View source for Struthionidae

{{Short description|Family of birds}}
{{Automatic taxobox
| fossil_range = [[Miocene]]-[[Holocene]] {{Fossil range|21|0}}
| image = Avestruz de cuello azul (Struthio camelus australis), cabo de Buena Esparanza, Sudáfrica, 2018-07-23, DD 87.jpg
| image_caption = ''Struthio camelus australis'' at the [[Cape of Good Hope]], [[South Africa]]
| display_parents = 2
| taxon = Struthionidae
| authority = [[Nicholas Aylward Vigors|Vigors]], 1825<ref>{{ cite journal | last=Vigors | first=Nicholas Aylward | author-link=Nicholas Aylward Vigors | year=1825 | title=Observations on the natural affinities that connect the orders and families of birds | journal=Transactions of the Linnean Society of London | volume=14 | issue=3 | pages=395–517 [483] | doi=10.1111/j.1095-8339.1823.tb00098.x | url=https://zenodo.org/record/1669971 }}</ref>
| type_genus = ''[[Struthio]]''
| type_genus_authority = [[Carl Linnaeus|Linnaeus]], 1758
| subdivision_ranks = Genera
| subdivision = * †''[[Pachystruthio]]''
* ''[[Struthio]]''
| synonyms = * †Struthiolithidae <small>Vjalov 1971</small>
| synonyms_ref = <ref>{{cite book |last=Mlíkovský |first=Jiří |date=2002 |title=Cenozoic birds of the world Part 1: Europe |url=https://www.biologicaldiversity.org/campaigns/global_owl_project/descriptions/Fossil_owls/Mlikovski%202002%20Cenozoic%20birds%20of%20the%20world.pdf |location=Praha |publisher=Ninox Press |page=60|isbn=((80-901105-3-8))}}</ref>
}}

'''Struthionidae''' ({{IPAc-en|ˌ|s|t|r|uː|θ|i|ˈ|ɒ|n|ə|d|i:}}; {{etymology|la|strūthiō|ostrich|grc|''εἶδος'' (eîdos)|appearance, resemblance}}) is a family of [[flightless bird]]s, containing the extant [[ostrich]]es and their extinct relatives. The two extant species of ostrich are the [[common ostrich]] and [[Somali ostrich]], both in the genus ''[[Struthio]]'', which also contains several species known from [[Holocene]] fossils such as the [[Asian ostrich]]. The common ostrich is the more widespread of the two living species, and is the [[Largest birds|largest living bird species]]. The extinct genus ''[[Pachystruthio]]'' from the Late Pliocene-Early Pleistocene of Eurasia is [[largest prehistoric animals|one of the largest]] birds ever.<ref>{{cite journal|last1= Zelenkov|first1=N. V.|last2= Lavrov|first2=A. V.|last3= Startsev|first3=D. B.|last4= Vislobokova|first4=I. A.|last5= Lopatin|first5=A. V.|title= A giant early Pleistocene bird from eastern Europe: unexpected component of terrestrial faunas at the time of early Homo arrival|journal=Journal of Vertebrate Paleontology|year= 2019|volume=39|issue=2|article-number= e1605521|doi= 10.1080/02724634.2019.1605521|bibcode=2019JVPal..39E5521Z |s2cid=198384367}}</ref>

The first species of ''Struthio'' appear during the [[Miocene]] epoch, though various [[Paleocene]], [[Eocene]], and [[Oligocene]] fossils may also belong to the family.<ref>Buffetaut, E.; Angst, D. (November 2014). "Stratigraphic distribution of large flightless birds in the Palaeogene of Europe and its palaeobiological and palaeogeographical implications". Earth-Science Reviews. 138: 394–408. doi:10.1016/j.earscirev.2014.07.001.</ref><ref name="Agnolin 2016">Agnolin et al, Unexpected diversity of ratites (Aves, Palaeognathae) in the early Cenozoic of South America: palaeobiogeographical implications Article in Alcheringa An Australasian Journal of Palaeontology · July 2016 DOI: 10.1080/03115518.2016.1184898</ref> Ostriches are classified in the [[ratite]] group of birds, all extant species of which are flightless, including the [[Kiwi (bird)|kiwi]]s, [[emu]]s, and [[rhea (bird)|rheas]]. Traditionally, the order '''Struthioniformes''' contained all the ratites. However, recent genetic analysis has found that the group is not monophyletic, as it is paraphyletic with respect to the [[tinamou]]s, so the ostriches are usually classified as the only members of the order,<ref>Hackett, S.J. ''et al.'' (2008) A Phylogenomic Study of Birds Reveals Their Evolutionary History. ''Science'', 320, 1763.</ref><ref>Yuri, T. (2013) Parsimony and model-based analyses of indels in avian nuclear genes reveal congruent and incongruent phylogenetic signals. ''Biology'', 2:419–44.</ref> though the [[International Union for Conservation of Nature|IUCN]] uses a broader classification and includes all "ratites" and tinamous in Struthioniformes.<ref>{{Cite web|url=https://www.iucnredlist.org/en|title=The IUCN Red List of Threatened Species|website=IUCN Red List of Threatened Species|access-date=2020-04-10}}</ref>

==Evolution==
Struthionidae is a member of the [[Struthioniformes]], a group of [[paleognath]] birds which first appeared during the Early [[Eocene]], and includes a variety of flightless forms which were present across the Northern Hemisphere (Europe, Asia and North America) during the Eocene epoch. The closest relatives of Struthionidae within the Struthioniformes are the [[Ergilornithidae]], known from the late Eocene to early [[Pliocene]] of Asia. It is therefore most likely that Struthionidae originated in Asia.<ref name=":03">{{Cite journal |last1=Mayr |first1=Gerald |last2=Zelenkov |first2=Nikita |date=2021-11-13 |title=Extinct crane-like birds (Eogruidae and Ergilornithidae) from the Cenozoic of Central Asia are indeed ostrich precursors |url=https://academic.oup.com/auk/article/doi/10.1093/ornithology/ukab048/6338403 |journal=Ornithology |language=en |volume=138 |issue=4 |article-number=ukab048 |doi=10.1093/ornithology/ukab048 |issn=0004-8038|doi-access=free }}</ref> The oldest records of Struthionidae, belonging to the genus ''[[Ostrich|Struthio]]'', are from the Early [[Miocene]] of Africa, around 21 million years old. ''Struthio'' dispersed into and became widespread in Eurasia during the late middle-[[Late Miocene]] epoch beginning around 12 million years ago. ''[[Pachystruthio]]'' from the Late Pliocene of Eurasia contains some of the largest bird species ever with some species likely weighing up to {{Convert|450|kg|lb}}.<ref>{{Cite journal |last1=Widrig |first1=Klara |last2=Field |first2=Daniel J. |date=February 2022 |title=The Evolution and Fossil Record of Palaeognathous Birds (Neornithes: Palaeognathae) |journal=Diversity |language=en |volume=14 |issue=2 |page=105 |doi=10.3390/d14020105 |issn=1424-2818|doi-access=free |bibcode=2022Diver..14..105W |url=https://www.repository.cam.ac.uk/bitstreams/e58973e8-911d-450b-9ebc-97544f5ea076/download }}</ref>[[File:Ostrich Ngorongoro 02.jpg|thumb|left|''Struthio camelus massaicus'', female (left) and male (right)]]
While the relationship of the African fossil species is comparatively straightforward, many Asian species of ostriches have been described from fragmentary remains, and their interrelationships and how they relate to the African ostriches are confusing. In [[China]], ostriches are known to have become extinct only around or even after the end of the [[Last glacial period|last ice age]]; images of ostriches have been found there on prehistoric pottery and [[petroglyph]]s.<ref>Doar, B.G. (2007)  [http://www.chinaheritagequarterly.org/articles.php?searchterm=010_genetalia.inc&issue=010 "Genitalia, Totems and Painted Pottery: New Ceramic Discoveries in Gansu and Surrounding Areas"]. ''China Heritage Quarterly''</ref><ref name=janz>{{cite journal | last1 = Janz | first1 = Lisa | display-authors = etal   | year = 2009 | title = Dating North Asian surface assemblages with ostrich eggshell: implications for palaeoecology and extirpation  | journal = Journal of Archaeological Science | volume = 36 | issue = 9| pages = 1982–1989 | doi=10.1016/j.jas.2009.05.012| bibcode = 2009JArSc..36.1982J }}</ref><ref>{{cite journal|author=Andersson, J. G. |title=Essays on the cenozoic of northern China|journal=Memoirs of the Geological Survey of China (Peking), Series A|volume=3 |year=1923|pages=1–152 (53–77)}}</ref>

==Distribution and habitat==
[[File:Somali ostrich.jpg|thumb|A male Somali ostrich in a Kenyan savanna, showing its blueish neck]]
Today ostriches are only found natively in the wild in [[Africa]], where they occur in a range of open arid and semi-arid habitats such as [[savanna]]s and the [[Sahel]], both north and south of the equatorial forest zone.<ref name="Donegan 2002">{{cite web| url=http://animaldiversity.ummz.umich.edu/site/accounts/information/Struthio_camelus.html | title=Struthio camelus | last=Donegan | first=Keenan | year=2002 | work=Animal Diversity Web | publisher=University of Michigan Museum of Zoology}}</ref> The [[Somali ostrich]] occurs in the [[Horn of Africa]], having evolved isolated from the common ostrich by the geographic barrier of the [[East African Rift]]. In some areas, the common ostrich's [[Masai ostrich|Masai subspecies]] occurs alongside the Somali ostrich, but they are kept from interbreeding by behavioral and ecological differences.<ref name=Freitag>{{cite journal |author1=Freitag, Stephanie |author2=Robinson, Terence J.  |name-list-style=amp |year= 1993|title= Phylogeographic patterns in mitochondrial DNA of the Ostrich (''Struthio camelus'')|journal= The Auk|volume= 110|issue= 3|pages= 614–622|url=http://sora.unm.edu/sites/default/files/journals/auk/v110n03/p0614-p0622.pdf |doi= 10.2307/4088425|jstor=4088425  }}</ref> The [[Arabian ostrich]]es in [[Asia Minor]] and [[Arabia]] were hunted to extinction by the middle of the 20th century, and in [[Israel]] attempts to introduce [[North African ostrich]]es to fill their ecological role have failed.<ref>{{cite news |last=Rinat|first=Zafrir |date=25 December 2007 |title=The Bitter Fate of Ostriches in the Wild |url=https://www.haaretz.com/the-bitter-fate-of-ostriches-in-the-wild-1.235868 |newspaper=[[Haaretz]] |location=Tel Aviv|access-date=10 January 2017 }}</ref> Escaped common ostriches in Australia have established [[wiktionary:feral|feral]] populations.<ref>[http://trevorsbirding.com/ostriches-in-australia-and-near-my-home/ Ostriches in Australia – and near my home]. trevorsbirding.com (13 September 2007)</ref>

==Taxonomy==
[[File:Στρουθοκαμήλου στην Bucaramanga της Κολομβίας.jpg|thumb|Ostrich in Bucaramanga, Colombia]]
In 2019, the species ''S. pannonicus'', ''S. dmanisensis'' (the giant ostrich), and ''S. transcaucasicus'' were transferred to the genus ''[[Pachystruthio]]''.<ref name="Zelenkov2019">{{cite journal|last1= Zelenkov|first1=N. V.|last2= Lavrov|first2=A. V.|last3= Startsev|first3=D. B.|last4= Vislobokova|first4=I. A.|last5= Lopatin|first5=A. V.|title= A giant early Pleistocene bird from eastern Europe: unexpected component of terrestrial faunas at the time of early Homo arrival|journal=Journal of Vertebrate Paleontology|volume=39|issue=2|year= 2019|article-number= e1605521|doi= 10.1080/02724634.2019.1605521|bibcode=2019JVPal..39E5521Z |s2cid=198384367 }}</ref>

'''Order Struthioniformes''' <small>Latham 1790</small> (ostriches)
* '''Family Struthionidae''' <small>Vigors 1825</small>
** Genus †''[[Pachystruthio]]'' <small>(Kretzoi 1954)</small> (Late Pliocene {{endash}} Pleistocene)
** Genus ''[[Struthio]]'' <small>Linnaeus 1758</small> (Early Miocene – Recent)

==See also==
*[[Ostrich egg]]

==References==
{{Reflist}}

{{Birds}}
{{Palaeognathae|P.}}
{{Taxonbar|from1=Q1569770|from2=Q840849}}
{{Authority control}}

[[Category:Struthionidae| ]]
[[Category:Extant Paleocene first appearances]]
[[Category:Bird families]]
[[Category:Taxa named by Nicholas Aylward Vigors]]