The emu is the second-largest living bird, exceeded in height only by the ostrich, and the sole surviving member of its genus following the loss of several island forms after European settlement [BirdLife International 2018; Thomson et al. 2018]. A flightless ratite endemic to Australia, it ranges across most of the continent's grasslands, woodlands, and semi-arid interior, where its nomadic movements and long gut-retention times make it a significant long-distance disperser of seeds [Calviño-Cancela et al. 2006]. This profile examines the emu's biology, its conservation status as a widespread but locally pressured species, and the historical and ongoing dynamics of its relationship with people.
Biology and Identification
The emu is a large, flightless ratite with a long neck and powerful legs adapted for sustained, high-speed running. Adults typically stand between 1.5 and 1.9 m tall and weigh roughly 18–60 kg, with females averaging slightly heavier than males [Davies 1976]. The plumage is shaggy and brown-grey, with a loose, hair-like appearance produced by widely spaced barbs and a double-shafted feather structure in which two rachides emerge from a single follicle. The wings are reduced to small vestigial structures bearing a clawed tip, and their osteology and musculature reflect a lineage in which flight has been lost while the forelimb persists in modified form [Maxwell & Larsson 2007].
Emus are built for terrestrial locomotion. The leg musculature is dominated by large, powerful units such as the gastrocnemius, structured for the high power output required during running, and the pelvic-limb anatomy shows adaptations characteristic of a large cursorial bird [Patak & Baldwin 1993; Patak & Baldwin 1998]. Emus can reach running speeds of around 48 km/h.
The species is omnivorous but predominantly herbivorous, feeding on seeds, fruits, flowers, shoots, and invertebrates. Many seeds pass through the digestive tract intact and are deposited away from the parent plant, a role of particular ecological importance in fragmented and semi-arid landscapes [Calviño-Cancela et al. 2006; Davis et al. 2010].
Breeding involves a notable reversal of typical avian parental roles. After a female lays a clutch of large dark-green eggs in a ground nest, the male undertakes incubation alone for approximately eight weeks, during which he fasts and loses substantial body condition, then guards and rears the chicks for several months after hatching [Davies 1976].
Habitat and Range
The emu is widely distributed across mainland Australia, occupying grasslands, savannas, open woodlands, shrublands, and semi-arid regions [BirdLife International 2018]. It is generally absent from dense closed forest, the most extreme deserts, and heavily urbanised areas, but remains common across much of its natural range. As an adaptation to a variable, semi-arid continent, the emu is highly mobile and nomadic, undertaking movements in response to rainfall and shifting food availability [Davies 1976].
Distribution modelling indicates that the emu's range has shifted over the Holocene and is sensitive to climate: parts of the east coast have become climatically sub-optimal, a change relevant to small, isolated populations at the edge of the species' range [Mehrabi et al. 2021]. Three smaller-bodied island forms — the King Island, Kangaroo Island, and Tasmanian emus — became extinct in the early nineteenth century following hunting and habitat burning by settlers; genetic work indicates these island birds belonged to the same species as the mainland emu rather than representing separate species [Thomson et al. 2018].
In accordance with NRWL sensitive-species policy, specific site locations, corridor routes, and seasonal movement details are not disclosed in this article.
Conservation Status
The emu is listed as Least Concern on the IUCN Red List, reflecting its extremely large range and a population that is not approaching the thresholds for a threatened category [BirdLife International 2018]. The global population is estimated at approximately 630,000–725,000 mature individuals, and the overall population trend is judged to be stable [BirdLife International 2018]. The emu is not listed in any CITES appendix, as international commercial trade is not considered a threat to the species at the global level.
This favourable global assessment, however, masks important regional variation. The smaller-bodied King Island, Kangaroo Island, and Tasmanian island forms were driven to extinction in the early 1800s, and at least one mainland subpopulation in coastal New South Wales is recognised as endangered at the state level, occurring at the climatic margins of suitable emu habitat [Mehrabi et al. 2021]. The species' broad continental distribution is the principal reason its overall status remains secure despite these localised losses [BirdLife International 2018].
Threats
Localised habitat change and fragmentation affect emus at the margins of their range, where clearing for agriculture and altered fire regimes can reduce the connectivity that nomadic birds depend on to track food and water [Mehrabi et al. 2021].
Vehicle collisions and fencing contribute to mortality in settled landscapes. Roads bisecting nomadic movement routes increase roadkill risk, while barrier fencing originally erected to limit crop damage can impede long-distance movement.
Predation of eggs and chicks by introduced predators, particularly red foxes, and by native predators, can suppress recruitment in some areas, an issue of greater consequence for small or isolated populations than for the secure continental population.
Climate-driven range contraction is a longer-term concern for edge populations. Modelling indicates that portions of eastern Australia have become climatically sub-optimal and are projected to remain so, increasing pressure on the already-restricted coastal populations [Mehrabi et al. 2021].
Historically, deliberate culling represented a significant pressure: in 1932, in response to emus damaging wheat crops in the Campion district of Western Australia during a drought-driven influx, Australian authorities deployed soldiers with machine guns in what became known as the "Emu War," an operation widely regarded as ineffective at reducing emu numbers [Britannica 2024].
What Is Being Done
Legal protection. The emu is protected under Australian wildlife legislation, and the secure status of the continental population reflects, in part, the regulation of hunting and culling that followed the unregulated bounty era of the early twentieth century.
Population and distribution research. Continental-scale distribution modelling under past, present, and future climates is used to identify populations at risk, prioritise habitats, and inform conservation planning for edge populations under climate change [Mehrabi et al. 2021]. Tracking studies of emu movements and seed dispersal quantify the species' ecological role and help define the spatial scales at which connectivity must be maintained [Calviño-Cancela et al. 2006; Davis et al. 2010].
Rewilding assessment. Following the nineteenth-century extinction of the Tasmanian emu, researchers have evaluated the feasibility of reintroducing mainland emus to parts of Tasmania, finding that substantial areas retain suitable habitat and land use, and that such an effort could restore ecological and cultural roles if it has community support [Dortch et al. 2023].
Genetic and museum science. Analysis of ancient DNA and historical specimens has clarified the taxonomy and history of the extinct island forms, refining the conservation context and documenting how rapidly small island populations were lost after settlement [Thomson et al. 2018].
How Readers Can Help
Citizen science. Record emu observations through platforms such as eBird and iNaturalist. Verified occurrence records contribute to distribution mapping and to the population monitoring that underpins Red List assessments.
Support habitat connectivity. Back land-management and revegetation programs that maintain connected habitat across agricultural and semi-arid landscapes, which benefits nomadic species that must move to track rainfall and food.
Drive carefully in emu country. In rural areas within emu range, reducing speed at dawn and dusk lowers the risk of collisions with emus crossing roads.
Share accurate information. Promote science-based understanding of the emu's ecological role as a seed disperser and of the distinction between the secure continental population and the smaller, vulnerable edge and island populations, several of which have already been lost.
References
[BirdLife International 2018] BirdLife International. (2018). Dromaius novaehollandiae. The IUCN Red List of Threatened Species 2018: e.T22678117A131902466. https://doi.org/10.2305/IUCN.UK.2018-2.RLTS.T22678117A131902466.en
[Britannica 2024] Encyclopædia Britannica. (2024). Emu War — Australia, casualties, history, summary, and facts. https://www.britannica.com/topic/Emu-War
[Calviño-Cancela et al. 2006] Calviño-Cancela, M., Dunn, R.R., van Etten, E.J.B. & Lamont, B.B. (2006). Emus as non-standard seed dispersers and their potential for long-distance dispersal. Ecography, 29(4), 632–640. https://doi.org/10.1111/j.0906-7590.2006.04677.x
[Davies 1976] Davies, S.J.J.F. (1976). The natural history of the emu in comparison with that of other ratites. In Proceedings of the 16th International Ornithological Congress (pp. 109–120). Australian Academy of Science, Canberra.
[Davis et al. 2010] Davis, R.A., Lohr, C.A. & Roberts, J.D. (2010). Dietary characteristics of Emus (Dromaius novaehollandiae) in semi-arid New South Wales, Australia, and dispersal and germination of ingested seeds. Emu — Austral Ornithology, 113(1), 23–32. https://doi.org/10.1071/MU12061
[Dortch et al. 2023] Dortch, J., Mehrabi, Z., Frankham, G. & Fordham, D.A. (2023). Extinction of the Tasmanian emu and opportunities for rewilding. Global Ecology and Conservation, 41, e02358. https://doi.org/10.1016/j.gecco.2022.e02358
[Maxwell & Larsson 2007] Maxwell, E.E. & Larsson, H.C.E. (2007). Osteology and myology of the wing of the Emu (Dromaius novaehollandiae), and its bearing on the evolution of vestigial structures. Journal of Morphology, 268(5), 423–441. https://doi.org/10.1002/jmor.10527
[Mehrabi et al. 2021] Mehrabi, Z., Mehrabi, S.D., Stuart-Fox, D. & Fordham, D.A. (2021). Past and future potential range changes in one of the last large vertebrates of the Australian continent, the emu Dromaius novaehollandiae. Scientific Reports, 11, 711. https://doi.org/10.1038/s41598-020-79551-0
[Patak & Baldwin 1993] Patak, A.E. & Baldwin, J. (1993). Structural and metabolic characterization of the muscles used to power running in the emu (Dromaius novaehollandiae), a giant flightless bird. Journal of Experimental Biology, 175(1), 233–249. https://doi.org/10.1242/jeb.175.1.233
[Patak & Baldwin 1998] Patak, A.E. & Baldwin, J. (1998). Pelvic limb musculature in the emu Dromaius novaehollandiae (Aves: Struthioniformes: Dromaiidae): Adaptations to high-speed running. Journal of Morphology, 238(1), 23–37. https://doi.org/10.1002/(SICI)1097-4687(199810)238:1%3C23::AID-JMOR2%3E3.0.CO;2-O
[Thomson et al. 2018] Thomson, V.A., Mitchell, K.J., Eberhard, R., Dortch, J., Austin, J.J. & Cooper, A. (2018). Genetic diversity and drivers of dwarfism in extinct island emu populations. Biology Letters, 14(4), 20170617. https://doi.org/10.1098/rsbl.2017.0617