Emu in the context of Paleognaths

The common ostrich (Struthio camelus), or simply ostrich, is a species of flightless bird native to certain areas of Africa. It is one of two extant species of ostriches, the only living members of the genus Struthio in the ratite group of birds. The other is the Somali ostrich (Struthio molybdophanes), which has been recognized as a distinct species by BirdLife International since 2014, having been previously considered a distinctive subspecies of ostrich.

The common ostrich belongs to the order Struthioniformes. Struthioniformes previously contained all the ratites, such as the kiwis, emus, rheas, and cassowaries. However, recent genetic analysis has found that the group is not monophyletic, as it is paraphyletic with respect to the tinamous, so the ostriches are now classified as the only members of the order. Phylogenetic studies have shown that it is the sister group to all other members of Palaeognathae, and thus the flighted tinamous are the sister group to the extinct moa. It is distinctive in its appearance, with a long neck and legs, and can run for a long time at a speed of 55 km/h (34 mph) with short bursts up to about 70 km/h (43 mph), the fastest land speed of any bipedal animal. The common ostrich is the largest living species of bird and thus the largest living dinosaur. It lays the largest eggs of any living bird (the extinct giant elephant bird (Aepyornis maximus) of Madagascar and the south island giant moa (Dinornis robustus) of New Zealand laid larger eggs).

Flightless birds are birds that cannot fly, as they have, through evolution, lost the ability. There are over 60 extant species, including the well-known ratites (ostriches (Struthio), emus (Dromaius), cassowaries (Casuarius), rheas, and kiwis (Apteryx)) and penguins (Sphenisciformes). The smallest flightless bird is the Inaccessible Island rail (length 12.5 cm, weight 34.7 g). The largest (both heaviest and tallest) flightless bird, which is also the largest living bird in general, is the common ostrich (2.7 m, 156 kg).

Some domesticated birds, such as the domestic chicken, have lost the ability to fly for extended periods, although their ancestral species, the red junglefowl and others, respectively, are capable of extended flight. A few particularly bred birds, such as the Broad Breasted White turkey, have become totally flightless as a result of selective breeding; the birds were bred to grow massive breast meat that weighs too much for the bird's wings to support in flight.

A ranch (from Spanish: rancho/Mexican Spanish) is an area of land, including various structures, given primarily to ranching, the practice of raising grazing livestock such as cattle and sheep. It is a subtype of farm. These terms are most often applied to livestock-raising operations in Mexico, the Western United States and Western Canada, though there are ranches in other areas. People who own or operate a ranch are called ranchers, cattlemen, or stockgrowers. Ranching is also a method used to raise less common livestock such as horses, elk, American bison, ostrich, emu, and alpaca.

Ranches generally consist of large areas, but may be of nearly any size. In the western United States, many ranches are a combination of privately owned land supplemented by grazing leases on land under the control of the federal Bureau of Land Management or the United States Forest Service. If the ranch includes arable or irrigated land, the ranch may also engage in a limited amount of farming, raising crops for feeding the animals, such as hay and feed grains.

Bush tucker, also called bush food, is any food native to Australia and historically eaten by Indigenous Australians and Torres Strait Islander peoples, but it can also describe any native flora, fauna, or fungi used for culinary or medicinal purposes, regardless of the continent or culture. Animal native foods include kangaroo, emu, witchetty grubs and crocodile, and plant foods include fruits such as quandong, kutjera, spices such as lemon myrtle and vegetables such as warrigal greens and various native yams.

Traditional Indigenous Australians' use of bushfoods has been severely affected by the colonisation of Australia beginning in 1788 and subsequent settlement by non-Indigenous peoples. The introduction of non-native organisms, together with the loss of and destruction of traditional lands and habitats, has resulted in reduced access to native foods by Aboriginal people.

Kiwi are flightless birds endemic to New Zealand of the order Apterygiformes. The five extant species fall into the family Apterygidae and genus Apteryx. Approximately the size of a domestic chicken, kiwi are the smallest ratites (which also include ostriches, emus, rheas, cassowaries and the extinct elephant birds and moa).

DNA sequence comparisons have yielded the conclusion that kiwi are much more closely related to the extinct Malagasy elephant birds than to the moa with which they shared New Zealand. There are five recognised species, four of which are currently listed as vulnerable, and one of which is near threatened. All species have been negatively affected by historic deforestation, but their remaining habitat is well protected in large forest reserves and national parks. At present, the greatest threat to their survival is predation by invasive mammalian predators.

The rhea (/ˈriːə/ REE-ə), also known as the ñandú (/njænˈduː/ nyan-DOO) or South American ostrich, is a South American ratite (flightless bird without a keel on the sternum bone) of the order Rheiformes. Rheas are distantly related to the two African ostriches and Australia's emu (the largest, second-largest and third-largest living ratites, respectively), with rheas placing just behind the emu in height and overall size.

Most taxonomic authorities recognize two extant species: the greater or American rhea (Rhea americana), and the lesser or Darwin's rhea (Rhea pennata). The International Union for Conservation of Nature (IUCN) classifies the puna rhea as another species instead of a subspecies of the lesser rhea. The IUCN currently rates the greater and puna rheas as near-threatened in their native ranges, while Darwin's rhea is of least concern, having recovered from past threats to its survival. In addition, the feral population of the greater rhea in Germany appears to be growing. However, control efforts are underway and seem to succeed in controlling the birds' population growth. Similarly to ostriches and emus, rheas are fairly popular livestock and pets, regularly kept and bred on farms, ranches, private parks, and by aviculturists, mainly in North and South America and Europe.

Cassowaries (Indonesian: kasuari; Biak: man suar 'bird strong'; Tok Pisin: muruk; Papuan: kasu weri 'horned head') are flightless birds of the genus Casuarius, in the order Casuariiformes. They are classified as ratites, flightless birds without a keel on their sternum bones. Cassowaries are native to the tropical forests of New Guinea (Western New Guinea and Papua New Guinea), the Moluccas (Seram and Aru Islands), and northeastern Australia.

Three cassowary species are extant. The most common, the southern cassowary, is the third-tallest and second-heaviest living bird, smaller only than the ostrich and emu. The other two species are the northern cassowary and the dwarf cassowary; the northern cassowary is the most recently discovered and the most threatened. A fourth, extinct, species is the pygmy cassowary.

Palaeognathae (/ˌpæliˈɒɡnəθi/; from Ancient Greek παλαιός (palaiós) 'old' and γνάθος (gnáthos) 'jaw') is an infraclass of birds, called paleognaths or palaeognaths, within the class Aves of the clade Archosauria. It is one of the two infraclasses of birds, the other being Neognathae, both of which form Neornithes. Palaeognathae contains five extant orders consisting of four flightless lineages (plus two that are extinct), termed ratites, and one flying lineage, the Neotropic tinamous. There are 47 species of tinamous, five of kiwis (Apteryx), three of cassowaries (Casuarius), one of emus (Dromaius) (another became extinct in historic times), two of rheas (Rhea) and two of ostriches (Struthio). Recent research has indicated that paleognaths are monophyletic but the traditional taxonomic split between flightless and flighted forms is incorrect; tinamous are within the ratite radiation, meaning flightlessness arose independently multiple times via parallel evolution.

There are three extinct groups that are undisputed members of Palaeognathae: the Lithornithiformes, the Dinornithiformes (moas) and the Aepyornithiformes (elephant birds), the latter two of which became extinct in the last 1250 years. There are other extinct birds which have been allied with the Palaeognathae by at least one author, but their affinities are a matter of dispute.

John Latham FRS (27 June 1740 – 4 February 1837) was an English physician, naturalist and author. His main works were A General Synopsis of Birds (1781–1801) and A General History of Birds (1821–1828). He was able to examine specimens of Australian birds that reached England in the final twenty years of the 18th century, and was responsible for providing English names for many of them. He named some of Australia's most famous birds, including the emu, sulphur-crested cockatoo, wedge-tailed eagle, superb lyrebird, Australian magpie, magpie-lark, white-throated needletail and pheasant coucal. Latham has been called the "grandfather" of Australian ornithology. He was also the first to describe the hyacinth macaw from South America.

Emu oil is an oil derived from body fat harvested from certain subspecies of the emu, Dromaius novaehollandiae, a flightless bird indigenous to Australia.

Unadulterated emu oil can vary widely in colour and viscosity anywhere from an off-white creamy texture to a thin yellow liquid, depending on the diet of the emu and the refining method(s) used. Industrially refined emu oil is composed of a minimum of 70% unsaturated fatty acids. The largest component is oleic acid, a monounsaturated omega-9 fatty acid. Emu oil also contains roughly 20% linoleic acid (an omega-6 fatty acid) and 1–2% linolenic acid (an omega-3 fatty acid). Fully refined emu oil has a bland flavour.

Struthionidae (/ˌstruːθiˈɒnədiː/; from Latin strūthiō 'ostrich' and Ancient Greek εἶδος (eîdos) 'appearance, resemblance') is a family of flightless birds, containing the extant ostriches 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 living bird species. The extinct genus Pachystruthio from the Late Pliocene-Early Pleistocene of Eurasia is one of the largest birds ever.

The first species of Struthio appear during the Miocene epoch, though various Paleocene, Eocene, and Oligocene fossils may also belong to the family. Ostriches are classified in the ratite group of birds, all extant species of which are flightless, including the kiwis, emus, and 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 tinamous, so the ostriches are usually classified as the only members of the order, though the IUCN uses a broader classification and includes all "ratites" and tinamous in Struthioniformes.

Dromaius (from greek δρομαίυς "runner") is a genus of ratite present in Australia. There is one extant species, Dromaius novaehollandiae, commonly known as the emu.

In his original 1816 description of the emu, Louis Pierre Vieillot used two generic names; first Dromiceius, then Dromaius a few pages later. Which label is correct has been a point of contention ever since; the latter is more correctly formed, but the convention in taxonomy is that the first name given stands, unless it is clearly a typographical error, as argued by W.B. Alexander. For names published on the same day, or in the same publication, the International Code of Zoological Nomenclature states that both names have equal precedence, and that the Principle of First Reviser (Article 24.2 ) determines which name is to be used. Most modern publications, including those of the Australian government, use Dromaius, with Dromiceius mentioned as an alternative spelling. Misspellings of both forms by later authors have produced further synonyms. The Dromiceius spelling was the basis for Dale Russell's 1972 naming of the dinosaur Dromiceiomimus.

The Tasmanian emu (Dromaius novaehollandiae diemenensis) is an extinct subspecies of emu. It was found in Tasmania, where it had become isolated during the Late Pleistocene. As opposed to the other insular emu taxa, the King Island emu and the Kangaroo Island emu, the population on Tasmania was sizable, meaning that there were no marked effects of small population size as in the other two isolates.

The Tasmanian emu became extinct around 1865 according to the Australian Species Profile and Threats database. This was officially recorded in 1997 when changes to listings of nationally threatened species saw the Tasmanian emu added to the list of species presumed extinct.