletted fruit bat]] (''Epomophorus crypturus''), the hammer-headed bat, the straw-colored fruit bat, the [[little collared fruit bat]] (''Myonycteris torquata''), the Egyptian fruit bat, and [[Leschenault's rousette]] (''Rousettus leschenaultii'').<ref name="Douglass"/>{{rp|85–87}} In the cases of twins, it is rare that both offspring survive.<ref name="Fox"/> Because megabats, like all bats, have low reproductive rates, their populations are slow to recover from declines.<ref>{{Cite book| edition = 2nd| publisher = Oxford University Press| isbn = 978-0-19-920711-4| last1 = Altringham| first1 = John D.| last2 = McOwat| first2 = Tom| last3 = Hammond| first3 = Lucy| title = Bats: from evolution to conservation| location = Oxford and New York| date = 2011|page=xv}}</ref>

At birth, megabat offspring are, on average, 17.5% of their mother's post-partum weight. This is the smallest offspring-to-mother ratio for any bat family; across all bats, newborns are 22.3% of their mother's post-partum weight. Megabat offspring are not easily categorized into the traditional categories of [[altricial]] (helpless at birth) or [[precocial]] (capable at birth). Species such as the greater short-nosed fruit bat are born with their eyes open (a sign of precocial offspring), whereas the Egyptian fruit bat offspring's eyes do not open until nine days after birth (a sign of altricial offspring).<ref name="Kunz 1987">{{cite journal|last1=Kunz| first1= T. H.| last2= Kurta| first2= A.| year=1987| title= Size of bats at birth and maternal investment during pregnancy| journal= Symposia of the Zoological Society of London| volume=57| url=http://www.bu.edu/cecb/files/2009/08/Symp.pdf}}</ref>

As with nearly all bat species, males do not assist females in parental care.<ref name="Safi 2008">{{cite journal|doi=10.1644/08-MAMM-S-058.1|title=Social Bats: The Males' Perspective|journal=[[Journal of Mammalogy]]|volume=89|issue=6|pages=1342–1350|year=2008|last1=Safi|first1=K.|bibcode=2008JMamm..89.1342S |s2cid=85733862|doi-access=free}}</ref>
The young stay with their mothers until they are [[Weaning|weaned]]; how long weaning takes varies throughout the family. Megabats, like all bats, have relatively long nursing periods: offspring will nurse until they are approximately 71% of adult body mass, compared to 40% of adult body mass in non-bat mammals.<ref>{{cite book|title=Reproductive Biology of Bats|url=https://archive.org/details/reproductivebiol00cric_666|url-access=limited| editor1-first=E. G.| editor1-last= Crichton| editor2-first= P. H.|editor2-last= Krutzsch| page=[https://archive.org/details/reproductivebiol00cric_666/page/n445 433]| publisher=Academic Press| year=2000| isbn=978-0-08-054053-5}}</ref> Species in the genus ''[[Micropteropus]]'' wean their young by seven to eight weeks of age, whereas the [[Indian flying fox]] (''Pteropus medius'') does not wean its young until five months of age.<ref name="Douglass">{{cite book|url=https://books.google.com/books?id=yQzSe71g2AcC&pg=PA89| title=Asdell's Patterns of Mammalian Reproduction: A Compendium of Species-specific Data| first1=V.| last1= Douglass Hayssen| first2= A.| last2= Van Tienhoven| first3= A.| last3= Van Tienhoven| year=1993| publisher=[[Cornell University Press]]| isbn=978-0-8014-1753-5|page=89}}</ref> Very unusually, male individuals of two megabat species, the [[Bismarck masked flying fox]] (''Pteropus capistratus'') and the [[Dayak fruit bat]] (''Dyacopterus spadiceus''), have been observed [[male lactation|producing milk]], but there has never been an observation of a male nursing young.<ref>{{cite journal|doi=10.1016/j.tree.2009.03.008|pmid=19427057|title=Galactorrhoea is not lactation|journal=[[Trends in Ecology & Evolution]]|volume=24|issue=7|pages=354–355|year=2009|last1=Racey|first1=D. N.|last2=Peaker|first2=M.|last3=Racey|first3=P. A.|bibcode=2009TEcoE..24..354R }}</ref> It is unclear if the lactation is functional and males actually nurse pups or if it is a result of [[stress (biology)|stress]] or [[malnutrition]].<ref name="Kunz 2009">{{cite journal|doi=10.1016/j.tree.2008.09.009|pmid=19100649|title=Male lactation: Why, why not and is it care?|journal=Trends in Ecology & Evolution|volume=24|issue=2|pages=80–85|year=2009|last1=Kunz|first1=T. H|last2=Hosken|first2=David J|bibcode=2009TEcoE..24...80K }}</ref>

===Behavior and social systems===
[[File:Flying foxes.png|thumb|alt=A colony of megabats roosting in a tree during the daytime. They appear as black shapes evenly dispersed throughout the canopy of the tree.|A group of roosting megabats of the genus ''Pteropus'']]
Many megabat species are highly [[gregarious]] or social. Megabats will vocalize to communicate with each other, creating noises described as "trill-like bursts of sound",<ref>{{cite journal|doi=10.3161/150811012X661729|title=Vocalizations in the Malagasy Cave-Dwelling Fruit Bat, Eidolon dupreanum: Possible Evidence of Incipient Echolocation?|last1=Schoeman| first1= M. C.| last2= Goodman| first2= S. M. |journal=Acta Chiropterologica|volume=14|issue=2|page=409|year=2012|s2cid=86613252}}</ref> honking,<ref>{{cite magazine|url=http://www.batcon.org/resources/media-education/bats-magazine/bat_article/1500| title=Hammer-headed Fruit Bat| volume=34| issue=1| magazine=BATS Magazine| year=2015| access-date=30 May 2019}}</ref> or loud, bleat-like calls<ref>{{cite journal|doi=10.1093/mspecies/sex007|title=Nyctimene robinsoni (Chiroptera: Pteropodidae)|journal=[[Mammalian Species]]|volume=49|issue=949|pages=68–75|year=2017|last1=Loveless|first1=A. M.|last2=McBee|first2=K.|s2cid=89828640|doi-access=free}}</ref> in various genera. At least one species, the Egyptian fruit bat, is capable of a kind of [[vocal learning]] called vocal production learning, defined as "the ability to modify vocalizations in response to interactions with conspecifics".<ref>{{Cite journal|last1=Prat|first1=Yosef|last2=Taub|first2=Mor|last3=Yovel|first3=Yossi|date=2015|title=Vocal learning in a social mammal: Demonstrated by isolation and playback experiments in bats|journal=Science Advances|language=en|volume=1|issue=2|article-number=e1500019|doi=10.1126/sciadv.1500019|issn=2375-2548|pmc=4643821|pmid=26601149|bibcode=2015SciA....1E0019P}}</ref><ref>{{cite journal|doi=10.3758/s13423-016-1060-3|pmid=27368623|pmc=5325843|title=What bats have to say about speech and language|journal=[[Psychonomic Bulletin & Review]]|volume=24|issue=1|pages=111–117|year=2017|last1=Vernes|first1=S. C.}}</ref> Young Egyptian fruit bats are capable of acquiring a [[dialect]] by listening to their mothers, as well as other individuals in their colonies. It has been postulated that these dialect differences may result in individuals of different colonies communicating at different frequencies, for instance.<ref>{{Cite journal|last1=Prat|first1=Yosef|last2=Azoulay|first2=Lindsay|last3=Dor|first3=Roi|last4=Yovel|first4=Yossi|date=2017|title=Crowd vocal learning induces vocal dialects in bats: Playback of conspecifics shapes fundamental frequency usage by pups|journal=PLOS Biology|language=en|volume=15|issue=10|article-number=e2002556|doi=10.1371/journal.pbio.2002556|issn=1545-7885|pmc=5663327|pmid=29088225 |doi-access=free }}</ref><ref>{{cite web|url=https://www.the-scientist.com/notebook/what-bat-quarrels-tell-us-about-vocal-learning-30141| title=What Bat Quarrels Tell Us About Vocal Learning| last=Zimmer| first=K.| date=1 January 2018| access-date=23 May 2019|website=The Scientist}}</ref>

Megabat social behavior includes using sexual behaviors for more than just reproduction. Evidence suggests that female Egyptian fruit bats take food from males in exchange for sex. Paternity tests confirmed that the males from which each female scrounged food had a greater likelihood of fathering the scrounging female's offspring.<ref>{{cite journal|doi=10.1016/j.cub.2019.04.066|pmid=31130455|title=Food for Sex in Bats Revealed as Producer Males Reproduce with Scrounging Females|journal=Current Biology|volume=29|issue=11|pages=1895–1900.e3|year=2019|last1=Harten|first1=L.|last2=Prat|first2=Y.|last3=Ben Cohen|first3=S.|last4=Dor|first4=R.|last5=Yovel|first5=Y.|s2cid=162183551|doi-access=free|bibcode=2019CBio...29E1895H }}</ref>
Homosexual fellatio has been observed in at least one species, the [[Bonin flying fox]] (''Pteropus pselaphon'').<ref name="Sugita 2016">{{cite journal|doi=10.1371/journal.pone.0166024|pmid=27824953|pmc=5100941|title=Homosexual Fellatio: Erect Penis Licking between Male Bonin Flying Foxes Pteropus pselaphon|journal=PLOS ONE|volume=11|issue=11|article-number=e0166024|year=2016|last1=Sugita|first1=N.|bibcode=2016PLoSO..1166024S|doi-access=free}}</ref><ref name="Tan 2009">{{cite journal|doi=10.1371/journal.pone.0007595|pmid=19862320|pmc=2762080|title=Fellatio by Fruit Bats Prolongs Copulation Time|journal=PLOS ONE|volume=4|issue=10|article-number=e7595|year=2009|last1=Tan|first1=M.|last2=Jones|first2=G.|last3=Zhu|first3=G.|last4=Ye|first4=J.|last5=Hong|first5=T. |last6=Zhou|first6=S. |last7=Zhang|first7=S. |last8=Zhang|first8=L. |bibcode=2009PLoSO...4.7595T|doi-access=free}}</ref> This same-sex fellatio is hypothesized to encourage colony formation of otherwise-antagonistic males in colder climates.<ref name="Sugita 2016"/><ref name="Tan 2009"/>

Megabats are mostly [[nocturnal]] and [[crepuscular]], though some have been observed flying during the day.<ref name="Nowak 1994">{{cite book| last1= Nowak| first1= R. M.| last2= Walker| first2= E. P.| last3= Kunz| first3= T. H.| last4= Pierson| first4= E. D.| year= 1994| title= Walker's bats of the world| publisher= JHU Press| page= [https://archive.org/details/walkersbatsofwor00rona/page/49 49]| isbn= 978-0-8018-4986-2| url-access= registration| url= https://archive.org/details/walkersbatsofwor00rona/page/49}}</ref> A few island species and subspecies are [[diurnality|diurnal]], hypothesized as a response to a lack of [[predators]].
Diurnal taxa include a subspecies of the [[black-eared flying fox]] (''Pteropus melanotus natalis''), the [[Mauritian flying fox]] (''Pteropus niger''), the [[Caroline flying fox]] (''Pteropus molossinus''), a subspecies of ''[[Pteropus pelagicus]]'' (''P. p. insularis''), and the [[Seychelles fruit bat]] (''Pteropus seychellensis'').<ref name="Pierson 1992"/>{{rp|9}}

====Roosting====
A 1992 summary of forty-one megabat genera noted that twenty-nine are tree-roosting genera. A further eleven genera roost in caves, and the remaining six genera roost in other kinds of sites (human structures, mines, and crevices, for example). Tree-roosting species can be solitary or highly [[colony (biology)|colonial]], forming aggregations of up to one million individuals. Cave-roosting species form aggregations ranging from ten individuals up to several thousand. Highly colonial species often exhibit roost fidelity, meaning that their trees or caves may be used as roosts for many years. Solitary species or those that aggregate in smaller numbers have less fidelity to their roosts.<ref name="Mickleburgh"/>{{rp|2}}

===Diet and foraging===
[[File:Eye contact with flying fox.jpg|thumb|upright=1.2|alt=A flying fox with reddish-yellow fur and a dark brown snout is in flight facing the viewer. The background is white.|[[Indian flying fox]] (''Pteropus medius'') in flight]]
Most megabats are primarily [[frugivore|frugivorous]].<ref name="Dumont"/> Throughout the family, a diverse array of fruit is consumed from nearly 188 plant genera.<ref name="Yin"/> Some species are also [[nectarivore|nectarivorous]], meaning that they also drink nectar from flowers.<ref name="Dumont">{{cite journal|doi=10.1644/BOS-107|title=Food Hardness and Feeding Behavior in Old World Fruit Bats (Pteropodidae)|journal=Journal of Mammalogy|volume=85|pages=8–14|year=2004|last1=Dumont|first1=E. R.|last2=O'Neal|first2=R.|s2cid=27275791|doi-access=free}}</ref> In Australia, ''[[Eucalyptus]]'' flowers are an especially important food source.<ref name="Nelson"/> Other food resources include leaves, shoots, buds, pollen, seed pods, sap, cones, bark, and twigs.<ref>{{cite journal|doi=10.1046/j.1365-2907.1998.00033.x|title=Dietary strategies of Old World Fruit Bats (Megachiroptera, Pteropodidae): How do they obtain sufficient protein?|journal=[[Mammal Review]]|volume=28|issue=4|pages=185–194|year=1998|last1=Courts|first1=S. E.|doi-access=free|bibcode=1998MamRv..28..185C }}</ref> They are prodigious eaters and can consume up to 2.5 times their own body weight in fruit per night.<ref name="Yin">{{cite journal|doi=10.1371/journal.pone.0146274|pmid=26735303|pmc=4703304|title=Molecular Evolution of the Nuclear Factor (Erythroid-Derived 2)-Like 2 Gene Nrf2 in Old World Fruit Bats (Chiroptera: Pteropodidae)|journal=PLOS ONE|volume=11|issue=1|article-number=e0146274|year=2016|last1=Yin|first1=Q.|last2=Zhu|first2=L.|last3=Liu|first3=D.|last4=Irwin|first4=D. M.|last5=Zhang|first5=S.|last6=Pan|first6=Y.|bibcode=2016PLoSO..1146274Y|doi-access=free}}</ref>

Megabats fly to roosting and foraging resources. They typically fly straight and relatively fast for bats; some species are slower with greater maneuverability. Species can commute {{cvt|20–50|km|mi}} in a night. [[animal migration|Migratory species]] of the genera ''Eidolon'', ''Pteropus'', ''Epomophorus'', ''Rousettus'', ''Myonycteris'', and ''Nanonycteris'' can migrate distances up to {{cvt|750|km|mi}}. Most megabats have below-average [[Bat flight#Aspect ratio|aspect ratios]],<ref name=Norberg1987>{{cite journal |author1=Norberg, U.M.  |author2=Rayner, J.M.V.  |name-list-style=amp | date = 1987 | title = Ecological morphology and flight in bats (Mammalia: Chiroptera): wing adaptations, flight performance, foraging strategy and echolocation | journal = Philosophical Transactions of the Royal Society B  | volume = 316 | issue = 1179 | pages = 382–383 | doi = 10.1098/rstb.1987.0030|bibcode=1987RSPTB.316..335N }}</ref> which is measurement relating wingspan and wing area.<ref name=Norberg1987/>{{rp|348}} Wing loading, which measures weight relative to wing area,<ref name=Norberg1987/>{{rp|348}} is average or higher than average in megabats.<ref name=Norberg1987/>

For the Cypriot population of ''Rousettus aegyptiacus'', assessing diet plays a key role in defining appropriate conservation measures and reducing conflicts with agriculture.<ref name="Vaglio-2011">{{Cite journal |last1=Vaglio |first1=Maria Alessandra del |last2=Nicolau |first2=Haris |last3=Bosso |first3=Luciano |last4=Russo |first4=Danilo |date=2011-11-08 |title=Feeding habits of the Egyptian fruit bat Rousettus aegyptiacus on Cyprus island: a first assessment |url=http://www.italian-journal-of-mammalogy.it/Feeding-habits-of-the-Egyptian-fruit-bat-Rousettus-aegyptiacus-on-Cyprus-island-a,77284,0,2.html |journal=Hystrix: The Italian Journal of Mammalogy |language=english |volume=22 |issue=2 |doi=10.4404/hystrix-22.2-4587 |issn=0394-1914}}</ref> A study on the island provided the first systematic analysis of the species' feeding habits, mainly through the examination of fruit remains found in droppings. Researchers collected 222 droppings from two cave roosts monitored over three different seasons.<ref name="Vaglio-2011" /> The analysis revealed 11 plant species belonging to 8 botanical families. The most frequent components of the diet were ''Melia azedarach'', ''Morus'' spp., and ''Ceratonia siliqua.'' Other species, such as ''Eriobotrya japonica'', ''Ficus'' spp., and ''Arbutus andrachne'', played an intermediate role in the diet, while the remaining taxa appeared less common.<ref name="Vaglio-2011" />

====Seed dispersal====
Megabats play an important role in [[seed dispersal]].<ref name="Vaglio-2011" />  As a result of their long evolutionary history, some plants have evolved characteristics compatible with bat senses, including fruits that are strongly scented, brightly colored, and prominently exposed away from foliage. The bright colors and positioning of the fruit may reflect megabats' reliance on visual cues and inability to navigate through clutter. In a study that examined the fruits of more than forty fig species, only one fig species was consumed by both birds and megabats; most species are consumed by one or the other. Bird-consumed figs are frequently red or orange, while megabat-consumed figs are often yellow or green.<ref>{{cite journal|doi=10.1111/j.1744-7429.2003.tb00606.x|title=Fruit Bats (Chiroptera: Pteropodidae) as Seed Dispersers and Pollinators in a Lowland Malaysian Rain Forest1|journal=[[Biotropica]]|volume=35|issue=4|pages=491–502|year=2003|last1=Hodgkison|first1=R. |last2=Balding|first2=S. T.|last3=Zubaid|first3=A. |last4=Kunz|first4=T. H.|bibcode=2003Biotr..35..491H |s2cid=86327074}}</ref> Most seeds are excreted shortly after consumption due to a rapid gut transit time, but some seeds can remain in the gut for more than twelve hours. This heightens megabats' capacity to disperse seeds far from parent trees.<ref>{{cite journal|doi=10.1098/rspb.1999.0625|pmc=1689670|title=Old World fruit bats can be long-distance seed dispersers through extended retention of viable seeds in the gut|journal=[[Proceedings of the Royal Society of London. Series B: Biological Sciences]]|volume=266|issue=1416|pages=219–223|year=1999|last1=Shilton|first1=L. A.|last2=Altringham|first2=J. D.|last3=Compton|first3=S. G.|last4=Whittaker|first4=R. J.}}</ref> As highly mobile frugivores, megabats have the capacity to restore forest between isolated forest fragments by dispersing tree seeds to deforested landscapes.<ref>{{cite journal|doi=10.1016/j.gecco.2015.02.012|title=High-resolution GPS tracking reveals habitat selection and the potential for long-distance seed dispersal by Madagascan flying foxes Pteropus rufus|journal=Global Ecology and Conservation|volume=3|page=690|year=2015|last1=Oleksy|first1=R. |last2=Racey|first2=P. A.|last3=Jones|first3=G.|doi-access=free|bibcode=2015GEcoC...3..678O }}</ref> This dispersal ability is limited to plants with small seeds that are less than {{cvt|4|mm|in}} in length, as seeds larger than this are not ingested.<ref>{{cite journal|doi=10.1016/j.gecco.2017.04.007|title=Frugivory and seed dispersal by vertebrates in tropical and subtropical Asia: An update|journal=Global Ecology and Conservation|volume=11|page=13|year=2017|last1=Corlett|first1=R. T.|doi-access=free|bibcode=2017GEcoC..11....1C }}</ref>

===Predators and parasites===
[[File:Hardwicke's science-gossip - an illustrated medium of interchange and gossip for students and lovers of nature (1886) (14769069502).jpg|thumb|alt=A drawing of a small insect with spider-like legs|An example of a [[Nycteribiidae|bat fly]], a flightless [[Diptera|fly]] that parasitizes bats, including megabats]]
Megabats, especially those living on islands, have few native predators. Non-native predators of flying foxes include domestic [[cat]]s and [[rat]]s. The [[mangrove monitor]], which is a native predator for some megabat species but an introduced predator for others, opportunistically preys on megabats, as it is a capable tree climber.<ref name="Buden-2013">{{cite journal|doi=10.3897/zookeys.345.5840|pmid=24194666|pmc=3817444|title=Taxonomy, distribution, and natural history of flying foxes (Chiroptera, Pteropodidae) in the Mortlock Islands and Chuuk State, Caroline Islands|journal=[[ZooKeys]]|issue=345|year=2013|last1=Buden|first1=D. |last2=Helgen|first2=K. M.|last3=Wiles|first3=G.|pages=97–135|doi-access=free|bibcode=2013ZooK..345...97B }}</ref> Another species, the [[brown tree snake]], can seriously impact megabat populations; as a non-native predator in [[Guam]], the snake consumes so many offspring that it reduced the [[recruitment (biology)|recruitment]] of the population of the [[Mariana fruit bat]] (''Pteropus mariannus'') to essentially zero. The island is now considered a [[Source–sink dynamics|sink]] for the Mariana fruit bat, as its population there relies on bats immigrating from the nearby island of [[Rota (island)|Rota]] to bolster it rather than successful reproduction.<ref name="Esselstyn 2006">{{cite journal|doi=10.1353/psc.2006.0027|title=Impact of Posttyphoon Hunting on Mariana Fruit Bats (Pteropus mariannus)|journal=[[Pacific Science]]|volume=60|issue=4|pages=531–532|year=2006|last1=Esselstyn|first1=J. A. |last2=Amar|first2=A. |last3=Janeke|first3=D. |bibcode=2006PacSc..60..531E |s2cid=55543225}}</ref> Predators that are naturally [[sympatric]] with megabats include reptiles such as [[crocodilian]]s, snakes, and large lizards, as well as birds like [[falcon]]s, [[hawk]]s, and [[owl]]s.<ref name="Mickleburgh"/>{{rp|5}} The [[saltwater crocodile]] is a known predator of megabats, based on analysis of crocodile stomach contents in northern Australia.<ref>{{cite journal|doi=10.1371/journal.pone.0197159|pmid=29874276|pmc=5991389|title=Estuarine crocodiles in a tropical coastal floodplain obtain nutrition from terrestrial prey|journal=PLOS ONE|volume=13|issue=6|article-number=e0197159|year=2018|last1=Adame|first1=Maria Fernanda|last2=Jardine|first2=T. D.|last3=Fry|first3=B. |last4=Valdez|first4=D. |last5=Lindner|first5=G. |last6=Nadji|first6=J. |last7=Bunn|first7=S. E.|bibcode=2018PLoSO..1397159A|doi-access=free}}</ref> During extreme heat events, megabats like the [[little red flying fox]] (''Pteropus scapulatus'') must cool off and rehydrate by drinking from waterways, making them susceptible to opportunistic depredation by [[freshwater crocodiles]].<ref>{{cite AV media| url=https://www.youtube.com/watch?v=wi30w-Mk2yQ| archive-url=https://ghostarchive.org/varchive/youtube/20211107/wi30w-Mk2yQ| archive-date=2021-11-07 | url-status=live| date=10 April 2015|medium=video| publisher=BBC Earth|title=Flying Foxes Vs Freshwater Crocodile|access-date=22 May 2019}}{{cbignore}}</ref>

Megabats are the hosts of several [[parasite]] taxa. Known parasites include [[Nycteribiidae]] and [[Streblidae]] species ("bat flies"),<ref>{{cite journal|doi=10.1186/s13071-017-2582-x|pmid=29284533|pmc=5747079|title=Hidden diversity of Nycteribiidae (Diptera) bat flies from the Malagasy region and insights on host-parasite interactions|journal=[[Parasites & Vectors]]|volume=10| issue=1|page=630| year=2017|last1=Ramasindrazana| first1=B. |last2=Goodman|first2=S. M.|last3=Gomard|first3=Y. |last4=Dick|first4=C. W.|last5=Tortosa|first5=P. |doi-access=free }}</ref><ref>{{cite journal|doi=10.1186/s13071-018-2918-1|pmid=29859123|pmc=5984742|title=Rates of hematophagous ectoparasite consumption during grooming by an endemic Madagascar fruit bat|journal=Parasites & Vectors|volume=11|issue=1|page=330|year=2018|last1=Ramanantsalama|first1=R. V.|last2=Andrianarimisa|first2=A.|last3=Raselimanana|first3=A. P.|last4=Goodman|first4=S. M. |doi-access=free }}</ref> as well as [[Acari|mites]] of the genus ''[[Demodex]]''.<ref>{{cite journal|last1=Desch| first1= C. E.| year=1981| title= A new species of demodicid mite (Acari: Prostigmata) from Western Australia parasitic on Macroglossus minimus (Chiroptera: Pteropodidae)| journal= [[Records of the Western Australian Museum]]| volume= 9| issue=1| pages= 41–47| url=http://museum.wa.gov.au/sites/default/files/A%20NEW%20SPECIES%20OF%20DEMODICID%20MITE%20(ACARI%20PROSTIGMATA)%20FROM%20WESTERN%20AUSTRALIA%20PARASITIC%20ON%20MACROGLOSSUS%20MINIMUS%20(CHIROPTERA%20PT.pdf}}</ref> Blood parasites of the family [[Haemoproteidae]] and intestinal nematodes of [[Toxocaridae]] also affect megabat species.<ref name="Nelson"/><ref>{{cite journal|doi=10.1051/parasite/2012192137|doi-access=free|pmid=22550624|pmc=3671437|title=The haemosporidian parasites of bats with description of ''Sprattiella'' alectogen. Nov., sp. Nov|journal=Parasite|volume=19|issue=2|pages=137–146|year=2012|last1=Landau|first1=I.|last2=Chavatte|first2=J. M.|last3=Karadjian |first3=G.|last4=Chabaud|first4=A.|last5=Beveridge|first5=I.}}</ref>

==Range and habitat==
[[File:Grey-headed flying foxes (Pteropus poliocephalus).webm|upright=1.3|thumb|alt=At dusk, cars drive along a road and a siren is heard in the background. Hundreds of silhouettes of flying foxes are visible as they fly over the road.| Grey-headed flying foxes (''Pteropus poliocephalus'') fly through the suburbs of [[Sydney|Sydney, Australia]].]]
Megabats are widely distributed in the [[tropics]] of the [[Old World]], occurring throughout Africa, Asia, Australia, and throughout the islands of the Indian Ocean and [[Oceania]].<ref name="Almeida 2011"/> As of 2013, fourteen genera of megabat are present in Africa, representing twenty-eight species. Of those twenty-eight species, twenty-four are only found in tropical or [[subtropical]] climates. The remaining four species are mostly found in the tropics, but their ranges also encompass [[temperate climate]]s. In respect to habitat types, eight are exclusively or mostly found in [[forest]]ed habitat; nine are found in both forests and [[savanna]]s; nine are found exclusively or mostly in savannas; and two are found on islands. Only one African species, the [[long-haired rousette]] (''Rousettus lanosus''), is found mostly in [[montane ecosystem]]s, but an additional thirteen species' ranges extend into montane habitat.<ref name="Kingdon 2013">{{cite book| last1=Kingdon| first1= J.| last2= Happold| first2= D.| last3= Butynski| first3= T.| last4= Hoffmann| first4= M.| last5= Happold| first5= M.| last6= Kalina| first6= J.| date= 2013| title= Mammals of Africa| volume=4| publisher= A&C Black|isbn=978-1-4081-8996-2|url=https://www.researchgate.net/publication/250612228}}</ref>{{rp|226}}

Outside of Southeast Asia, megabats have relatively low species richness in Asia. The Egyptian fruit bat is the only megabat whose range is mostly in the [[Palearctic realm]];<ref name="Benda 2012">{{cite journal|doi=10.2478/s11756-012-0105-y|title=The Egyptian fruit bat Rousettus aegyptiacus (Chiroptera: Pteropodidae) in the Palaearctic: Geographical variation and taxonomic status|journal=Biologia|volume=67|issue=6|year=2012|last1=Benda|first1=Petr|last2=Vallo|first2=Peter|last3=Hulva|first3=Pavel|last4=Horáček|first4=Ivan|pages=1230–1244|bibcode=2012Biolg..67.1230B |s2cid=14907114|url=https://digitalcommons.usf.edu/cgi/viewcontent.cgi?article=2495&context=kip_articles|url-access=subscription}}</ref> it and the straw-colored fruit bat are the only species found in the [[Middle East]].<ref name="Benda 2012"/><ref>{{cite iucn|last1=Mickleburgh| first1= S.| last2= Hutson| first2= A.M.| last3= Bergmans| first3= W.| last4= Fahr| first4= J.| last5= Racey| first5= P.A.| year= 2008| title= Eidolon helvum|volume= 2008| article-number= e.T7084A12824968| doi= 10.2305/IUCN.UK.2008.RLTS.T7084A12824968.en}}</ref> The northernmost extent of the Egyptian fruit bat's range is the northeastern [[Mediterranean Sea|Mediterranean]].<ref name="Benda 2012"/> In [[East Asia]], megabats are found only in China and Japan. In China, only six species of megabat are considered resident, while another seven are present marginally (at the edge of their ranges), questionably (due to possible misidentification), or as accidental migrants.<ref>{{cite journal|doi=10.3161/150811010X504626|title=Recent Surveys of Bats (Mammalia: Chiroptera) from China II. Pteropodidae|journal=Acta Chiropterologica|volume=12|pages=103–116|year=2010|last1=Zhang|first1=Jin-Shuo|last2=Jones|first2=Gareth|last3=Zhang|first3=Li-Biao|last4=Zhu|first4=Guang-Jian|last5=Zhang|first5=Shu-Yi|s2cid=86402486}}</ref> Four megabat species, all ''Pteropus'', are found on Japan, but none on its five main islands.<ref>{{cite iucn | author = Vincenot, C. | title = ''Pteropus dasymallus'' | volume = 2017 | article-number = e.T18722A22080614 | date = 2017 | doi = 10.2305/IUCN.UK.2017-2.RLTS.T18722A22080614.en }}</ref><ref>{{cite iucn|last1=Maeda| first1= K.| year= 2008| title= Pteropus loochoensis| volume= 2008| article-number= e.T18773A8614831| doi= 10.2305/IUCN.UK.2008.RLTS.T18773A8614831.en}}</ref><ref>{{Cite iucn | author = Vincenot, C. | title = ''Pteropus pselaphon'' | volume = 2017 | article-number = e.T18752A22085351 | date = 2017 | doi = 10.2305/IUCN.UK.2017-2.RLTS.T18752A22085351.en }}</ref><ref name="Allison, A. 2008 e.T18737A8516291">{{Cite iucn | author = Allison, A. | author2 = Bonaccorso, F. | author3 = Helgen, K. | author4 = James, R. | name-list-style = amp | title = ''Pteropus mariannus'' | volume = 2008 | article-number = e.T18737A8516291 | date = 2008 | doi = 10.2305/IUCN.UK.2008.RLTS.T18737A8516291.en }}</ref> In [[South Asia]], megabat species richness ranges from two species in the [[Maldives]] to thirteen species in [[India]].<ref name="S and SE Asia">{{cite web|url=https://www.iucnredlist.org/search?searchType=species|website=IUCN|access-date=24 August 2019| title=<nowiki>Taxonomy=Pteropodidae</nowiki>, <nowiki>Land Regions=West and Central Asia, South and Southeast Asia</nowiki>}}</ref> Megabat species richness in Southeast Asia is as few as five species in the small country of Singapore and seventy-six species in [[Indonesia]].<ref name="S and SE Asia"/> Of the ninety-eight species of megabat found in Asia, forest is a habitat for ninety-five of them.  Other habitat types include human-modified land (66 species), caves (23 species), savanna (7 species), shrubland (4 species), rocky areas (3 species), grassland (2 species), and desert (1 species).<ref name="S and SE Asia"/>

In Australia, five genera and eight species of megabat are present. These genera are ''Pteropus'', ''Syconycteris'', ''Dobsonia'', ''Nyctimene'', and ''Macroglossus''.<ref name="Nelson"/>{{rp|3}} ''Pteropus'' species of Australia are found in a variety of habitats, including [[mangrove]]-dominated forests, [[rainforest]]s, and the [[Sclerophyll#Australian bush|wet sclerophyll forests]] of the Australian bush.<ref name="Nelson"/>{{rp|7}} Australian ''Pteropus'' are often found in association with humans, as they situate their large colonies in [[urbanization|urban areas]], particularly in May and June when the greatest proportions of ''Pteropus'' species populations are found in these urban colonies.<ref>{{cite journal|doi=10.1371/journal.pone.0109810|pmid=25295724|pmc=4190360|title=Are Flying-Foxes Coming to Town? Urbanisation of the Spectacled Flying-Fox (Pteropus conspicillatus) in Australia|journal=PLOS ONE|volume=9|issue=10|article-number=e109810|year=2014|last1=Tait|first1=Jessica|last2=Perotto-Baldivieso|first2=Humberto L.|last3=McKeown|first3=Adam|last4=Westcott|first4=David A.|bibcode=2014PLoSO...9j9810T|doi-access=free}}</ref>

In Oceania, the countries of [[Palau]] and [[Tonga]] have the fewest megabat species, with one each. [[Papua New Guinea]] has the greatest number of species with thirty-six.<ref name="Oceania">{{cite web|url=https://www.iucnredlist.org/search?searchType=species|website=IUCN|access-date=24 August 2019| title=<nowiki>Taxonomy=Pteropodidae</nowiki>, <nowiki>Land Regions=Oceania</nowiki>}}</ref> Of the sixty-five species of Oceania, forest is a habitat for fifty-eight. Other habitat types include human-modified land (42 species), caves (9 species), savanna (5 species), shrubland (3 species), and rocky areas (3 species).<ref name="Oceania"/> An estimated nineteen percent of all megabat species are [[endemism|endemic]] to a single island; of all bat families, only [[Myzopodidae]]—containing two species, both single-island endemics—has a higher rate of single-island endemism.<ref>{{cite book| title=Evolution ecology and conservation of Island bats| chapter=Global overview of the conservation of island bats: importance challenges and opportunities| last1=Jones| first1=K. E.| last2=Mickleburgh| first2=S. P.| last3=Sechrest| first3=W.| last4=Walsh| first4=A. L.| editor1-last=Fleming| editor1-first=T. H.| editor2-last=Racey| editor2-first=P. A.| chapter-url=https://www.researchgate.net/publication/272508686| publisher=University of Chicago Press}}</ref>

==Relationship to humans==
===Food===
{{Main|Bat as food|Pteropus#Food}}

Megabats are killed and eaten as [[bushmeat]] throughout their range. Bats are consumed extensively throughout Asia, as well as in islands of the West Indian Ocean and the Pacific, where ''Pteropus'' species are heavily hunted. In continental Africa where no ''Pteropus'' species live, the straw-colored fruit bat, the region's largest megabat, is a preferred hunting target.<ref>{{cite journal|doi=10.1017/s0030605308000938|title=Bats as bushmeat: A global review|journal=[[Oryx (journal)|Oryx]]|volume=43|issue=2|page=217|year=2009|last1=Mickleburgh|first1=S.|last2=Waylen|first2=K.|last3=Racey|first3=P.|bibcode=2009Oryx...43..217M |s2cid=85261295|doi-access=free}}</ref>

In Guam, consumption of the Mariana fruit bat exposes locals to the [[neurotoxin]] [[beta-Methylamino-L-alanine]] (BMAA) which may later lead to [[Neurodegeneration|neurodegenerative diseases]]. BMAA may become particularly [[Biomagnification|biomagnified]] in humans who consume flying foxes; flying foxes are exposed to BMAA by eating [[cycad]] fruits.<ref name="Banack 2006">{{cite journal|doi=10.1016/j.jep.2005.12.032|pmid=16457975|title=Neurotoxic flying foxes as dietary items for the Chamorro people, Marianas Islands|journal=[[Journal of Ethnopharmacology]]|volume=106|issue=1|pages=97–104|year=2006|last1=Banack|first1=S. A. |last2=Murch|first2=S. J.|last3=Cox|first3=P. A. |bibcode=2006JEthn.106...97B }}</ref><ref name="Cox 2016" >{{cite journal | last1 = Cox| first1= P.| last2= Davis| first2= D.| last3= Mash| first3= D.| last4= Metcalf| first4= J. S.| last5= Banack| first5= S. A. | year = 2016 | title = Dietary exposure to an environmental toxin triggers neurofibrillary tangles and amyloid deposits in the brain |journal= Proceedings of the Royal Society B |volume =  283| issue = 3 | doi = 10.1098/rspb.2015.2397|  pages=1–10 | pmid=26791617 | pmc=4795023| bibcode= 2016PBioS.28352397C}}</ref><ref name=Holtcamp>{{cite journal | last1 = Holtcamp| first1= W. | year = 2012 | title = The emerging science of BMAA: do cyanobacteria contribute to neurodegenerative disease? | journal = [[Environmental Health Perspectives]] | volume = 120| issue = 1823 | doi = 10.1289/ehp.120-a110 | pmid=22382274 | pmc=3295368 | pages=a110–a116}}</ref>

=== As disease reservoirs ===
[[File:Egyptian fruit bat.jpg|thumb|alt=A yellowish-gray megabat sits atop a skewer of fruit slices, including banana and apple.|The [[Egyptian fruit bat]] (''Rousettus aegyptiacus''), which has tested positive for [[Marburg virus]] and antibodies against the [[Ebola virus]], though not the actual virus]]
[[File:Hendra-distribution-map.jpg|upright=1.3|thumb|alt=A map of Madagascar, Asia, and Oceania. Madagascar, Southern and Southeast Asia, and most of Oceania is delimited as flying fox distribution. The northeast coast of Australia shows small red icons that indicate Hendra virus outbreaks. South and Southeast Asia has several blue icons that indicate Nipah virus outbreaks.|[[Henipavirus]] outbreaks overlaid on flying fox distribution map, with [[Nipah virus]] as blue icons and [[Hendra virus]] as red icons]]
Megabats are the [[natural reservoir|reservoirs]] of several [[virus]]es that can affect humans and cause disease. They can carry [[filovirus]]es, including the [[Ebola virus]] (EBOV) and ''[[Marburgvirus]]''.<ref name="Hassanin" /> The presence of ''Marburgvirus'', which causes [[Marburg virus disease]], has been confirmed in one species, the Egyptian fruit bat. The disease is rare, but the fatality rate of an outbreak can reach up to 88%.<ref name="Hassanin"/><ref name="who" /> The virus was first recognized after simultaneous outbreaks in the German cities of [[Marburg]] and [[Frankfurt]] as well as [[Belgrade|Belgrade, Serbia]], in 1967,<ref name="who">{{cite web|url=https://www.afro.who.int/health-topics/marburg-haemorrhagic-fever| title=Marburg Haemorrhagic Fever| website=World Health Organization| access-date=30 May 2019}}</ref> where 31 people became ill and seven died.<ref name="cdc" /> The outbreak was traced to [[laboratory]] work with [[vervet monkey]]s from [[Uganda]].<ref name="who"/> The virus can pass from a bat host to a human (who has usually spent a prolonged period in a mine or cave where Egyptian fruit bats live); from there, it can spread person-to-person through contact with infected bodily fluids, including blood and [[semen]].<ref name="who" /> The United States [[Centers for Disease Control and Prevention]] lists a total of 601 confirmed cases of Marburg virus disease from 1967 to 2014, of which 373 people died (62% overall mortality).<ref name="cdc">{{cite web|url=https://www.cdc.gov/vhf/marburg/resources/outbreak-table.html| title=Chronology of Marburg Hemorrhagic Fever Outbreaks| website=Centers for Disease Control and Prevention|date=9 October 2014|access-date=30 May 2019}}</ref>

Species that have tested positive for the presence of EBOV include [[Franquet's epauletted fruit bat]] (''Epomops franqueti''), the hammer-headed fruit bat, and the little collared fruit bat. Additionally, [[antibody|antibodies]] against EBOV have been found in the straw-colored fruit bat, [[Gambian epauletted fruit bat]] (''Epomophorus gambianus''), [[Peters's dwarf epauletted fruit bat]] (''Micropteropus pusillus''), [[Veldkamp's dwarf epauletted fruit bat]] (''Nanonycteris veldkampii''), Leschenault's rousette, and the Egyptian fruit bat.<ref name="Hassanin">{{cite journal|doi=10.1016/j.crvi.2016.09.005|pmid=27746072|title=Comparative phylogeography of African fruit bats (Chiroptera, Pteropodidae) provide new insights into the outbreak of Ebola virus disease in West Africa, 2014–2016|journal=[[Comptes Rendus Biologies]]|volume=339|issue=11–12|pages=517–528|year=2016|last1=Hassanin|first1=A. |last2=Nesi|first2=N. |last3=Marin|first3=J. |last4=Kadjo|first4=B. |last5=Pourrut|first5=X. |last6=Leroy|first6=É. |last7=Gembu|first7=G. |last8=Musaba Akawa|first8=P. |last9=Ngoagouni|first9=C. |last10=Nakouné|first10=E. |last11=Ruedi|first11=M. |last12=Tshikung|first12=D. |last13=Pongombo Shongo|first13=C.|last14=Bonillo|first14=C.|s2cid=44412099 |url=https://hal.sorbonne-universite.fr/hal-01382796/document|doi-access=free}}</ref> Much of how humans contract the Ebola virus is unknown. Scientists hypothesize that humans initially become infected through contact with an infected animal such as a megabat or non-human primate.<ref>{{cite web|url=https://www.cdc.gov/vhf/ebola/transmission/index.html| title=Ebola (Ebola Virus Disease): Transmission| access-date=30 May 2019|date=17 May 2019| website=Centers for Disease Control and Prevention}}</ref> Megabats are presumed to be a natural reservoir of the Ebola virus, but this has not been firmly established.<ref>{{cite web|url=https://www.cdc.gov/ncezid/stories-features/global-stories/ebola-reservoir-study.html| title=Ebola Reservoir Study| website=Centers for Disease Control and Prevention|access-date=30 May 2019|date=9 July 2018}}</ref> Microbats are also being investigated as the reservoir of the virus, with the [[greater long-fingered bat]] (''Miniopterus inflatus'') once found to harbor a fifth of the virus's genome (though not testing positive for the actual virus) in 2019.<ref>{{cite web|url=https://www.science.org/content/article/bat-species-may-be-source-ebola-epidemic-killed-more-11000-people-west-africa| title=This bat species may be the source of the Ebola epidemic that killed more than 11,000 people in West Africa| first=K.| last= Kupferschmidt|date=24 January 2019| access-date=30 May 2019| website=Science}}</ref> Due to the likely association between Ebola infection and "hunting, butchering and processing meat from infected animals", several West African countries banned bushmeat (including megabats) or issued warnings about it during the [[Western African Ebola virus epidemic|2013–2016 epidemic]]; many bans have since been lifted.<ref>{{cite web| url=https://www.apnews.com/2ff0034f651a4e229c6d9a74b21bc80f| title=Post-Ebola, West Africans flock back to bushmeat, with risk| website=Associated Press| first1=H.| last1=Zon| first2=C.| last2=Petesch| date=21 September 2016| access-date=30 May 2019| archive-date=25 December 2019| archive-url=https://web.archive.org/web/20191225100557/https://apnews.com/2ff0034f651a4e229c6d9a74b21bc80f}}</ref>

Other megabats implicated as disease reservoirs are primarily ''Pteropus'' species. Notably, flying foxes can transmit [[Australian bat lyssavirus]], which, along with the [[rabies virus]], causes [[rabies]]. Australian bat lyssavirus was first identified in 1996; it is very rarely transmitted to humans. Transmission occurs from the bite or scratch of an infected animal but can also occur from getting the infected animal's saliva in a [[mucous membrane]] or an open [[wound]]. Exposure to flying fox blood, urine, or feces cannot cause infections of Australian bat lyssavirus. Since 1994, there have been three records of people becoming infected with it in [[Queensland]]—each case was fatal.<ref name="NSW">{{cite web| url=http://www.health.nsw.gov.au/Infectious/factsheets/Pages/rabies-australian-bat-lyssavirus-infection.aspx| title=Rabies and Australian bat lyssavirus infection fact sheet| date=30 November 2015| website=health.nsw.gov.au| publisher=State of New South Wales NSW Ministry of Health 2015| access-date=14 June 2018}}</ref>

Flying foxes are also reservoirs of [[henipavirus]]es such as [[Hendra virus]] and [[Nipah virus]]. Hendra virus was first identified in 1994; it rarely occurs in humans. From 1994 to 2013, there have been seven reported cases of Hendra virus affecting people, four of which were fatal. The hypothesized primary route of human infection is via contact with [[horse]]s that have come into contact with flying fox [[Urination|urine]].<ref name="CDC">{{cite web| url=https://www.cdc.gov/vhf/hendra/pdf/factsheet.pdf| title=Hendra Virus Disease(HeV)| website=cdc.gov| publisher=U.S. Department of Health & Human Services| access-date=14 June 2018}}</ref> There are no documented instances of direct transmission between flying foxes and humans.<ref name="Sanchez 2016">{{cite journal|doi=10.1371/journal.pntd.0004411|pmid=26829399|title=Disease Risk Perception and Safety Practices: A Survey of Australian Flying Fox Rehabilitators|journal=PLOS Neglected Tropical Diseases|volume=10|issue=2|article-number=e0004411|year=2016|last1=Sánchez|first1=C. A. |last2=Baker|first2=M. L.|pmc=4734781 |doi-access=free }}</ref> As of 2012, there is a [[vaccine]] available for horses to decrease the likelihood of infection and transmission.<ref name="AVA">{{cite web| url=http://www.ava.com.au/hendra-virus-vaccine| title=The Hendra vaccine| website=ava.com| publisher=The Australian Veterinary Association Ltd (AVA)| date=2018| access-date=14 June 2018| archive-date=14 June 2018| archive-url=https://web.archive.org/web/20180614194613/http://www.ava.com.au/hendra-virus-vaccine}}</ref>

Nipah virus was first identified in 1998 in Malaysia. Since 1998, there have been several Nipah outbreaks in Malaysia, [[Singapore]], India, and Bangladesh, resulting in over 100 casualties. A [[2018 Nipah virus outbreak in Kerala|2018 outbreak]] in [[Kerala|Kerala, India]], resulted in 19 humans becoming infected—17 died.<ref name="Gulland 2018">{{cite web| url=https://www.telegraph.co.uk/news/2018/06/12/nipah-virus-control-india-britain-world-must-alert-signs-infected/ |archive-url=https://ghostarchive.org/archive/20220112/https://www.telegraph.co.uk/news/2018/06/12/nipah-virus-control-india-britain-world-must-alert-signs-infected/ |archive-date=12 January 2022 |url-access=subscription |url-status=live| title=Nipah virus 'under control' in India – but Britain and the world must be alert for signs of infected travellers| last=Gulland| first=A.| date=12 June 2018| website=The Telegraph| publisher=Telegraph Media Group Limited 2018| access-date=14 June 2018}}{{cbignore}}</ref> The overall fatality rate is 40–75%. Humans can contract Nipah virus from direct contact with flying foxes or their fluids, through exposure to an intermediate [[host (biology)|host]] such as [[domestic pig]]s, or from contact with an infected person.<ref name="WHO">{{cite web| url=https://www.who.int/news-room/fact-sheets/detail/nipah-virus| title=Nipah virus| website=World Health Organization| publisher=WHO| date=30 May 2018| access-date=14 June 2018}}</ref> A 2014 study of the Indian flying fox and Nipah virus found that while Nipah virus outbreaks are more likely in areas preferred by flying foxes, "the presence of bats in and of itself is not considered a risk factor for Nipah virus infection." Rather, the consumption of [[date palm#Sap|date palm sap]] is a significant route of transmission. The practice of date palm sap collection involves placing collecting pots at date palm trees. Indian flying foxes have been observed licking the sap as it flows into the pots, as well as defecating and urinating in proximity to the pots. In this way, humans who drink palm wine can be exposed to henipaviruses. The use of bamboo skirts on collecting pots lowers the risk of contamination from bat urine.<ref name="Hahn 2014">{{cite journal| last1=Hahn| first1= M. B.| last2=Epstein |first2= J. H.| last3= Gurley| first3= E. S.| last4= Islam| first4= M. S.| last5= Luby| first5= S. P.| last6= Daszak| first6= P.| last7=Patz| first7= J. A.| date=2014| title= Roosting behaviour and habitat selection of Pteropus giganteus reveal potential links to Nipah virus epidemiology| journal=[[Journal of Applied Ecology]]| volume= 51| issue=2| pages=376–387| doi=10.1111/1365-2664.12212| pmid= 24778457| pmc=4000083| bibcode= 2014JApEc..51..376H}}</ref>

Flying foxes can transmit several non-lethal diseases as well, such as [[Menangle virus]]<ref name="Bowden 2001">{{cite journal|doi=10.1006/viro.2001.0893|pmid=11336561|title=Molecular Characterization of Menangle Virus, a Novel Paramyxovirus which Infects Pigs, Fruit Bats, and Humans|journal=[[Virology (journal)|Virology]]|volume=283|issue=2|pages=358–73|year=2001|last1=Bowden|first1=T. R. |last2=Westenberg|first2=M.|last3=Wang|first3=L.|last4=Eaton|first4=B. T.|last5=Boyle|first5=D. B.|doi-access=free}}</ref> and [[Nelson Bay virus]].<ref name="Yamanaka 2014">{{cite journal|doi=10.1371/journal.pone.0092777|pmid=24667794|title=Imported Case of Acute Respiratory Tract Infection Associated with a Member of Species Nelson Bay Orthoreovirus|journal=PLOS ONE|volume=9|issue=3 |article-number=e92777|year=2014 |last1=Yamanaka|first1=A. |last2=Iwakiri|first2=A. |last3=Yoshikawa|first3=T. |last4=Sakai|first4=K. |last5=Singh|first5=H. |last6=Himeji|first6=D. |last7=Kikuchi|first7=I. |last8=Ueda|first8=A. |last9=Yamamoto|first9=S. |last10=Miura|first10=M. |last11=Shioyama|first11=Y. |last12=Kawano|first12=K. |last13=Nagaishi|first13=T. |last14=Saito|first14=M. |last15=Minomo|first15=M. |last16=Iwamoto|first16=N. |last17=Hidaka|first17=Y. |last18=Sohma|first18=H. |last19=Kobayashi|first19=T. |last20=Kanai|first20=Y. |last21=Kawagishi|first21=T. |last22=Nagata|first22=N. |last23=Fukushi|first23=S. |last24=Mizutani|first24=T. |last25=Tani|first25=H. |last26=Taniguchi|first26=S. |last27=Fukuma|first27=A. |last28=Shimojima|first28=M. |last29=Kurane|first29=I. |last30=Kageyama|first30=T.|display-authors=29|bibcode=2014PLoSO...992777Y|pmc=3965453|doi-access=free}}</ref> These viruses rarely affect humans, and few cases have been reported.<ref name="Bowden 2001" /><ref name="Yamanaka 2014" /> Megabats are not suspected to be vectors of [[coronaviruses]].<ref name="Smith 2013">{{Cite journal|doi=10.1016/j.coviro.2012.11.006|pmid=23265969 | title=Bats and their virome: An important source of emerging viruses capable of infecting humans|journal=[[Current Opinion in Virology]] | volume=3 | issue=1 | pages=84–91 | year=2013 | last1=Smith | first1=I. | last2=Wang | first2=L.|pmc=7102720 |bibcode=2013COVir...3...84S }}</ref>

===In culture===
[[File:Red infill flying fox - Google Art Project.jpg|thumb|right|upright=0.9|A flying fox depicted in [[indigenous Australian art]]]]
Megabats, particularly flying foxes, are featured in indigenous cultures and traditions. Folk stories from Australia and Papua New Guinea feature them.<ref name="Campbell 2013">{{cite book| last1= Campbell-McLeod| first1=P.|chapter=Nallawilli-Sit Down (and Listen): The Dreamtime Stories – An Oral Tradition| editor-last=MacDonald| editor-first=M. R.| year= 2013| title=Traditional Storytelling Today: An International Sourcebook| pages=158–159| publisher=Routledge| isbn=978-1-135-91714-2}}</ref><ref name="Slone 2001">{{cite book| editor-last=Slone| editor-first= T. H.| year= 2001| title= One Thousand One Papua New Guinean Nights: Tales from 1972–1985| volume=1| publisher= Masalai Press| isbn=978-0-9714127-1-2}}</ref>
They were also included in Indigenous Australian cave art, as evinced by several surviving examples.<ref name="Parish 2012">{{cite book| last1=Parish| first1= S.| last2= Richards| first2= G.| last3= Hall| first3= L.| year=2012| title= A natural history of Australian Bats: working the night shift| publisher= Csiro Publishing| isbn=978-0-643-10376-4}}</ref>

Indigenous societies in Oceania used parts of flying foxes for functional and ceremonial weapons. In the Solomon Islands, people created barbs out of their bones for use in spears.<ref name="BM 1910"/> In New Caledonia, [[Ceremonial weapon|ceremonial axes]] made of [[jade]] were decorated with braids of flying fox fur.<ref name="Machray 1899">{{cite journal| last=Machray| first=Robert| year=1899| title=Strange Kinds of Money| journal=The Harmsworth Monthly Pictorial Magazine| volume=1|pages=639–641| url=https://books.google.com/books?id=HvIRAAAAYAAJ&q=flying+fox+fur+cord&pg=PA640}}</ref> Flying fox wings were depicted on the war shields of the [[Asmat people]] of Indonesia; they believed that the wings offered protection to their warriors.<ref name="Werness 2003">{{cite book| last1=Werness| last2= H. B.| year=2003| title= Continuum Encyclopedia of Native Art: Worldview, Symbolism, and Culture in Africa, Oceania, and North America| publisher= A&C Black| page=31|isbn=978-0-8264-1465-6}}</ref>

There are modern and historical references to flying fox byproducts used as [[currency]]. In New Caledonia, braided flying fox fur was once used as currency.<ref name="BM 1910">{{cite book| last1= British Museum. Dept. of British and Mediaeval Antiquities and Ethnography| last2= Joyce| first2= T. A.| last3=Dalton| first3= O. M.| title=Handbook to the Ethnographical Collections| publisher=Printed by order of the Trustees| page=125| url=https://archive.org/stream/handbooktoethnog00brit/handbooktoethnog00brit#page/125/mode/1up| year= 1910}}</ref>
On the island of [[Makira]], which is part of the Solomon Islands, indigenous peoples still hunt flying foxes for their teeth as well as for bushmeat.
The [[Canine tooth|canine teeth]] are strung together on necklaces that are used as currency.<ref name="Choi 2017">{{cite web| last=Choi| first=Charles| date=16 October 2017| title=In Makira, Flying Fox Teeth Are Currency…And That Could Save the Species| website=Discover| publisher=Kalmbach Media| url=http://blogs.discovermagazine.com/d-brief/2017/10/16/flying-fox-currency/#.WxLrZyAh1PY| access-date=2 June 2018| archive-date=12 June 2018| archive-url=https://web.archive.org/web/20180612223317/http://blogs.discovermagazine.com/d-brief/2017/10/16/flying-fox-currency/#.WxLrZyAh1PY}}</ref> Teeth of the [[insular flying fox]] (''Pteropus tonganus'') are particularly prized, as they are usually large enough to drill holes in. The [[Makira flying fox]] (''Pteropus cognatus'') is also hunted, despite its smaller teeth. Deterring people from using flying fox teeth as currency may be detrimental to the species, with Lavery and Fasi noting, "Species that provide an important cultural resource can be highly treasured." Emphasizing [[sustainable hunting]] of flying foxes to preserve cultural currency may be more effective than encouraging the abandonment of cultural currency. Even if flying foxes were no longer hunted for their teeth, they would still be killed for bushmeat; therefore, retaining their cultural value may encourage sustainable hunting practices.<ref name="Lavery 2017">{{cite journal|doi=10.1017/S0030605317001004|title=Buying through your teeth: Traditional currency and conservation of flying foxes Pteropus spp. In Solomon Islands|journal=Oryx|volume=53|issue=3|pages=1–8|year=2017|last1=Lavery|first1=Tyrone H|last2=Fasi|first2=John|s2cid=90302071|doi-access=free}}</ref> Lavery stated, "It's a positive, not a negative, that their teeth are so culturally valuable. The practice of hunting bats shouldn't necessarily be stopped, it needs to be managed sustainably."<ref name="Choi 2017"/>

==Conservation==
===Status===
[[File:Pteropus subniger.png|thumb|upright|alt=A black and white illustration of a flying fox from the back with its face in profile. It has a contrasting mantle of lighter fur on the back of its neck.|The [[small Mauritian flying fox]] (''Pteropus subniger''), which was driven to extinction by overhunting<ref name="Pierson 1992"/>]]
As of 2014, the [[International Union for Conservation of Nature]] (IUCN) evaluated a quarter of all megabat species as [[threatened]], which includes species listed as [[critically endangered]], [[endangered species|endangered]], and [[vulnerable species|vulnerable]]. Megabats are substantially threatened by humans, as they are hunted for food and medicinal uses.
Additionally, they are culled for actual or perceived damage to agriculture, especially to fruit production.<ref name="Aziz 2016">{{cite book| last1=Aziz| first1= S. A.| last2= Olival| first2= K. J.| last3= Bumrungsri| first3= S.| last4= Richards| first4= G. C.| last5= Racey| first5= P. A.| year=2016| chapter= The Conflict Between Pteropodid Bats and Fruit Growers: Species, Legislation and Mitigation| editor1-last= Voigt| editor1-first= C.| editor2-last= Kingston| editor2-first= T.|title= Bats in the Anthropocene: Conservation of Bats in a Changing World| publisher= Springer| isbn=978-3-319-25220-9|doi=10.1007/978-3-319-25220-9_13 | s2cid= 111056244}}</ref> As of 2019, the IUCN had evaluations for 187 megabat species. The status breakdown is as follows:<ref>{{cite web|url=https://www.iucnredlist.org/search/stats| title=<nowiki>Taxonomy=Pteropodidae</nowiki>| website=IUCN Red List of Threatened Species|year=2019| access-date=19 May 2019}}</ref>
* Extinct: 4 species (2.1%)
* Critically endangered: 8 species (4.3%)
* Endangered: 16 species (8.6%)
* Vulnerable: 37 species (19.8%)
* [[Near-threatened species|Near-threatened]]: 13 species (7.0%)
* [[Least-concern species|Least-concern]]: 89 species (47.6%)
* [[Data deficient]]: 20 species (10.7%)

===Factors causing decline===
====Anthropogenic sources====
[[File:Electrocuted flying fox.jpg|thumb|left|alt=A dead flying fox hangs on overhead power lines, with blue sky behind it.|An electrocuted megabat on overhead power lines in Australia]]

Megabats are threatened by habitat destruction by humans. [[Deforestation]] of their habitats has resulted in the loss of critical roosting habitat. Deforestation also results in the loss of food resource, as native fruit-bearing trees are felled. Habitat loss and resulting urbanization leads to construction of new roadways, making megabat colonies easier to access for overharvesting. Additionally, habitat loss via deforestation compounds natural threats, as fragmented forests are more susceptible to damage from [[typhoon]]-force winds.<ref name="Mickleburgh"/>{{rp|7}} Cave-roosting megabats are threatened by human disturbance at their roost sites. [[Guano]] mining is a livelihood in some countries within their range, bringing people to caves. Caves are also disturbed by mineral mining and cave tourism.<ref name="Mickleburgh"/>{{rp|8}}

Megabats are also killed by humans, intentionally and unintentionally. Half of all megabat species are hunted for food, in comparison to only eight percent of insectivorous species,<ref>{{cite book|doi=10.1007/978-3-319-25220-9_12|chapter=Exploitation of Bats for Bushmeat and Medicine|title=Bats in the Anthropocene: Conservation of Bats in a Changing World|page=327|year=2016|last1=Mildenstein|first1=T.|last2=Tanshi|first2=I.|last3=Racey|first3=P. A.|publisher=Springer|isbn=978-3-319-25218-6|s2cid=130038936}}</ref> while human persecution stemming from perceived damage to crops is also a large source of mortality. Some megabats have been documented to have a preference for native fruit trees over fruit crops, but deforestation can reduce their food supply, causing them to rely on fruit crops.<ref name="Mickleburgh"/>{{rp|8}} They are shot, beaten to death, or poisoned to reduce their populations. Mortality also occurs via accidental entanglement in [[bird netting|netting]] used to prevent the bats from eating fruit.<ref name="Vincenot 2015">{{cite journal|doi=10.1016/j.mambio.2015.03.003|title=Near threatened? First report of unsuspected human-driven decline factors in the Ryukyu flying fox (Pteropus dasymallus) in Japan|journal=Mammalian Biology – Zeitschrift für Säugetierkunde|volume=80|issue=4|page=273|year=2015|last1=Vincenot|first1=C. E.|last2=Koyama|first2=L.|last3=Russo|first3=D.|bibcode=2015MamBi..80..273V }}</ref> Culling campaigns can dramatically reduce megabat populations. In Mauritius, over 40,000 Mauritian flying foxes were culled between 2014 and 2016, reducing the species' population by an estimated 45%.<ref name="Vincenot 2017c">{{cite journal|doi=10.1126/science.aam7582 |pmid=28360279 |title=Can we protect island flying foxes? |journal=Science |volume=355 |issue=6332 |pages=1368–1370 |year=2017 |last1=Vincenot |first1=C. E. |last2=Florens |first2=F. B. V. |last3=Kingston |first3=T. |bibcode=2017Sci...355.1368V |s2cid=206657272 }}</ref> Megabats are also killed by electrocution. In one Australian orchard, it is estimated that over 21,000 bats were electrocuted to death in an eight-week period.<ref name="McIlwee 2002">{{cite journal|doi=10.7882/AZ.2002.008|title=On the intrinsic capacity for increase of Australian flying-foxes (Pteropus spp., Megachiroptera)|journal=[[Australian Zoologist]]|volume=32|page=93|year=2002|last1=McIlwee|first1=A. P.|last2=Martin|first2=L.}}</ref> Farmers construct electrified grids over their fruit trees to kill megabats before they can consume their crop. The grids are questionably effective at preventing crop loss, with one farmer who operated such a grid estimating they still lost {{convert|100-120|tonne|lb|lk=in}} of fruit to flying foxes in a year.<ref name="Martin 2011">{{cite book|doi=10.7882/FS.2011.039|chapter=Is the fruit you eat flying-fox friendly? The effects of orchard electrocution grids on Australian flying-foxes (Pteropus spp., Megachiroptera)|title=The Biology and Conservation of Australasian Bats|pages=380–390|year=2011|last1=Martin|first1=L.|isbn=978-0-9803272-4-3|publisher=Royal Zoological Society of New South Wales}}</ref> Some electrocution deaths are also accidental, such as when bats fly into [[overhead power line]]s.<ref name="Chlopicki 2016">{{cite web| url=https://www.dailytelegraph.com.au/newslocal/macarthur/electric-wires-threaten-flying-foxes-and-their-new-babies/news-story/2fc9955551b46a552b04a1eac1043df0| title=Electric wires threaten flying foxes and their new babies| date=28 October 2016| last=Chlopicki| first=K. |website=[[The Daily Telegraph]]| access-date=26 June 2018}}</ref>

Climate change causes flying fox mortality and is a source of concern for species persistence. Extreme heat waves in Australia have been responsible for the [[Australian flying fox die-offs|deaths of more than 30,000 flying foxes]] from 1994 to 2008. Females and young bats are most susceptible to extreme heat, which affects a population's ability to recover.<ref name="Welbergen 2008">{{cite journal|doi=10.1098/rspb.2007.1385|pmid=18048286|pmc=2596826|title=Climate change and the effects of temperature extremes on Australian flying-foxes|journal=Proceedings of the Royal Society B: Biological Sciences|volume=275|issue=1633|pages=419–425|year=2008|last1=Welbergen|first1=J. A. |last2=Klose|first2=S. M.|last3=Markus|first3=N.|last4=Eby|first4=P.}}</ref> Megabats are threatened by sea level rise associated with climate change, as several species are endemic to low-lying [[atoll]]s.<ref name="Buden-2013" />

====Natural sources====
Because many species are endemic to a single island, they are vulnerable to random events such as typhoons. A 1979 typhoon halved the remaining population of the [[Rodrigues flying fox]] (''Pteropus rodricensis''). Typhoons result in indirect mortality as well: because typhoons defoliate the trees, they make megabats more visible and thus more easily hunted by humans. Food resources for the bats become scarce after major storms, and megabats resort to riskier foraging strategies such as consuming fallen fruit off the ground. There, they are more vulnerable to depredation by domestic cats, dogs, and pigs.<ref name="Pierson 1992">{{cite journal|last1=Pierson| first1= E. D.| last2= Rainey| first2= W. E.| year=1992| title= The biology of flying foxes of the genus Pteropus: a review| journal=Biological Report| volume=90| issue=23| url=https://www.researchgate.net/publication/235094381}}</ref> As many megabat species are located in the tectonically active [[Ring of Fire]], they are also threatened by volcanic eruptions. Flying foxes, including the endangered Mariana fruit bat,<ref name="Allison, A. 2008 e.T18737A8516291"/><ref>{{cite report| url=http://www.cnmijointmilitarytrainingeis.com/system/assets/42/original/10_fruit_bats___cnmi.pdf?1367959616| title=Population Assessment of the Mariana Fruit Bat (Pteropus mariannus mariannus) on Anatahan, Sarigan, Guguan, Alamagan, Pagan, Agrihan, Asuncion, and Maug| date=2010| first=Ernest W.| last=Valdez| access-date=24 August 2019| page=2| publisher=USGS| archive-date=23 March 2019| archive-url=https://web.archive.org/web/20190323045810/http://cnmijointmilitarytrainingeis.com/system/assets/42/original/10_fruit_bats___cnmi.pdf?1367959616}}</ref> have been nearly exterminated from the island of [[Anatahan]] following a series of eruptions beginning in 2003.<ref name="Fleming">{{cite book| title=Island Bats: Evolution, Ecology, and Conservation| editor1-first=T. H.| editor1-last= Fleming| editor2-first= P. A.| editor2-last= Racey| year=2010| publisher=[[University of Chicago Press]]| isbn=978-0-226-25331-2|page=415|url=https://books.google.com/books?id=FLIaH43TcrEC&pg=PA405}}</ref>
{{Clear}}

== References ==
{{Reflist|30em|refs=
<ref name="Richards1983">{{cite encyclopedia |last = Richards |first = G. C. |editor-last = Strahan |editor-first = R. |editor-link = Ronald Strahan |encyclopedia = Complete book of Australian mammals. [[National Photographic Index of Australian Wildlife|The national photographic index of Australian wildlife]] |title = Fruit-bats and their relatives |edition = 1 |year = 1983 |publisher = Angus & Robertson |location = London |isbn = 978-0-207-14454-7 |pages = 271–273}}</ref>
}}

== External links ==
* {{Commons category-inline|Pteropodidae}}
* {{Wikispecies-inline|Pteropodidae}}

{{Pteropodidae}}
{{Taxonbar|from1=Q185230|from2=Q14566618}}
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{{DEFAULTSORT:Megabat}}
[[Category:Megabats| ]]
[[Category:Taxa named by John Edward Gray]]
[[Category:Mammal families]]