View source for Great bustard

{{Short description|Species of bird}}
{{Speciesbox
| name = Great bustard
| image = Drop fúzatý (Otis tarda) (2416576086).jpg
| status = EN
| status_system = IUCN3.1
| status_ref = <ref name=iucn>{{cite iucn |author=BirdLife International |author-link=BirdLife International |year= 2023 |title= ''Otis tarda'' |page= e.T22691900A226280431 |access-date=12 December 2023}}</ref>
| status2 = CITES_A2 
| status2_system = CITES 
| status2_ref = <ref name=iucn/>
| genus = Otis
| species = tarda
| authority = [[Carl Linnaeus|Linnaeus]], [[10th edition of Systema Naturae|1758]]
| range_map = OtisTardaIUCN2019 2.png
| range_map_caption = Range of ''Otis tarda''{{leftlegend|#00FF00|Breeding|outline=gray}} {{leftlegend|#008000|Resident|outline=gray}} {{leftlegend|#00FFFF|Passage|outline=gray}} {{leftlegend|#007FFF|Non-breeding|outline=gray}}
}}

The '''great bustard''' ('''''Otis tarda''''') is a bird in the [[bustard]] family, and the only living member of the genus ''[[Otis (bird)|Otis]]''.<ref name="IOC">{{cite web| editor1-last=Gill | editor1-first=Frank | editor1-link=Frank Gill (ornithologist) | editor2-last=Donsker | editor2-first=David | editor3-last=Rasmussen | editor3-first=Pamela | editor3-link=Pamela Rasmussen | year=2023 | title=Turacos, bustards, cuckoos, mesites, sandgrouse | work=World Bird List |version= 13.1 | url=https://www.worldbirdnames.org/bow/turacos/ | publisher=International Ornithologists' Union | access-date=12 December 2023}}</ref> It breeds in open grasslands and farmland from northern [[Morocco]], [[South Europe|South]] and [[Central Europe]] to temperate [[Central Asia|Central]] and [[East Asia]]. European populations are mainly resident, but Asian populations [[bird migration|migrate]] farther south in winter. [[Endangered species|Endangered]] as of 2023, it had been listed as a [[Vulnerable species]] on the [[IUCN Red List]] since 1996.<ref name=iucn/>

[[Portugal]] and [[Spain]] now have about 60% of the world's great bustard population.<ref name=HBW/> It was driven to extinction in [[Great Britain]], when the last bird was shot in 1832. Since 1998 The Great Bustard Group have helped reintroduce it into England on [[Salisbury Plain]], a British Army training area.<ref name="RSPB">{{cite web |title=Reintroducing the great bustard to Southern England |url=http://www.rspb.org.uk/whatwedo/projects/details.aspx?id=282720 |access-date=2015-12-26 |publisher=RSPB}}</ref> Here, the lack of public access and disturbance allows them the seclusion they desire as a large, ground-nesting bird.

== Taxonomy ==
The [[genus]] name ''[[Otis (bird)|Otis]]'' was introduced in 1758 by the Swedish naturalist [[Carl Linnaeus]] in the [[10th edition of Systema Naturae|tenth edition]] of his ''[[Systema Naturae]]'';<ref>{{cite book | last=Linnaeus | first=Carl | author-link=Carl Linnaeus | year=1758 | title= Systema Naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis | volume=1 | edition=10th | page=154 | publisher=Laurentii Salvii | location=Holmiae (Stockholm) | language=Latin | url=https://www.biodiversitylibrary.org/page/727061}}</ref> it came from the [[Ancient Greek|Greek]] name {{lang|el|ὠτίς}} ''ōtis''<ref>{{Cite book |last=Jobling |first=James A. |title=Helm Dictionary of Scientific Bird Names |publisher=[[Christopher Helm]] |year=2010 |isbn=978-1-4081-3326-2 |location=London, UK |pages=286 |oclc=659731768}}</ref> used for this species<ref>{{cite web |last1=Liddell |first1=Henry George |last2=Scott |first2=Robert |date=1940 |title=ὠτίς |url=https://www.perseus.tufts.edu/hopper/text?doc=Perseus:text:1999.04.0057:entry=w)ti/s |work=A Greek-English Lexicon |publisher=Perseus Digital Library}}</ref> taken from ''[[Natural History (Pliny)|Natural History]]'' by [[Pliny the Elder]] published around 77 AD which briefly mentions a bird like it, it was also given the name {{lang|el|ωτιδος}} ''ōtidos'' and the [[Latin]] ''aves tardas''{{efn|"proximae iis sunt quas Hispania aves tardas appellat, Graecia ωτιδος damnatas in cibis; emissa enim ossibus medulla odoris taedium extemplo sequitur." [Next to these are the birds that Spain calls ''tardae'' and Greece ''otides'', which are condemned as an article of diet, because when the marrow is drained out of their bones a disgusting smell at once follows.]<ref name=pliny>{{ cite book | translator=Rachham, H. | date=1967 | title=Pliny Natural History III Libri VIII-XI | series=The Loeb Classical Library | location=Cambridge, Massachusetts | publisher=Harvard University Press | pages=328–329 | url=https://archive.org/details/L353PlinyNaturalHistoryIII811/page/n343/mode/2up}}</ref>}} mentioned by the [[Pierre Belon]] in 1555 and [[Ulisse Aldrovandi]] in 1600.<ref>{{ cite book | last=Belon | first=Pierre | author-link=Pierre Belon | date=1555 | title=L'histoire de la natvre des oyseavx : avec levrs descriptions, & naïfs portraicts retirez du natvrel, escrite en sept livres | language=French | location=Paris | publisher=Gilles Corrozet | pages=235–237 | url=https://www.biodiversitylibrary.org/page/43989802}}</ref><ref>{{ cite book | last=Aldrovandi| first=Ulisse | author-link=Ulisse Aldrovandi | year=1637 | origyear=1600 | title=Vlyssis Aldrovandi philosophi ac medici Bononiensis historiam naturalem in gymnasio Bononiensi profitentis, Ornithologiae | volume=2 | language=Latin | location=Bononiae (Bologna, Italy) | publisher=Apud Nicolaum Tebaldinum  | pages=85 | url=https://www.biodiversitylibrary.org/page/53874775}}<!-- the original 1600 edition is here: https://amshistorica.unibo.it/33--></ref>

The specific epithet ''tarda'' is [[Latin]] for "slow" and "deliberate",<ref>{{cite encyclopedia |url=https://www.perseus.tufts.edu/hopper/text?doc=Perseus:text:1999.04.0059:entry=tardus |title=tardus |last1= Lewis |first1= Charlton T. |last2= Short |first2= Charles |dictionary= A Latin Dictionary |publisher= Perseus Digital Library |date = 1879}}</ref> which is apt to describe the typical walking style of the species.<ref name="eol" /> The Latin phrase ''avis tarda'' "slow bird" is the origin of the word ''bustard,'' via Old French ''bistarda''.<ref>{{cite book | last=Turner | first=William | author-link= William Turner (naturalist) | translator=Evans, A.H. | translator-link=Arthur Humble Evans | year=1903 | origyear=1544 | title=Turner on birds: a short and succinct history of the principal birds noticed by Pliny and Aristotle first published by Doctor William Turner, 1544 | publisher=Cambridge University Press | location=Cambridge | language=Latin, English | url=https://archive.org/details/turneronbirdssho00turn/page/n19/mode/2up | pages=xvi, 130–131}}</ref><ref>{{cite book | last=Turner | first=William | author-link= William Turner (naturalist) | year=1544 | title=Avium praecipuarum, quarum apud Plinium et Aristotelem mentio est, brevis et succincta historia | location=Cambridge | publisher=Ioan. Gymnicus| language=Latin | url=https://books.google.com/books?id=s106AAAAcAAJ&pg=PP136| pages=72–73}}</ref>
[[File:Túzokok - panoramio.jpg|thumb|left|A museum display shows male-female sexual dimorphism.]]

== Description ==
[[File:Dabao.jpg|thumb|Captive male great bustard, showing the characteristic long, beard-like feathers and heavy build]]
The adult male great bustard is amongst the [[Flying and gliding animals#Flying and soaring|heaviest living flying animal]]s. A male is typically {{cvt|90|–|105|cm|ftin}} tall, with a length of around {{cvt|115|cm|ftin}} and has a {{cvt|2.1|-|2.7|m|ftin}} wingspan. The male can range in weight from {{cvt|5.8|to|18|kg}}.<ref name=HBW/><ref name=Wood/> The heaviest verified specimen, collected in [[Manchuria]], was about {{cvt|21|kg|lb}},<ref name="Wood" /><ref name="Tetrapod" /> a world record for heaviest flying bird.<ref>{{Cite book|last=Bird, D. M. |title=The Bird Almanac : The Ultimate Guide to Essential Facts and Figures of the World's Birds |year=1999 |isbn=1-55209-323-9|location=Buffalo, N.Y.|oclc=40051530}}</ref> In a study in Spain, one male weighed as much as {{cvt|19|kg|lb}}.<ref name=Alonso2010>{{cite journal |year=2010 |last1=Alonso |first1=J.C. |last2=Magaña |first2=M. |last3=Palacín |first3=C. |last4=Martín |first4=C. |title=Correlates of male mating success in great bustard leks: the effects of age, weight, and display effort |volume=64 |issue=1 |pages=1589–1600 |journal=Behavioral Ecology and Sociobiology |doi=10.1007/s00265-010-0972-6|hdl=10261/76985 |s2cid=8741416}}</ref> Larger specimens have been reported but remain unverified. Average male weights as reported have been fairly variable: in [[Russia]], males weighed a median of {{cvt|9.2|kg|lb}}; in [[Spain]], males weighed a mean of {{cvt|11.62|kg}} during breeding season and {{cvt|9.65|kg}} during non-breeding; in [[Germany]], males weighed a mean of {{cvt|11.97|kg}}; and the [[Guinness World Records]] has indicated that male bustards in [[Great Britain]] weighed an average of {{cvt|13.5|kg}}. Average weight of males is almost an exact match to that of male Kori bustards. Among all flying animals and land birds, male [[Andean condor]]s (''Vultur gryphus'')  may match or exceed the mean body masses of these male bustards but not their maximum weights. Furthermore, male [[swan]]s of the two largest species ([[trumpeter swan|trumpeter]] and [[mute swan|mute]]) may attain a similar average mass depending on season and region.<ref name="CRC2" /><ref name=Alonso2010/><ref name="CRC" /><ref name="Wood" /><ref name="gbgroup" /><ref name="Letters" />  Among both bustards and all living birds, the upper reported mass of this species is rivaled by that of the [[kori bustard]] (''Ardeotis kori''), which, because of its relatively longer tarsi and tail, is both longer and taller on average and is less sexually dimorphic.<ref name=Alonso2010/> In terms of weight ranges reported, the [[great Indian bustard]] (''Ardeotis nigriceps'') also only lags slightly behind these species.<ref name="CRC2" /><ref name="CRC" /><ref name=Wood/>
[[File:What is this ? (45928345425).jpg|thumb|left|Close up of face]]
The great bustard is also arguably the most [[Sexual dimorphism|sexual dimorphic]] extant bird species, in terms of the size difference between males and females. Adult male great bustards measured in Spain weighed on average 2.48 times more than females.<ref>{{Cite journal|last1=Alonso|first1=J. C. |last2=Magaña |first2=M. |last3=Alonso |first3=J. A.|last4=Palacín|first4=C. |last5=Martín|first5=C, A.|last6=Martín|first6=B. |date=2009 |title=The Most Extreme Sexual Size Dimorphism among Birds: Allometry, Selection, and Early Juvenile Development in the Great Bustard (''Otis tarda'') |url=https://academic.oup.com/auk/article/126/3/657-665/5148342 |journal=The Auk |volume=126|issue=3|pages=657–665|doi=10.1525/auk.2009.08233 |hdl=10261/76983 |s2cid=51741160|hdl-access=free}}</ref> Going on mass, the only known bird with a higher dimorphism is the [[green peafowl]] (''Pavo muticus'') as the males are apparently near four times as heavy as females.<ref name="CRC2" /><ref name="Tetrapod" /> The female is about a third smaller in linear dimensions, typically measuring {{cvt|75|to|85|cm|ftin}} in height, about {{cvt|90|cm|ftin}}<ref name=Letters/> in length and {{cvt|180|cm|ftin}} across the wings.<ref name=HBW/><ref name=gbgroup/> Overall, the female's weight can range from {{cvt|3.1|to|8|kg}}.<ref name=gbgroup/> Like male weights, females weights are quite variable as reported: in Germany, females had a mean weight of {{cvt|3.82|kg}}, in Spain, females had a mean weight of {{cvt|4.35|kg}} and in Russia, females reportedly had a median weight of {{cvt|6|kg}}. The latter figure indicates that eastern birds (presumably ''O. t. dybowskii'') are considerably less sexually dimorphic in body mass than in other populations.<ref name=CRC2/><ref name=Alonso2010/><ref name=CRC/> Perhaps because of this physical sexual dimorphism, there is a skewed sex ratio of about 1.5:1 female to male.

[[File:Great BustardLg1438.jpeg|thumb|Mounted specimen of a female, with somewhat more muted tones and a more slender, smaller build than the adult male]]
An adult male is brown above, barred with blackish colouration, and white below, with a long grey neck and head. His breast and lower neck sides are chestnut and there is a golden wash to the back and the extent of these bright colours tending to increase as the male ages. In the breeding season, the male has long white neck bristles, which measure up to {{cvt|12|-|15|cm}} in length, continually growing from the third to the sixth year of life.<ref name=HBW/> In flight, the long wings are predominantly white with brown showing along the edges of the lower primary and secondary feathers and a dark brown streak along the upper-edge of the wing. The breast and neck of the female are buff, with brown and pale colouration over the rest of the plumage rendering it well camouflaged in open habitats. Immature birds resemble the female. The eastern subspecies (''O. t. dybowskii'') is more extensively grey in colour in both sexes, with more extensive barring on the back.<ref name=HBW/> The great bustard has long legs, a long neck and a heavy, barrel-chested body. It is fairly typical of the family in its overall shape and habitat preferences. Three other bustard species overlap in range with this species: the [[MacQueen's bustard|MacQueen's]] (''Chlamydotis macqueenii''), [[Houbara bustard|houbara]] (''Chlamydotis undulata'') and [[little bustard]]s (''Tetrax tetrax''). However, none of these attains the plumage coloration nor approach the body sizes of this species. Thus, the great bustard is essentially unmistakable.

==Distribution and habitat==
[[File:Las Avutardas de Madrid.jpg|thumb|Great bustards in Spain in fairly typical habitat for the species]]
These birds' [[habitat]] is [[grassland]] or [[steppe]] defined by open, flat or somewhat rolling landscapes. They can be found on undisturbed cultivation and seem to prefer areas with wild or cultivated crops such as cereals, vineyards and fodder plants. However, during the breeding season, they actively avoid areas with regular human activity and can be disturbed by agricultural practices. Great bustards are often attracted to areas with considerable insect activity.

The breeding range of the great bustard currently stretches from Portugal to Manchuria, though previously the species bred even further east in Russian Primorsky Krai. As a result of population declines across much of the range, more than half of the global population is now found in central Spain with around 30,000 individuals. Smaller populations are in southern Russia and the Great Hungarian Plain.<ref name=raab>[http://www.grosstrappe.at/en/great-bustard/distribution-and-population.html great bustards Distribution and population numbers International] Technisches Büro für Biologie Mag. Dr. Rainer Raab, 16 January 2018.</ref>
[[File:Drofa (1).jpg|thumb|Adult male great bustard in habitat]]

==Behaviour and ecology ==
The great bustard is gregarious, especially in winter when gatherings of several dozen birds may occur. Male and female groups do not mix outside of the breeding season. The great bustard has a stately slow walk but tends to run when disturbed rather than fly. Running speeds have not been measured but adult females have been known to outrun [[red fox]]es (''Vulpes vulpes''), which can reach a trotting speed of {{cvt|48|km/h|mph}}.<ref name=westcountrywildlife/><ref name=biokids/><ref name=HBW/> Both sexes are usually silent but can engage in deep grunts when alarmed or angered. The displaying adult male may produce some booming, grunting and raucous noises. The female may utter some guttural calls at the nest and brooded young make a soft, trilling call in communication with their mothers.{{citation needed|date=December 2023}}

=== Migration ===
[[File:Großtrappe Great Bustard (Otis tarda), Grenzgebiet Österreich-Slovakei nahe Jarovce (46444745334).jpg|thumb|A great bustard in flight]]
Some individuals in Iberian populations make short seasonal movements of {{cvt|5-200|km}}, particularly males which appear to move in response to higher summer temperatures.<ref>{{Cite journal |last1=Alonso|first1=J. A.|last2=Martín|first2=C. A.|last3=Alonso|first3=J. C. |last4=Morales|first4=M. B.|last5=Lane|first5=S. J.|title=Seasonal Movements of Male Great Bustards in Central Spain |journal=Journal of Field Ornithology |volume=72 |issue=4 |pages=504–508 |doi=10.1648/0273-8570-72.4.504|s2cid=84271738 |date=2001 |doi-access=free}}</ref><ref>{{Cite journal|last1=Alonso|first1=J. C. |last2=Palacín |first2=C. |last3=Alonso |first3=J. A.|last4=Martín|first4=C. A.|date=2009 |title=Post-breeding migration in male great bustards: low tolerance of the heaviest Palaearctic bird to summer heat |journal=Behavioral Ecology and Sociobiology |volume=63 |issue=12|pages=1705–1715|doi=10.1007/s00265-009-0783-9 |s2cid=33383795}}</ref> European populations are sedentary or make irregular movements in response to severe winter weather.<ref>{{Cite journal|last1=Streich|first1=W. J. |last2=Litzbarski |first2=H. |last3=Ludwig|first3=B. |last4=Ludwig|first4=S. |date=2006 |title=What triggers facultative winter migration of Great Bustard (''Otis tarda'') in Central Europe? |journal=European Journal of Wildlife Research |volume=52 |issue=1|pages=48–53 |doi=10.1007/s10344-005-0007-1 |s2cid=23334564}}</ref><ref>{{Cite journal|last=Block|first=B. |date=1996 |title=Wiederfunde von in Buckow ausgewilderten Großtrappen (''Otis t. tarda'' L., 1758) Ringfundmitteilung 6/1995 der Vogelwarte Hiddensee |journal=Naturschutz und Landschaftspflege in Brandenburg |volume=1/2|pages=76–79}}</ref> Populations breeding along the [[Volga]] in Russia migrate around {{cvt|1000|km}} to spend the winter season in [[Crimea]] and Kherson Oblast.<ref>{{Cite journal |last=Watzke |first=H. |date=2001 |title=Der Zug von Großtrappen ''Otis tarda'' aus der Region Saratov (Russland) – erste Ergebnisse der Satellitentelemetrie im Rahmen eines Schutzprojektes |journal=Vogelwelt |volume=122|pages=89–94}}</ref> Populations breeding in northern [[Mongolia]] migrate over {{cvt|2000|km}} to [[Shaanxi]] Province of China.<ref name=Kessler2013>{{Cite journal |last1=Kessler |first1=A. E. |last2=Batbayar |first2=N. |last3=Natsagdorj |first3=T. |last4=Batsuur' |first4=D. |last5=Smith |first5=A. T. |date=2013 |title=Satellite telemetry reveals long-distance migration in the Asian great bustard ''Otis tarda dybowskii'' |journal=Journal of Avian Biology |volume=44 |issue=4|pages=311–320 |doi=10.1111/j.1600-048X.2013.00072.x}}</ref>

Great bustards often gather in larger numbers at pre-migratory sites in order to move collectively to winter grounds. In the [[Iberian Peninsula]], migrating great bustards seem to choose different periods for movements based on sex.<ref name=MoralesAlonso2000>{{cite journal |last1=Morales |first1=M.B. |last2=Alonso |first2=J.C. |last3=Alonso |first3=J.A. |last4=Martín |first4=E. |title=Migration patterns in male Great Bustards (''Otis tarda'') |journal=The Auk |volume=117|issue=2|year=2000 |page=493 |doi=10.1642/0004-8038(2000)117[0493:MPIMGB]2.0.CO;2 |url=https://digital.csic.es/bitstream/10261/77907/1/Morales%20et%20al%20Auk%20117%20%282000%29.pdf |hdl=10261/77907|s2cid=20600263 |hdl-access=free}}</ref><ref name=Alonso2000/><ref name=Alonso2001/><ref name=PalacínAlonso2009/><ref name=PalacínAlonso2011/> No population is known to use the same grounds for wintering and summering.<ref name=birdlife/> Great bustards are strong fliers and reach speeds of {{cvt|48-98|km/h}} during migration.<ref name=Kessler2013/>

===Reproduction===
[[File:BustardDisplay.jpg|thumb|Male Bustard display]]
[[File:Otis tarda MWNH 0041.JPG|thumb|Eggs in the [[Museum Wiesbaden]]]]
The great bustard breeds in March, and a single male may mate with up to five females. Before mating, the males moult into their breeding plumage around January. Males establish dominance in their groups during winter, clashing violently by ramming into and hitting each other with their bills.<ref name=HBW/> Like other bustards, the male great bustard displays and competes for the attention of females on what is known as a [[lek (biology)|lek]]. In this species, the male has a flamboyant display beginning with the strutting male puffing up his throat to the size of a football. He then tilts forwards and pulls his head in so that the long whiskery chin feathers point upwards and the head is no longer visible. He next cocks his tail flat along his back, exposing the normally hidden bright white plumage then he lowers his wings, with the primary flight feathers folded but with the white secondaries fanning out.<ref name=NHM/> The displaying males, who may walk around for several minutes at a time with feathers flared and head buried waiting for hens to arrive, have been described as a "foam-bath" because of their appearance.<ref name=Alonso2010/>

One to three olive or tan coloured, glossy eggs (two eggs being the average) are laid by the female in May or June. The nests, which are shallow scrapes made by the female on dry, soft slopes and plains, are usually situated close to the prior lek location. Nests are situated in sparse clusters, with a study in [[Inner Mongolia]] finding nests at a minimal {{cvt|9|m|ft}} apart from each other. In the same study, nests were placed at mid-elevation on a hill, at about {{cvt|190|to|230|m}}. Nesting sites are typically in dense grassy vegetation about {{cvt|15|to|35|cm}}, likely for protection against predation, with extensive exposure to sunlight.<ref name=Wan2002/> Eggs weigh about {{cvt|150|g}} and are on average {{cvt|79.4|mm}} tall by {{cvt|56.8|mm}} wide. The female incubates the eggs alone for 21 to 28 days. The chicks almost immediately leave the nest after they hatch, although they do not move very far from their mother until they are at least 1 year old. Young great bustards begin developing their adult plumage at about 2 months, and begin to develop flying skills at the same time. They practice by stretching, running, flapping, and making small hops and jumps to get airborne. By three months they are able to fly reasonable distances. If threatened, the young stand still, using their downy plumage, mainly sepia in colour with paler buffy streaks, as camouflage. Juveniles are independent by their first winter, but normally stay with their mother until the next breeding season. Males usually start to mate from 5 to 6 years of age, although may engage in breeding display behaviour at a younger age. Females usually first breed at 2 to 3 years old.<ref name=HBW/><ref name=NHM/>

===Diet===
The species is [[omnivore|omnivorous]], taking different foods in differing seasons. In northwestern Spain in August, 48.4% of the diet of adult birds was green plant material, 40.9% was [[invertebrate]]s and 10.6% was seeds. In the same population during winter, seeds and green plant material constituted almost the entirety of the diet. [[Alfalfa]] is seemingly preferred in the diet of birds from Spain.<ref name=Lane1999/> Other favoured plant life in the diet can include [[legume]]s, [[Brassicaceae|crucifers]], [[Taraxacum officinale|common dandelion]] and [[grape]]s and the dry seeds of [[wheat]] and [[barley]].<ref name=HBW/> Among animal prey, [[insect]]s are generally eaten and are the main food for young bustards in their first summer, though they then switch to the seasonal herbivorous preferences of adults by winter. [[Coleoptera]], [[Hymenoptera]] and [[Orthoptera]] are mainly taken, largely based on availability and abundance. Small [[vertebrate]]s supplement the diet when the opportunity arises.<ref name=HBW/><ref name=Bravo2012>{{cite journal |last1=Bravo |first1=C. |last2=Ponce |first2=C. |last3=Palacín |first3=C. |last4=Alonso |first4=C.J. |title=Diet of young Great Bustards ''Otis tarda'' in Spain: Sexual and seasonal differences |year=2012 |journal=Bird Study |volume=59 |issue=2 |pages=243–251 |doi=10.1080/00063657.2012.662940|bibcode=2012BirdS..59..243B |s2cid=85874066}}</ref> Great bustards sometimes eat toxic [[blister beetle]]s of the genus ''[[Meloe]]'' to self-medicate.<ref name=Bravo2014>{{cite journal |last1=Bravo |first1=C. |last2=Bautista |first2=L.M. |last3=García-París |first3=M. |last4=Blanco |first4=G. |last5=Alonso |first5=J.C. |title=Males of a strongly polygynous species consume more poisonous food than females |year=2014 |journal=PLOS ONE |volume=9 |issue=10 |pages=e111057 |pmid=25337911 |doi=10.1371/journal.pone.0111057 |pmc=4206510 |bibcode=2014PLoSO...9k1057B |doi-access=free}}</ref> increasing sexual arousal of males.<ref name=Heneberg2016/> Some plants selected in the mating season showed in-vitro activity against laboratory models of parasites and pathogens.<ref name=Bautista2022>{{cite journal |year=2022 |last1=Bautista |first1=L.M. |last2=Bolivar |first2=P. |last3=Gómez-Muñoz |first3=M.T. |last4=Martínez-Díaz |first4=R.A. |last5=Andrés |first5=M.F. |last6=Alonso |first6=J.C. |last7=Bravo |first7=C. |last8=González-Coloma |first8=A. |title=Bioactivity of plants eaten by wild birds against laboratory models of parasites and pathogens |journal=Frontiers in Ecology and Evolution |volume=10 |pages=1027201 |doi=10.3389/fevo.2022.1027201 |doi-access=free|hdl=10261/284794 |hdl-access=free }}</ref> There are some differences between the diets of female and male bustards as a result of sexual dimorphism in weight, one of the highest in birds.<ref name=Bravo2024>{{cite journal |last1=Bravo |first1=C.  |last2=Bautista-Sopelana |first2=L.M. |last3=Alonso |first3=J.C. |title=Revisiting niche divergence hypothesis in sexually dimorphic birds: Is diet overlap correlated with sexual size dimorphism? |year=2024 |journal=[[Journal of Animal Ecology]] |volume=93 |issue=4 |pages=460–474 |doi=10.1111/1365-2656.14058|bibcode=2024JAnEc..93..460B |hdl=10261/360371 |hdl-access=free }}</ref>

===Foraging===
In winter the feeding intensity increased and then decreased through the morning in both sexes, and was lower in flocks of males than in flocks of females. This sexual difference is greater where legume availability was smaller in central Spain.<ref name=Bautista2017>{{cite journal |year=2017 |last1=Bautista |first1=L.M. |last2=Bravo |first2=C. |last3=Ponce |first3=C. |last4=Unzúe |first4=D. |last5=Alonso |first5=J.C. |title=Food availability but not sex determines morning foraging area size in the Great Bustard ''Otis tarda'', the most sexually size-dimorphic bird species |journal=Ardeola |volume=64 |issue=2 |pages=289–303 |doi=10.13157/arla.64.2.2017.ra1 |hdl=10261/145769 |s2cid=91068606 |hdl-access=free}}</ref> Males that foraged slightly less intensively than females could compensate with longer periods of foraging and bigger bite size<ref name=Martinez2000>{{cite journal |last1=Martínez |first1=C. |year=2000 |title=Daily activity patterns of Great Bustards ''Otis tarda'' |journal=Ardeola |volume=47 |issue=1 |pages=57–68 |url=http://www.ardeola.org/files/430.pdf}}</ref><ref name=AlonsoMagaña2009>{{cite journal  |last1=Alonso |first1=J. C. |last2=Magaña |first2=M. |last3=Alonso |first3=J. A. |last4=Palacín |first4=C. |last5=Martín |first5=C. |last6=Martín |first6=B. |year=2009 | title=The most extreme sexual size dimorphism among birds: allometry, selection, and early juvenile development in the great bustard (''Otis tarda'') |journal=Auk |volume=126 |issue=3 |pages=657–665 |doi=10.1525/auk.2009.08233 |hdl=10261/76983 |s2cid=51741160 |hdl-access=free}}</ref> that would allow them to obtain enough food relative to their absolute daily energy requirements. The size of morning foraging area is smaller in sites with more legume availability, likely because legumes are the most preferred substrate type.<ref name=Bautista2017/>

===Mortality===
Great bustards typically live for around 10 years, but some have been known to live up to 15 years or more. The maximum known life span for the species was 28 years. Adult males seem to have a higher mortality rate than females due mainly to fierce intraspecies fighting with other males during the breeding season. Many males may perish in their first couple of years of maturity for this reason.<ref name=gbgroup/>

Although little detailed information has been obtained of predators, over 80% of great bustards die in the first year of life and many are victims of predation. Chicks are subject to [[predation]] by the fact that they are ground-dwelling birds which are reluctant to fly. Predators of [[bird egg|eggs]] and hatchlings include [[Bird of prey|raptor]]s, [[corvid]]s, [[hedgehog]]s, [[fox]]es, [[weasel]]s, [[badger]]s, [[marten]]s, [[rat]]s and [[wild boar]]s (''Sus scrofa''). The most serious natural predators of nests are perhaps [[red fox]]es and [[hooded crow]]s (''Corvus cornix'').<ref name=grosstrappe/> Chicks grow very quickly, by 6 months being nearly two-thirds of their adult size, and are predated by [[fox]]es, [[lynx]]es, [[gray wolf|gray wolves]] (''Canis lupus''), [[dog]]s, [[jackal]]s and [[eagle]]s.<ref name=Abdulkarimi>{{cite journal |last1=Abdulkarimi |first1=R. |last2=Abbasnejad |first2=H. |last3=Ahmadi |first3=M. |title=A Note on the breeding of the Great Bustard ''Otis tarda'' on Sootav Plain, Boukan, Northwestern Iran |journal=Podoces |year=2010 |volume=5 |issue=2 |pages=104–106 |url=https://www.researchgate.net/publication/256129796}}</ref> Predation on adult male great bustards has been reportedly committed by [[white-tailed eagle]]s (''Haliaeetus albicilla'') while [[golden eagle]]s (''Aquila chrysaetos'') are potential predators and [[eastern imperial eagle]]s (''Aquila heliaca'') have been known to prey on great bustards (but not likely to include adult males).<ref name= Love>{{cite book |author=Love, J.A. |year=1983 |title=The return of the Sea Eagle |publisher=Cambridge University Press |isbn=0-521-25513-9}}</ref><ref>{{cite journal |author1=Sastre, P. |name-list-style=amp |author2=Ponce, C. |year=2009 |title=Disturbances to great bustards (''Otis tarda'') in central Spain: human activities, bird responses and management implications |journal=European Journal of Wildlife Research |volume=55 |issue=4 |pages=425–432 |doi= 10.1007/s10344-009-0254-7|url= |author3=Palacín, C. |author4=Martín, C. A. |author5=Alonso, J. C.}}</ref><ref>{{cite journal |author1=Horváth, M. |name-list-style=amp |author2=Solti, B. |year=2018 |title=Temporal changes in the diet composition of the Eastern Imperial Eagle (''Aquila heliaca'') in Hungary |journal=Ornis Hungarica |volume=26 |issue=1 |pages=1–26 |doi= 10.1515/orhu-2018-0001|url= |author3=Fatér, I. |author4=Juhász, T. |author5=Haraszthy, L. |author6=Szitta, T. |author7=Bállok, Z. |author8=Pásztory-Kovács, S.|doi-access=free }}</ref> Great bustards of unspecified age and sex have been found amongst [[Eurasian eagle-owl]] (''Bubo bubo'') prey remains in [[Bulgaria]].<ref name=Mitev2006/> A possible act of predation on a great bustard was observed to be committed by a much smaller raptor, the [[western marsh harrier]] (''Circus aeruginosus''), though it was likely that this bustard was "weak or injured" if it was taken alive.<ref>Mirzanejad, H., Gholami, J., & Qashqaei, A. T. (2018). ''Can Marsh Harrier Circus aeruginosus prey on Great Bustard Otis tarda?'' Zoology and Ecology, 28(2), 65-68.</ref> The bold, conspicuous behaviour of the breeding adult male bustard may attract the same large mammalian predators that predate chicks, such as wolves and lynx, while the more inconspicuous female may sometimes be attacked by various predators. However, predation is generally fairly rare for adults because of their size, nimbleness and safety in numbers through social behaviour.<ref name=HBW/><ref name=gbgroup/><ref name=CMS/><ref name=Magana2010/>

Occasionally, other natural causes may contribute to mortality in the species, especially starvation in harsh winter months.<ref name=CMS/> However, major causes of mortality in recent centuries have been largely linked to human activity, as described below.

==Population distribution==

[[File:Bet.jpg|thumb|right|Bustard juvenile]]
As of 2008, the global population numbered between 44,000 and 51,000 birds (Palacin & Alonso 2008), about 38,000 to 47,000 in Europe, with 30,000 or more than half in Spain. Hungary had the next largest Great Bustard population with about 1,555 in the year 2012, followed by Ukraine and Austria. Between 4,200 and 4,500 were found in east Asia.<ref name=raab/> In recent times, there have been steep declines throughout eastern and central Europe and in Asia, particularly in [[Kazakhstan]] and [[Mongolia]].{{citation needed|date=January 2018}}

{| class="wikitable"
|+ Range (2008)
|-
! Presence
! Countries
|-
| Native
| [[Afghanistan]], [[Armenia]], [[Austria]], [[Azerbaijan]], [[Bosnia and Herzegovina]], [[Bulgaria]], [[China]], [[Croatia]], [[Czech Republic]], [[France]], [[Georgia (country)|Georgia]], [[Germany]], [[Greece]], [[Hungary]], [[Iran]], [[Iraq]], [[Italy]], [[Kazakhstan]], [[Moldova]], [[Mongolia]], [[Montenegro]], [[Morocco]], [[North Macedonia]], [[Portugal]], [[Romania]], [[Russia]], [[Serbia]], [[Slovakia]], [[Spain]], [[Syria]], [[Tajikistan]], [[Turkey]], [[Turkmenistan]], [[Ukraine]], [[United Kingdom]], [[Uzbekistan]]
|-
| Regionally extinct
| [[Algeria]], [[Lithuania]], [[Myanmar]], [[Poland]], [[Sweden]], [[Switzerland]], [[Kyrgyzstan]]
|-
| Vagrant
| [[Albania]], [[Belgium]], [[Cyprus]], [[Denmark]], [[Egypt]], [[Finland]], [[Gibraltar]], [[Ireland]], [[Israel]], [[Japan]], [[Korea]], [[Latvia]], [[Luxembourg]], [[Malta]], [[Netherlands]], [[Saudi Arabia]], [[Tunisia]]
|-
| Presence uncertain
| [[Lebanon]], [[Pakistan]]
|}

Sizeable populations exist in [[Spain]] (23,055 birds), [[Russia]] (8,000 birds), [[Turkey]] (800–3,000 birds), [[Portugal]] (1,435 birds) and [[Mongolia]] (1,000 birds). In [[Germany]] and [[Austria]] the populations are small (Germany 2016: 232 birds; Austria 2012: 335 birds) but steadily growing for about two decades.<ref>{{cite web|title=2016: 232 Großtrappen in Deutschland|publisher=Förderverein Großtrappenschutz e.V.|url=http://info.grosstrappe.de/2016-232-grosstrappen-in-deutschland/|url-status=dead|access-date=2016-04-03|archive-url=https://web.archive.org/web/20160403174449/http://info.grosstrappe.de/2016-232-grosstrappen-in-deutschland/|archive-date=2016-04-03|date=2016|language=de}}</ref><ref>[https://archive.today/20130906035021/http://www.lebensministerium.at/umwelt/natur-artenschutz/life-natur/life-projekte_aktuell/grosstrappe.html "Zahl der Trappen im Nordburgenland hat sich fast vervierfacht"] {{in lang |de}}. Lebensministerium.at. Retrieved 6 September 2013.</ref> Elsewhere, the populations are declining because of habitat loss throughout its range. A sizeable population also exists in [[Hungary]] (1,100–1,300 birds) where the Eastern European steppe zone ends, near [[Dévaványa]] town and also in the [[Hortobágy National Park]], [[Nagykunság]] and [[Nagy-Sárrét]] regions. The population is down from a population of 10,000–12,000 before the [[Second World War]].

Agroenvironment schemes as unirrigated legumes fostered a population increase of great bustards in [[Castilla y Leon]], central Spain.<ref name=Martín2012>{{cite journal  |last1=Martín |first1=C.A. |last2=Martínez |first2=C. |last3=Bautista |first3=L.M. |last4=Martín |first4=B. |year=2012 |title=Population increase of the great bustard "Otis tarda" in its main distribution area in relation to changes in farming practices |journal=Ardeola |volume=59 |pages=31–42 |doi=10.13157/arla.59.1.2012.31 |hdl=10261/67377 |s2cid=85775630 |url=
https://digital.csic.es/bitstream/10261/67377/6/Martin%20Ardeola59%20p31%202012.pdf}}</ref>

==Threats and conservation status==
[[File:Otis tarda 181119858.jpg|thumb|left|Adult great bustards.]]
The great bustard is classified as vulnerable at the species level. There are myriad threats faced by great bustards. Increasing human disturbance could lead to habitat loss caused by the ploughing of grasslands, intensive agriculture, [[afforestation]], increased development of irrigation schemes, and the construction of roads, power lines, fencing and ditches. Mechanisation, chemical [[fertilizer]]s and [[pesticide]]s, fire and predation by dogs are serious threats for chicks and juveniles, and hunting of adults contributes to high mortality in some of their range countries. Agricultural activity is a major disturbance at nest and, in Hungary, few successful nests are found outside of protected areas.<ref name=CMS/>

Bustards, despite their large size, are able to fly at high speed and are often mutilated or killed by overhead electricity cables, which are placed in the West Pannonia region of Eastern Austria and Western Hungary just at their flying height. The electricity companies affected have buried part of the dangerous cables, and have marked remaining aerial parts with fluorescent markers to warn off the birds. These measures have rapidly reduced bustard mortality.<ref name=CMS/><ref name="RaabSchütz2011"/> Bustards are also occasionally killed by collisions with automobiles or by entanglement in wires.<ref name=CMS/>

[[File:Great Bustard woodcut in Bewick British Birds 1797.jpg|thumb|right|[[Wood engraving]] by [[Thomas Bewick]] in his ''[[A History of British Birds]]'', 1797; he was concerned about their probable local extinction. A horseman and greyhound gallop after another bustard in the background.]]

The great bustard was formerly native in [[Great Britain]] and a bustard forms part of the design of the [[Wiltshire]] [[Coat of arms|Coat of Arms]] and as [[supporter]]s for the [[Cambridgeshire]] arms.<ref name=Cambridgeshire/> As early as 1797, the naturalist and wood engraver [[Thomas Bewick]] commented in his ''[[A History of British Birds]]'' that "Both this [the little bustard] and the Great Bustard are excellent eating, and would well repay the trouble of domestication; indeed, it seems surprising, that we should suffer these fine birds to be in danger of total extinction, although, if properly cultivated, they might afford as excellent a repast as our own domestic poultry, or even as the Turkey, for which we are indebted to distant countries."<ref>{{cite book |last1=Bewick |first1=Thomas |title=A History of British Birds. Volume 1: Land Birds |date=1847 |orig-year=1804 |publisher=R. E. Bewick |location=Newcastle |page=372}}</ref> Bewick's prediction was correct; the great bustard was hunted out of existence in Britain by the 1840s.

In 2004, a project overseeing the reintroduction to [[Salisbury Plain]] in Wiltshire using eggs taken from [[Saratov Oblast|Saratov]] in Russia was undertaken by The Great Bustard Group,<ref>{{Cite web|url=http://greatbustard.org/|title=Home|website=Greatbustard.org|access-date=8 October 2022}}</ref> a UK Registered Charity that aims to establish a self-sustaining population of great bustards in the UK. The reintroduced birds have laid eggs and raised chicks in Britain in 2009 and 2010. Although the great bustard was once native to Britain, great bustards are considered an alien species under English law.<ref name=BBCNews/> The reintroduction of the great bustard to the UK by the Great Bustard Group is being carried out in parallel with researchers from the [[University of Bath]] who are providing insight into the habitat of native great bustard populations in Russia and Hungary. On January 19, 2011, it was announced that the Great Bustard Project had been awarded EU [[The LIFE Programme|LIFE+]] funding, reportedly to the tune of £1.8 million.<ref name=BBCNews2011/> By 2020 the population in Wiltshire exceeded 100 birds.<ref>{{cite web | url=https://www.birdguides.com/articles/great-british-bustards | title=Great British bustards|website=Birdguides.com | date=8 June 2022}}</ref> In Hungary, where the species is the [[List of national birds|national bird]], great bustards are actively protected. The Hungarian authorities are seeking to preserve the long-term future of the population by active protection measures; the area affected by the special ecological treatment had grown to {{convert|15|km2|sqmi|abbr=on}} by the summer of 2006.{{Disputed inline|National bird status, preservation|date=November 2017}}

Under the auspices of the [[Bonn Convention|Convention on Migratory Species of Wild Animals (CMS)]], also known as the [[Bonn Convention]], [[Great Bustard Memorandum of Understanding|the Memorandum of Understanding (MoU) on the Conservation and Management of Middle-European Populations of the Great Bustard]] was concluded and came into effect on June 1, 2001. The MoU provides a framework for governments, scientists, conservation bodies and others to monitor and coordinate conservation efforts in order to protect the middle-European populations of the great bustard.

==Notes==
{{Notelist}}

==References==
{{Reflist|refs=
<ref name=Alonso2000>{{cite journal |last1=Alonso| first1=Juan C.| title=Partial Migration, and Lek and Nesting Area Fidelity in Female Great Bustards| last2=Morales| first2=Manuel B.| last3=Alonso| first3=Javier A.|journal=The Condor| volume=102| issue=1| year=2000| pages=127| issn=0010-5422| doi=10.1650/0010-5422(2000)102[0127:PMALAN]2.0.CO;2| hdl=10261/77120| s2cid=44041490| hdl-access=free}}</ref>

<ref name=Alonso2001>{{cite journal|last1=Lane|first1=Simon J.|last2=Alonso|first2=Juan C.|last3=Martín|first3=Carlos A.|title=Habitat preferences of great bustard ''Otis tarda'' flocks in the arable steppes of central Spain: are potentially suitable areas unoccupied?|journal=Journal of Applied Ecology|volume=38|issue=1|year=2001|pages=193–203|issn=0021-8901|doi=10.1046/j.1365-2664.2001.00577.x|doi-access=free|bibcode=2001JApEc..38..193L }}</ref>

<ref name=BBCNews>{{Cite web |url=http://news.bbc.co.uk/1/hi/england/wiltshire/8079310.stm |title=New bustard chicks a 'huge step' |publisher=BBC |date=2 June 2009}}</ref>

<ref name=BBCNews2011>{{Cite web |url=https://www.bbc.co.uk/news/uk-england-wiltshire-12218959 |title=Salisbury Plain great bustard project EU funding boost |publisher=BBC |date=19 January 2011}}</ref>

<ref name=biokids>{{cite web |url=http://www.biokids.umich.edu/critters/Vulpes_vulpes/ |title=BioKIDS – Kids' Inquiry of Diverse Species, Critter Catalog, Vulpes vulpes, red fox |website=Biokids.umich.edu |date=27 September 2007 |access-date=21 August 2012}}</ref>

<ref name=birdlife>{{cite web |url=http://www.birdlife.org/datazone/speciesfactsheet.php?id=2760 |title=Species factsheet: Otis tarda |year=2012 |website=Birdlife.org |publisher=BirdLife International |access-date=21 August 2012}}</ref>

<ref name=Heneberg2016>{{cite journal |last1=Heneberg |first1=P. |title=On Otis tarda and Marquis de Sade: what motivates male Great Bustards to consume Blister Beetles (Meloidae)?  |year=2016 |journal=Journal of Ornithology |volume=57 |issue=4 |pages=1123–1125  |doi=10.1007/s10336-016-1369-8 |s2cid=17325635}}</ref>

<ref name=Cambridgeshire>{{cite web |title=Cambridgeshire County Council Arms |url=http://www.calh.org.uk/documents/HistoryofCambridgeshireCountyCouncilArms.pdf |archive-url=https://web.archive.org/web/20120424154822/http://www.calh.org.uk/documents/HistoryofCambridgeshireCountyCouncilArms.pdf |archive-date=24 April 2012 |url-status=dead}}</ref>

<ref name=CMS>{{cite web |last=Bankovics |first=A. |url=http://www.cms.int/sites/default/files/document/Inf_05_2_NationalWorkProgramme_Hungary_0.pdf |title=Great Bustard Work Program of Hungary |website=Cms.int}}</ref>

<ref name=CRC>{{cite book |title=CRC Handbook of Avian Body Masses |editor-first=John B. Jr. |editor-last=Dunning |publisher=CRC Press |year=1992 |isbn=978-0-8493-4258-5}}</ref>

<ref name=CRC2>{{cite book |title=CRC Handbook of Avian Body Masses |edition=2nd |editor-first=John B. Jr. |editor-last=Dunning |publisher=CRC Press |year=2008 |isbn=978-1-4200-6444-5}}</ref>

<ref name=eol>{{cite encyclopedia |url=http://eol.org/pages/915364/overview |title=Great Bustard (Otis tarda) – Information on Great Bustard | encyclopedia=Encyclopedia of Life |access-date=21 August 2012}}</ref>

<ref name=gbgroup>{{cite web |url=http://greatbustard.org/about-the-birds/ |title=What are Great Bustards? |publisher=Great Bustard Group |access-date=21 June 2012 |archive-date=12 November 2017 |archive-url=https://web.archive.org/web/20171112112442/http://greatbustard.org/about-the-birds/ |url-status=dead }}</ref>

<ref name=grosstrappe>{{cite web |url=http://www.grosstrappe.at/en/great-bustard/threats.html |title=Threats |website=Grosstrappe.at}}</ref>

<ref name=HBW>{{cite book |title=Handbook of the Birds of the World |last1=del Hoyo |first1=J. | last2=Elliot |first2=A. | last3=Sargatal |first3=J. | year=1996 |publisher=[[Lynx Edicions]] |location=[[Barcelona]] |isbn=978-84-87334-20-7|volume=3|title-link=Handbook of the Birds of the World}}</ref>

<ref name=Lane1999>{{cite journal |last1=Lane |first1=S.J. |last2=Alonso |first2=J.C. |last3=Alonso |first3=J.A. |last4=Naveso |first4=M.A. |title=Seasonal changes in diet and diet selection of great bustards (''Otis t. tarda'') in north-west Spain |year=1999 |journal=Journal of Zoology |volume=247 |issue=2 |pages=201–214 |doi=10.1111/j.1469-7998.1999.tb00984.x}}</ref>

<ref name=Letters>{{cite book |last=Payne-Galleway |title=Letters to Young Shooters on the Choice and Use of a Gun |publisher=General Books LLC |year=2009 |isbn=978-1-150-35645-2}}</ref>

<ref name=Magana2010>{{cite journal |last1=Magaña |first1=M. |last2=Alonso |first2=J.C. |last3=Martín |first3=C.A. |last4=Bautista |first4=L.M. |last5=Martín |first5=B. |year=2010 |title=Nest-site selection by Great Bustards Otis tarda suggests a trade-off between concealment and visibility |journal=Ibis |volume=152 |issue=1 |pages=77–89 |doi=10.1111/j.1474-919X.2009.00976.x|hdl=10261/39088}}</ref>

<ref name=Mitev2006>{{cite journal |last1=Mitev |first1=I. |last2=Boev |first2=Z.|year=2006 |title=Хранителен спектър на бухала (Bubo bubo (L., 1758)) (Aves: Strigiformes) в две холоценски находища от Североизточна България |trans-title=Food spectrum of the owl (Bubo bubo (L., 1758)) (Aves: Strigiformes) in two Holocene deposits of northeastern Bulgaria |journal=Historia Naturalis Bulgarica |language=bg |volume=17 |pages=153–165}}</ref>

<ref name=NHM>{{cite web |url=http://www.nhm.ac.uk/nature-online/species-of-the-day/biodiversity/endangered-species/otis-tarda/index.html |title=''Otis tarda'' (great bustard) |publisher=Natural History Museum |location=London |website=Nhm.ac.uk |access-date=21 August 2012}}</ref>

<ref name="PalacínAlonso2009">{{cite journal|last1=Palacín|first1=Carlos|last2=Alonso|first2=Juan C.|last3=Alonso|first3=Javier A.|last4=Martín|first4=Carlos A.|last5=Magaña|first5=Marina|last6=Martin|first6=Beatriz|title=Differential Migration by Sex in the Great Bustard: Possible Consequences of an Extreme Sexual Size Dimorphism|journal=Ethology|volume=115|issue=7|year=2009|pages=617–626|issn=0179-1613|doi=10.1111/j.1439-0310.2009.01647.x|bibcode=2009Ethol.115..617P }}</ref>

<ref name="PalacínAlonso2011">{{cite journal|last1=Palacín|first1=Carlos|last2=Alonso|first2=Juan C.|last3=Alonso|first3=Javier A.|last4=Magaña|first4=Marina|last5=Martín|first5=Carlos A.|title=Cultural transmission and flexibility of partial migration patterns in a long-lived bird, the great bustard Otis tarda|journal=Journal of Avian Biology|volume=42|issue=4|year=2011|pages=301–308|issn=0908-8857|doi=10.1111/j.1600-048X.2011.05395.x|s2cid=73664186}}</ref>

<ref name="RaabSchütz2011">{{cite journal|last1=Raab|first1=Rainer|last2=Schütz|first2=Claudia|last3=Spakovszky|first3=Péter|last4=Julius|first4=Eike|last5=Schulze|first5=Christian H.|title=Underground cabling and marking of power lines: conservation measures rapidly reduced mortality of West-Pannonian Great Bustards Otis tarda|journal=Bird Conservation International|volume=22|issue=3|year=2011|pages=299–306|issn=0959-2709|doi=10.1017/S0959270911000463|doi-access=free}}</ref>

<ref name=Tetrapod>{{cite web |last=Naish |first=Darren |date=6 April 2010 |url=http://scienceblogs.com/tetrapodzoology/2010/04/the_great_bustard_returns.php |title=The Great bustard returns – Tetrapod Zoology |website=scienceblogs.com |access-date=21 August 2012 |url-status=dead |archive-url=https://web.archive.org/web/20111123013241/http://scienceblogs.com/tetrapodzoology/2010/04/the_great_bustard_returns.php |archive-date=23 November 2011}}</ref>

<ref name=Wan2002>{{cite journal |last1=Wan |first1=D |last2=Gao |first2=W. |last3=Zhao |first3=J. |last4=Wang |first4=H. |last5=Cheng |first5=J. |year=2002 |title=On nest-site selection of ''Otic {{sic}} tarda'' |volume=13 |issue=11 |pages=1445–1448 |journal=Ying yong sheng tai xue bao [The journal of applied ecology / Zhongguo sheng tai xue xue hui, Zhongguo ke xue yuan Shenyang ying yong sheng tai yan jiu suo zhu ban] |pmid=12625004}}</ref>

<ref name=westcountrywildlife>{{cite web |url=http://www.westcountrywildlife.com/greatbustard.htm |title=Great Bustard – Wildlife In The Westcountry |website=Westcountrywildlife.com |access-date=21 August 2012 |archive-url=https://web.archive.org/web/20110726031150/http://www.westcountrywildlife.com/greatbustard.htm |archive-date=26 July 2011 |url-status=dead}}</ref>

<ref name=Wood>{{cite book |last=Wood |first=Gerald |title=The Guinness Book of Animal Facts and Feats |year=1983 |publisher=Guinness Superlatives |isbn=978-0-85112-235-9 |url-access=registration |url=https://archive.org/details/guinnessbookofan00wood}}</ref>
}}

==Further reading==
* {{cite book |last=Gorman |first=Gerard |year=1996 |title=The Birds of Hungary |location=London |publisher=Helm (A&C Black) |isbn=978-0-7136-4235-3}}
* {{cite book |title=Unknown Europe |last=Meissner |first=Hans Otto |author-link=Hans-Otto Meissner |others=trans. Florence and Isabel McHugh |year=1963 |publisher=Blackie & Sons |location=London and Glasgow |pages=125–139}}

==External links==
{{Commons category|Otis tarda}}
{{Wikispecies|Otis tarda}}
* {{ARKive|3=Great bustard ''(Otis_tarda)''}}
* [http://www.cms.int/species/otis_tarda/otis_tarda_bkrd.htm CMS Great Bustard Memorandum of Understanding]
* {{BirdLife|22691900|Otis Tarda}}
* [https://www.flickr.com/search/groups/?w=42637302@N00&q=Otis+tarda&m=pool Field Guide Page on Flickr]
* {{InternetBirdCollection|great-bustard-otis-tarda}}
* {{VIREO|great+bustard}}

{{Otididae}}
{{Taxonbar|from=Q171655}}
{{Authority control}}

[[Category:Otididae|great bustard]]
[[Category:Birds of Eurasia]]
[[Category:Birds described in 1758|great bustard]]
[[Category:Taxa named by Carl Linnaeus|great bustard]]