Editing Elephant bird (section)

== Biology ==
[[File:Aepyornis skull.JPG|thumb|''Aepyornis'' skull]]
Examination of brain [[endocast]]s has shown that both ''A. maximus'' and ''A. hildebrandti'' had greatly reduced [[Superior colliculus|optic lobe]]s, similar to those of their closest living relatives, the kiwis, and consistent with a similar [[nocturnal]] lifestyle. The optic lobes of ''Mullerornis'' were also reduced, but to a lesser degree, suggestive of a nocturnal or [[crepuscular]] lifestyle. ''A. maximus'' had relatively larger [[olfactory bulb]]s than ''A. hildebrandti'', suggesting that the former occupied forested habitats where the sense of smell is more useful while the latter occupied open habitats.<ref name="Torres2018">{{cite journal|last1= Torres|first1=C. R.|last2= Clarke|first2=J. A.|title= Nocturnal giants: evolution of the sensory ecology in elephant birds and other palaeognaths inferred from digital brain reconstructions|journal= Proceedings of the Royal Society B: Biological Sciences|volume= 285|issue= 1890|year= 2018|pages= 20181540|doi= 10.1098/rspb.2018.1540|pmid=30381378|pmc=6235046}}</ref>

=== Diet ===
A 2022 isotope analysis study suggested that some specimens of ''Aepyornis'' ''hildebrandti'' were mixed feeders that had a large (~48%) [[Grazing (behaviour)|grazing]] component to their diets, similar to that of the living ''[[Rhea americana]]'', while the other species (''A. maximus'', ''Mullerornis modestus'') were probably [[Browsing (herbivory)|browsers]].<ref>{{Cite journal |last1=Hansford |first1=James P. |last2=Turvey |first2=Samuel T. |date=April 2022 |title=Dietary isotopes of Madagascar's extinct megafauna reveal Holocene browsing and grazing guilds |journal=Biology Letters |language=en |volume=18 |issue=4 |pages=20220094 |doi=10.1098/rsbl.2022.0094 |issn=1744-957X |pmc=9006009 |pmid=35414222}}</ref> It has been suggested that ''Aepyornis'' straightened its legs and brought its torso into an erect position in order to browse higher vegetation.<ref name=":6" /> Some rainforest fruits with thick, highly sculptured [[endocarp]]s, such as that of the currently undispersed and highly threatened [[forest coconut]] palm (''Voanioala gerardii''), may have been adapted for passage through ratite guts and consumed by elephant birds, and the fruit of some palm species are indeed dark bluish-purple (e.g., ''[[Ravenea louvelii]]'' and ''[[Satranala decussilvae]]''), just like many cassowary-dispersed fruits, suggesting that they too may have been eaten by elephant birds.<ref>Dransfield, J. & Beentje, H. (1995)</ref> 

=== Growth and reproduction ===
Elephant birds are suggested to have grown in periodic spurts rather than having continuous growth.<ref name=":1">{{Cite journal |last1=Chinsamy |first1=Anusuya |last2=Angst |first2=Delphine |last3=Canoville |first3=Aurore |last4=Göhlich |first4=Ursula B |date=2020-06-01 |title=Bone histology yields insights into the biology of the extinct elephant birds (Aepyornithidae) from Madagascar |url=https://academic.oup.com/biolinnean/article/130/2/268/5815707 |journal=Biological Journal of the Linnean Society |language=en |volume=130 |issue=2 |pages=268–295 |doi=10.1093/biolinnean/blaa013 |issn=0024-4066|doi-access=free }}</ref> An embryonic skeleton of ''Aepyornis'' is known from an intact egg, around 80–90% of the way through incubation before it died. This skeleton shows that even at this early ontogenetic stage that the skeleton was robust, much more so than comparable hatchling ostriches or rheas,<ref>{{Cite journal |last1=Balanoff |first1=Amy M. |last2=Rowe |first2=Timothy |date=2007-12-12 |title=Osteological description of an embryonic skeleton of the extinct elephant bird, Aepyornis (Palaeognathae: Ratitae) |url=http://www.tandfonline.com/doi/abs/10.1671/0272-4634%282007%2927%5B1%3AODOAES%5D2.0.CO%3B2 |journal=Journal of Vertebrate Paleontology |language=en |volume=27 |issue=sup4 |pages=1–53 |doi=10.1671/0272-4634(2007)27[1:ODOAES]2.0.CO;2 |s2cid=85920479 |issn=0272-4634|url-access=subscription }}</ref> which may suggest that hatchlings were [[precocial]].<ref name=":1" />

The eggs of ''Aepyornis'' are the largest known for any [[amniote]], and have a volume of around {{Convert|5.6–13|L|USpt}}, a length of approximately {{Convert|26–40|cm|in}} and a width of {{Convert|19–25|cm|in}}.<ref name=":1" /> The largest ''Aepyornis'' eggs are on average {{Convert|3.3|mm|in|abbr=on|frac=64}} thick, with an estimated weight of approximately {{Convert|10.5|kg|lb}}.<ref name="Molecular exploration of fossil eggshell uncovers hidden lineage of giant extinct bird" /> Eggs of ''Mullerornis'' were much smaller, estimated to be only {{Convert|1.1|mm|in|abbr=on|frac=64}} thick, with a weight of about {{Convert|0.86|kg|lb}}.<ref name="Molecular exploration of fossil eggshell uncovers hidden lineage of giant extinct bird" /> The large size of elephant bird eggs means that they would have required substantial amounts of calcium, which is usually taken from a reservoir in the medullary bone in the femurs of female birds. Possible remnants of this tissue have been described from the femurs of ''A. maximus.''<ref name=":1" />{{gallery|Animals of the past (Fig. 16) (5985156816) (cropped).jpg|Eggs of ''Aepyornis'' (top left) chicken (bottom left) [[moa]] (right) and ostrich (centre)|Denis Bourez - Natural History Museum, London (8900355257).jpg|Elephant bird egg (far left, 1) in comparison to other eggs, including ostrich egg (centre, 3) and chicken egg (third from right, 6)|Mus Nat Hist Nat 25022013 Aepyornis egg.jpg|Well preserved egg showing porous surface|Oeuf d'Aepyornis maximus (musée des Douanes).JPG|Egg of ''Aepyornis'' standing upright|||.png||||||width=200|height=180|align=center}}