Data Zone
Justification of Red List category
This species has suffered rapid population reductions across most of its range owing to the loss, degradation and fragmentation of its habitat due to agricultural intensification and industrial expansion (including energy development), with climate change exacerbating these effects through increased frequency of extreme weather events and wildfires. In addition, illegal killing, elevated predation rates and disturbance are contributing to declines, with increased access to and division of the species' habitats by expanded and upgraded road networks compounding these threats. Population declines are currently estimated to be rapid, but are projected to become very rapid in the near future and over the next three generations. Accordingly Great Bustard is assessed as Endangered.
Population justification
Two revised estimates of the global population were published in 2022. Alonso and Palacín (2022) collated national estimates from across the species’ range, producing a total of 30,693–35,402 birds. Kessler (2022) did the same but included the results of more recent surveys in Asia and elsewhere, reporting a total of 29,060–32,449 birds. Combining these sources by using the most recent national estimates from them both, and an even more recent estimate from Morocco (Alonso et al. 2023), yields a figure of 29,638–33,027, rounded to a range of 29,600-33,000.
A breakdown of this total includes (broadly from west to east): for the western subspecies O. t. tarda, 72-78 birds in Morocco in 2022 (Alonso et al. 2023), 939 birds in Portugal in 2021 (Instituto da Conservação da Natureza e das Florestas and Liga para a Protecção da Natureza 2018 [unpublished data]), 22,000-24,000 birds in Spain in 2019 (Palacín and Alonso 2021), 315 birds in Germany in 2022 (LIFE Great Bustard 2022), 634 birds in West Pannonia (which here includes Austria, western Hungary, and Slovakia) in 2022 (LIFE Great Bustard 2022), 1,495 individuals in East Pannonia (which here includes central and eastern Hungary, Romania and Serbia) in 2022 (LIFE Great Bustard 2022), 559-780 individuals in Türkiye in 2019 (Özgencil et al. 2022), 33-35 birds in Iran in 2016-2017 (Abdulkarimi 2022), 225-300 birds in Ukraine in 2015 (Andryushchenko 2009, Beskaravainyi 2015 per Kessler 2022), 1,870 birds in European Russia in 2021 (Oparina and Oparin 2021), 179-364 birds in Central Asia (including Asian Russia and Kazakhstan) in 2014-2016 (Kornev and Gavlyuk 2019, Rustamov 2022, Kashkarov et al. 2022, Muratov and Talbonov 2022, Kulagin 2022, Shakula et al. 2022a, Koshkin et al. 2022, Kessler and Bidashko 2022, Nefedov 2022, per Kessler 2022), and 17 individuals in north-west China in 2016 (Wang and Yang 2022); for the eastern subspecies O. t. dybowskii, 1,300-2,200 individuals across its range, which includes Mongolia, south-east Russia and northeast China (Kessler et al. 2021, Kessler and Batbayar 2023). Based on the above numbers, the species' Spanish population currently represents c. 74% of its global population size.
A reintroduction scheme is underway in the United Kingdom, with 67 individuals in 2021 (Kessler et al. 2021) and almost 100 individuals in 2022 (Great Bustard Group 2023), but this is currently considered a managed subpopulation and does not form part of the assessed population as yet.
Trend justification
Substantial evidence exists documenting the historical decline and disappearance of this species across much of its range, with recent data collated by Alonso and Palacín (2022) and Kessler (2022) confirming that this decline is continuing. Alonso and Palacín (2022) estimated that the global population declined by c. 34% (30–38%) between 2005 and 2018, with an annual rate of -3.23%; declines were highest in China and European Russia (89% and 72%, respectively), with significant declines also seen in Portugal (-50%), and in Spain (-28%). The latter was noted as an important change compared to previous national trend data which previously estimated the population in the country as either stable to slightly increasing. Repeating this analysis including the more updated national population estimates from Kessler (2022) yields a decline of c. 36% (25–46%) between 2004 and 2019, which equates to an annual decline of c. 3% (2–4%). Extrapolating this rate of decline to three generation lengths suggests a decrease of c. 65% (49–75%), however, these calculations assume that the rate of decline has been constant over time, which is not the case for this species. Similarly, in the species’ major eastern European stronghold, population declines accelerated to reach a rate of reduction of c. 70% (Andryushchenko 2020, Oparin and Oparina 2020).
The accelerating rate of decline in recent years means it is not justifiable to backcast current rates of decline into the past, but it is reasonable to extrapolate them into the future. As such, a rate of population reduction of 49–75% is assigned to the three-generation period between 2004 and 2040, and the range of 25-46% is kept for the past three generations.
Key threats, such as increased habitat degradation, fragmentation, and loss due to land use change and agricultural expansion and intensification, as well as unintentional poisoning and collisions with powerlines, have or are expected to increase in both Europe and Asia, and could be compounded by climate change (Kessler 2021, Kessler and Collar 2022, Kashkarov et al. 2023, Silva et al. 2023). Illegal hunting also remains a potent threat (Kessler 2022, Özgencil et al. 2022). Accordingly the current rate of decline is projected to continue into the future, at a rate of 50-79% over three generations.
Historically, the species' breeding range extended across the Eurasian steppes, from Portugal all the way to the Pacific coast of Russia and the Korean Peninsula (Kessler 2022, Kessler and Batbayar 2023). Currently, this species breeds in Portugal, Spain, Austria, Germany, Slovakia, Hungary, Serbia, Romania, Türkiye, Russia, Ukraine, Kazakhstan, and China, as well as in Morocco, Iran (West Azerbaijan province [Barati et al. 2015]), western Siberia, western and northern Kazakhstan, and western Mongolia where only isolated populations remain, many of which are at high risk of extinction (Alonso and Palacín 2022, Kessler 2022, Kessler and Batbayar 2023). A reintroduction scheme is currently taking place in the United Kingdom.
The species' range is becoming increasingly disjunct, with rapid declines and population extinctions in parts of eastern and central Europe (Bulgaria, Poland, Moldova, Czechia), and the species is considered at risk of extinction or already extirpated in the majority of areas between west-central Türkiye to Nei Mongol (China) (Palacín and Alonso 2008, Kessler and Collar 2022, Kessler and Batbayar 2023). Over the past half century, the species has only rarely been sighted in Kyrgyzstan, Tajikistan and Azerbaijan, where it once bred (M. Kessler in litt. 2016). Despite occupying a large proportion of the species' range, the population in Central Asia now only represents 1% of the global population (Kessler 2022).
These declines have been accompanied by a range contraction, due to the disappearance of smaller populations across the species' range, as recently highlighted in Keller et al. (2020).
Nevertheless, thanks to considerable conservation effort, the species' breeding population has increased in West and East Pannonia, and in Romania, due to the dispersal of the Pannonian populations (Alonso and Palacín 2022, Kessler 2022).
Most populations of the western subspecies are at least partially migratory, depending on weather conditions, and occur on passage or in winter in Ukraine, Iraq, Kazakhstan and Uzbekistan (Y. Andryushchenko in litt. 1999, 2017; Kessler 2015, 2022; M. Kessler in litt. 2016, K. Ararat in litt. 2023). Birds from northern Central Asia used to overwinter in large numbers in Turkmenistan, as well as Azerbaijan and north-east Iran, but sightings are now rare in these countries, due to the crash of the Central Asian population in the 20th century (Kessler and Smith 2014). Southern Central Asian breeding grounds in southern and south-eastern Kazakhstan, and areas in Uzbekistan, however, still serve as staging grounds and sometimes as overwintering sites, and these currently hold the largest numbers of Great Bustards during migration (Kessler 2022). The eastern subspecies, which breeds in Mongolia, eastern Russia, and north-east China is fully migratory, spending four months on migratory stopovers and four months on wintering grounds, which used to extend to the Korean Peninsula and can still be found as far south as central China, although more birds are now overwintering in breeding grounds in northern China (Kessler et al. 2013, M. Kessler in litt. 2016, Kessler and Batbayar 2023).
This species was originally mainly associated with Eurasian steppe, but it has acclimated to agricultural landscapes (M. Kessler in litt. 2016), and can now be found in open, flat or somewhat rolling landscapes, usually with short sward height and a mixture of preferably low-intensity farmland activities and crops (cereals, vineyards, fodder plants, as well as fallow fields, pastureland and steppic grassland) (J. C. Alonso in litt. 2012, Collar and Garcia 2020). In Iberia, it also occurs in Cork Oak Quercus suber and Holm Oak Q. ilex dehesas, and in olive groves (Collar and Garcia 2020). In Asia, it can also be found in Artemisia and Stipa steppes, mountain foothills and in semi-desert habitats (Gubin 2007 per Kessler and Batbayar 2023). The eastern subspecies inhabits both open steppe and forest steppe, including small forest openings, and using trees as sources of shade and food (Mel’nikov and Popov 2000 per Kessler and Batbayar 2023, Raab et al 2014, M. Kessler in litt. 2016), and are more often found in wet habitats such as river islands and moist meadows (Kozlova 1975, Ponomareva 1986, Goroshko 2002, Goroshko 2008 per Kessler and Batbayar 2023).
Its diet comprises invertebrates, plants and seeds, as well as small vertebrates, including mammals, reptiles, amphibians and birds (Collar and Garcia 2020, Kessler and Batbayar 2023).
Areas with little or no disturbance and abundant supply of insects are required for successful breeding (Y. Andryushchenko in litt. 1999). Nest sites are selected in grassland, fallow or cereal fields (Rocha et al. 2013) (primarily alfalfa in Central Europe and wheat in Russia, Mongolia and Kazakhstan [M. Kessler in litt. 2016]) in areas of low patch-type diversity, far from human infrastructure, and with good horizontal visibility (Magaña et al. 2010). The eastern subspecies nests primarily in agricultural mosaics, open steppe, and adjacent to forest edge (Kessler 2015), and utilises areas around international borders for both breeding and migratory stopover sites, as well as, possibly, wintering grounds too (Kessler and Batbayar 2023). The species exhibits highly variable migratory behaviour across populations, including obligate winter migrants (majority of Asia), short-distance migrants (Iran), facultative migrants (central European populations) and partial winter and summer migrants with differential migratory pattern by sex (Iberian populations) (Morales et al. 2000, Alonso et al. 2000; Palacín et al. 2009, 2011; Kessler 2022). The species gathers in large wintering flocks in Central Asia (Kessler 2022).
Key threats are increased habitat degradation, fragmentation and loss due to agricultural intensification, land-use changes such as agricultural expansion and intensification, and infrastructure development, which have accelerated in both Europe and Asia, and could be compounded by climate change and the species' naturally low reproductive rate. Collisions with powerlines are expected to increase with the expansion of the renewable energy network across vast swathes of the species’ Asian range (Nagy 2018, Alonso and Palacín 2022, Kessler 2022, Kashkarov et al. 2023, Silva et al. 2023).
Changes in land use have the potential to increase following land privatisation in eastern Europe (S. Nagy in litt. 1999, 2007, Nagy 2009) and Central Asia and is occurring in China (Chan and Goroshko 1998, M. Kessler in litt. 2016). Habitat loss, degradation and fragmentation continues as a result of the ploughing of grasslands, overgrazing, afforestation (Sterbetz 2000) and the increasing development of irrigation schemes, roads, powerlines, fencing, and ditches (Nagy 2018). Agricultural machinery, chemical fertilisers, fire and predation all contribute to high mortality in eggs, chicks, juveniles and incubating females, while chemical pesticides, also lower the food resources needed for chick development (Nagy 2009, 2018; Rocha et al. 2013, Alonso and Palacín 2022, Kessler 2022). Unintentional poisoning from agricultural chemicals has recently increased in Eastern Europe (e.g. Kessler 2021), and unintentional effects on the species' endocrine system from agrochemicals may lower its reproductive rate and success (Kessler and Batbayar 2023). The expansion of urban and industrial areas can also lead to habitat loss, and road networks can also degrade the species' habitat as well as create disturbance for the species (Osborne et al. 2001, Palacín 2007, Torres et al. 2011, Raab et al. 2014). Disturbance, either during the display or nesting periods, reduces the reproductive rate of the species (Nagy 2018).
Hunting is a major threat in Morocco, Türkiye, China, Kazakhstan, Uzbekistan and Mongolia (Y. Andryushchenko in litt. 1999, Chan and Goroshko 1998, P. Goriup in litt. 2007, Karakaş and Akarsu 2009; M. Kessler in litt. 2012, 2016; M. M. Karataş in litt. 2016), and is expected to intensify as the paved road network expands, increasing access to the species' habitats (e.g. in Mongolia), but also as access to firearms becomes easier (Kessler and Batbayar 2023). International tourists are known to shoot the species in Eastern Europe, and Central and East Asia (M. Kessler in litt. 2016, Nagy 2018), despite the ban on hunting in all range countries (Nagy 2018, Kessler and Batbayar 2023). In some countries (e.g., Russia) hunting is organised and advertised online (Nagy 2018). Illegal killing therefore remains a critical threat in these regions, with the exception of Iran and Xinjiang, China (Kessler 2022, Özgencil et al. 2022), and especially where larger wintering flocks occur, as their killing can heavily impact the small breeding populations from which they originate (Kessler 2022). The species is also vulnerable to the indiscriminate poisoning of wild birds for food trade in China (M. Kessler in litt. 2016, Kessler and Batbayar 2023), and egg collecting in Iran (Naderi 2017 per Kessler and Batbayar 2023). Disturbance from hunting or poaching in winter on or nearby the species' wintering grounds, as well as disturbance, mainly from cars and walkers in Spain cause negative impacts on the birds' fitness and abundance in those areas (Sastre et al. 2009, Nagy 2018).
Collision with powerlines and wind turbines are also a major threat to the species, and the highest cause of mortality in adults in Europe, and a threat which is likely to increase and expand over the species' range (J. C. Alonso in litt. 2007, 2016; Alonso et al. 2016a, Nagy 2009, M. Kessler in litt. 2012, S. Nagy in litt. 2012, Raab et al. 2012, Barrientos et al. 2012, Vadász and Lóránt 2015, Palacín et al. 2017, Alonso 2014 per Kessler and Batbayar 2023). The impacts of climate change may increasingly affect the species (Nagy 2009, Alonso et al. 2016b), with harsh winter weather causing adult mortality and heavier summer rainfall leading to loss of clutches (M. Kessler in litt. 2016, Nagy 2018), but also with increasing wildfires contributing significantly to habitat loss and potentially nest destruction, if occurring during the breeding season (Bold 2003, Malkov 2012 and Yi Y Liu et al. 2013 per Kessler and Batbayar 2023). Predation, particularly by domestic dogs Canis lupus domesticus, also plays a role in the species' decline (Kessler 2022, Kessler and Batbayar 2023), but the impact of other non-native predators is not clear (Nagy 2018). The predation, especially of eggs or chicks by native mammalian and avian predators (Nagy 2018) in unbalanced ecosystems can also limit the species' populations.
Conservation Actions Underway
CITES Appendix I and II, CMS Appendix I and II and CMS MoU for Middle-European Populations in place since 2002 (with the fifth Meeting of the Signatories taking place in September 2023 [CMS 2023]), as well as the CMS Action Plan for the Great Bustard in Asia to be formally adopted in 2024 (Kessler and Batbayar 2023, update from the action plan for east Asian populations [Chan and Goroshko 1998]). EU Wild Birds Directive Annex I, Bern Convention Annex II.
A European action plan was published in 1996 and updated in 2009 (Nagy 2009) and more recently adapted for the Middle-European Populations MoU (Nagy 2018). In addition, a 'Concerted Action' for the species was established among Asian range states in 2017 (Government of Mongolia et al. 2017 per Kessler and Batbayar 2023). An action plan for Morocco was produced in 2016 (IUCN and HCEFLCD 2016) and in Türkiye an action plan was published in 2004 (Doğa Derneği ve T.C. Çevre ve Orman Bakanlığı, Doğa Koruma ve Milli Parklar Genel Müdürlüğü 2004). Agri-environmental and land management programmes have been implemented in Spain, Portugal, Austria, Hungary, Germany, and Serbia.
Monitoring of populations occurs in many range countries, e.g. across the EU and Europe (BirdLife International 2021) and across Türkiye (M.M. Karataş in litt. 2016).
Hunting of the species is prohibited in all the range states of the Middle-European Populations MoU, and range states in Asia (Nagy 2018, Kessler and Batbayar 2023), as well as in the European Union and in Türkiye since 1977.
Artificial incubation and chick rearing projects have been established in Germany and Hungary since the 1970s. A UK reintroduction project began in 2003 with chicks and eggs imported from the Russian Federation and later eggs from Spain (Dawes 2008, Great Bustard Group 2023) that has established a small population, with first successful nesting and chicks fledging in 2009 (Burnside et al. 2012). A LIFE + project was established in 2010 (European Commission 2021), which continued the release and monitoring of the species, the selection of two new release sites, protection from threats, and establishing agro-environmental schemes and land management advice to farmers, as well as a long-term management strategy. Chicks ceased to be imported in 2022 (N. Collar in litt. 2023), but management is still needed in the form of removing and incubating eggs from nests in fields being harvested and releasing the hatched chicks once the harvest is over (Stubbs 2020, N. Collar in litt. 2023).
A LIFE Nature project for the species was implemented in Hungary during 2004-2008 with the aim of increasing in-situ protection of the species (Bankovics and Lóránt 2008). Other LIFE projects for the species have been implemented in Spain, Portugal, Germany, Austria and Slovakia (e.g. LIFE Great Bustard 2022). Indeed, continued and intensive conservation actions in the West Pannonian population (Germany, Austria, and Hungary) have led to significant increases in this population, as well as in Romania, due to the dispersal from this increasing West Pannonian population. Using powerline markers and using underground cables instead of over-head powerlines have been shown to reduce mortality in this species (Raab et al. 2012). Accurate distribution maps of the species (e.g. in Spain) is assisting the sensitive development of renewable energy infrastructure (Palacín et al. 2023).
75-105 cm. Large, grey-and-brown bustard. Grey head and neck, brown barred black above. White underparts with reddish-brown breast-band, developing with age in males. Males significantly larger than females and develop a gular pouch and long white whiskers during the breeding season. Upright stance and deliberate walk. In flight, powerful regular wing beats resemble an eagle, but does not glide. Voice Displaying males make hollow umb sound. Alarm call a short, nasal bark. Young birds have a soft, trilling call.
Text account compilers
Burfield, I., Rutherford, C.A., Martin, R.
Contributors
Alonso, J.C., Andryushchenko, Y., Antonchikov, A., Ararat, K., Ashpole, J, Ayé, R., Baccetti, N., Barati, A., Collar, N., Garrido, J., Goriup, P., Karataş, M., Kessler, M., Nagy, S., Perlman, Y., Raab, R., Sheldon, R., Symes, A. & Westrip, J.R.S.
Recommended citation
BirdLife International (2024) Species factsheet: Great Bustard Otis tarda. Downloaded from
https://datazone.birdlife.org/species/factsheet/great-bustard-otis-tarda on 23/11/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from
https://datazone.birdlife.org/species/search on 23/11/2024.