Editing Megabat (section)

===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=9780801857898|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.|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=9780080540535}}</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=9780801417535|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>