VU
Great Bustard Otis tarda



Justification

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, as well as hunting. Some populations in its Iberian stronghold have been suggested to have stabilised and possibly increased, although there is now some evidence for at least local declines in some areas in this region. Additionally, hunting in Central and East Asia results in high rates of adult mortality, and land-use changes in eastern Europe, Russia, Central Asia and Morocco may have a significant impact on this species's population and the extent of its remaining habitat, such that it is likely to decline at a rapid rate over the next three generations. It therefore qualifies as Vulnerable. Should research show the species to be declining at a more moderate rate, it would warrant downlisting to a lower category of threat.

Population justification
Alonso (2014) estimates the global population to number 43,847 – 56,695 individuals, rounded here to 44,000-57,000 individuals.

Trend justification
The species is suspected to have historically undergone a rapid population decline, owing to habitat loss and fragmentation for agricultural intensification, as well as hunting and collision with power lines. There is a lack of accurate data on current trends in several countries with important populations (e.g. parts of Russia, Mongolia, China), although declines have continued in some range states especially in eastern and central Europe, Morocco, as well as throughout the eastern part of the global distribution (Chan and Goroshko 1998, Barati and Amerifar 2008, Palacín and Alonso 2008, Oparin et al. 2013, BirdLife International 2015, Alonso et al. 2016b, M. Karataş in litt. 2016). In other areas (notably Hungary, Germany, Austria and the Iberian Peninsula) the population has been increasing or potentially stable since the 1990s (see Nagy 2009, Martín et al. 2012, BirdLife International 2015, J. Garrido in litt. 2017). Therefore, declines in the recent past are not thought to be significant (see Alonso 2014, Palacín and Alonso 2008, Alonso and Palacín 2010). However, the population in the Iberian Peninsula may now (at least in some local areas) be starting to decline or have very low productivity (J. C. Alonso in litt. 2017, Y. Perlman in litt. 2017). With continued agricultural expansion and climate change likely to impact the species even more into the future, the species is precautionarily considered to be undergoing a moderately rapid decline over a 3 generation period (30 years), which will continue or potentially increase into the future. Should research show the species to be declining at a more moderate rate, it would warrant downlisting to a lower category of threat.

Distribution and population

This species breeds in Morocco (45-50 birds [IUCN and HCEFLCD 2016, Alonso et al. 2016a]), Portugal (1,893 birds [per Alonso 2014]), Spain (29,400-34,300 birds [per Alonso 2014] although it could be lower than this [Y. Perlman in litt. 2017]), Austria (211-407 birds [R. Raab per J. C. Alonso in litt. 2016]), Germany (197 birds [Staatliche Vogelschutzwarte Brandenburg & Förderverein Grosstrappenschutz and T. Langgemach per J. C. Alonso in litt. 2016]), Slovakia (0-3 birds [per Alonso 2014]), Hungary (1,547 birds L. Miklós per J. C. Alonso in litt. 2016), Serbia and Montenegro (35-36 birds [per Alonso 2014]), Romania (0-8 birds [per Alonso 2014]), Turkey (700-1180 individuals [M. M. Karata? in litt. 2016]), Iran (43-48 birds [Barati et al. 2015]), Russia (8,000-12,000 birds in European Russia [per Alonso 2014], 500 individuals of the Asian subspecies in Eastern Russia [M. Kessler in litt. 2016]), Ukraine (520-680 birds [per Alonso 2014]), Kazakhstan (0-50 birds [per Alonso 2014]), Mongolia (c.1,000 birds [Palacín and Alonso 2008]), and China (c.500-3,300 birds [Chan and Goroshko 1998, Alonso and Palacín 2010, M. Kessler in litt. 2012]); and a reintroduction scheme is currently taking place in the United Kingdom. Its Palearctic range is becoming increasingly disjunct and there have been rapid declines and some extinctions throughout eastern and central Europe (Bulgaria, Poland, Moldova [Palacín and Alonso 2008], Czech Republic [BirdLife International 2015]). Numbers have almost certainly declined in Czech Republic, Slovakia, Romania, Bulgaria, Poland, Moldova, Kazakhstan, Mongolia, Turkey and Morocco, and in most of the eastern distribution range (Chan and Goroshko 1998, Barati and Amerifar 2008, Palacín and Alonso 2008, Alonso et al. 2016a, Palacín et al. 2016, M. M. Karata? in litt. 2016), along a with a range contraction due to the disappearance of smaller populations across the species's range (e.g. in Iberia [Alonso et al. 2003, Alonso et al. 2004] and Hungary [Faragó 1993]). The species is now absent from much of its range in Iran, with West Azarbayjan the only region where conditions remain suitable for the species (Barati et al. 2015). Over the past half century the species has only rarely been sighted in Kyrgyzstan, Tajikistan and Azerbaijan where the species once bred (M. Kessler in litt. 2016). In contrast, the species has increased in Hungary, Austria, and Germany, Spain and Portugal (Alonso and Palacín 2010, BirdLife International 2015). The previous fluctuating trend in Russia has changed to a rapid decrease during recent years (Antonchikov 2008, 2011) with a decrease of 68-70% estimated for the period 1999-2011 (BirdLife International 2015). Only a small number of birds (~40) continue to breed in the Russian Caucasus and the species is listed locally as Extinct or Critically Endangered in most of the Russian steppe zone (Kessler 2016, M. Kessler in litt. 2016). Recent trends are unknown in some parts of Asia. The world population is estimated to be between 43,847 and 56,695 individuals (Alonso 2014), of which 57-70% occur in Spain and 15-25% along the lower Volga River (Alonso and Palacín 2010, Kessler 2014). Only c.1,200-2,000 (c.4% of the global population) of the eastern subspecies remain in east Asia (Kessler 2014).

Most populations of the western subspecies are partially migratory and 8,000-10,000 birds occur on passage or in winter in Ukraine arriving from the lower Volga River, though only c.4,100 were found in 2010 (Y. Andryushchenko in litt. 1999, 2017, M. Kessler in litt. 2016). In the past birds from northern Central Asia overwintered in large numbers in Turkmenistan and Azerbaijan, as well as Uzbekistan, and north-east Iran, sightings are now rare in these countries (Kessler and Smith 2014). The eastern subspecies breeds in Mongolia, eastern Russia, and north-east China is fully migratory, spending four months on migratory stopovers and four months on wintering grounds in central China (Kessler et al. 2013, M. Kessler in litt. 2016). 

Ecology

Originally a species of the Eurasian steppe, this species has acclimated to agricultural landscapes (M. Kessler in litt. 2016). It occurs in open, flat or somewhat rolling landscapes, usually with a mixture of crops (cereals, vineyards, fodder plants, in some countries also with steppic grassland [J. C. Alonso in litt. 2012]). The eastern subspecies inhabits both open steppe and forest steppe, including small forest openings (M. Kessler in litt. 2016). 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 in agricultural mosaics, open steppe, and adjacent to forest edge (Kessler 2015). It exhibits highly variable migratory behaviour across populations, including obligate winter migrants (Asia, Russia), 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, 2001, Palacín et al. 2009, 2011).

Threats

Key threats are increased habitat degradation, fragmentation and loss due to agricultural intensification, land-use changes and infrastructure development which has 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 and fragmentation continues as a result of ploughing of grasslands, intensive grazing, afforestation and increasing development of irrigation schemes, roads, power-lines, fencing and ditches. Mechanisation (ploughing and harvesting in particular), chemical fertilisers and pesticides, fire and predation all contribute to high mortality in eggs, chicks, juveniles and incubating females (Nagy 2009, Rocha et al. 2013). The expansion of road networks can also degrade the species's habitat as well as create disturbance for the species (see Torres et al. 2011, Raab et al. 2014). Hunting is a major threat in Morocco, Syria, Turkey, Ukraine, China, Kazakhstan, Uzbekistan and Mongolia (Y. Andryushchenko in litt. 1999, Chan and Goroshko 1998, P. Goriup in litt. 2007, Karaka? and Akarsu 2009, M. Kessler in litt. 2012, 2016, M. M. Karata?  in litt. 2016) and is expected to intensify as the paved road network in Mongolia expands. International tourists are known to hunt the species in East Asia (M. Kessler in litt. 2016). The species is also vulnerable to the indiscriminate poisoning of wild birds for trade in China (M. Kessler in litt. 2016). Collision with power lines are a major threat to the species (J. C. Alonso in litt. 2007, 2016, Nagy 2009, M. Kessler in litt. 2012) and wind turbines may also be a significant threat (S. Nagy in litt. 2012). The impacts of climate change may increasingly affect the species (see Nagy 2009, Alonso et al. 2016), with harsh winter weather causing adult mortality and heavier summer rainfall leading to loss of clutches (M. Kessler in litt. 2016). 

Conservation actions

Conservation Actions Underway
CITES Appendix I and II, CMS Appendix I and II and CMS MoU for Middle European Populations in place since 2002. EU Wild Birds Directive Annex I, Bern Convention Annex II, Bonn Convention Annex I (S. Nagy in litt. 1999, 2007, P. Goriup in litt. 2007). A European action plan was published in 1996 and updated in 2009 (Nagy 2009) and an action plan for east Asian populations in 1998 (Chan and Goroshko 1998). An Action Plan for Morocco was produced in 2016 (IUCN and HCEFLCD 2016). Agri-environmental and land management programmes have been (successfully) implemented in Spain, Portugal, Austria, Hungary, Germany, Serbia. Hunting of the species has been prohibited by the Central Hunting Commission in Turkey since 1977, an action plan was published in 2004 (Do?a Derne?i ve T.C. Çevre ve Orman Bakanl???, Do?a Koruma ve Milli Parklar Genel Müdürlü?ü 2004) and survey counts have been successfully carried out across the country (M. M. Karata? in litt. 2016). 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 imported from the Russian Federation and later Spain (Dawes 2008) that has established a small population, although continued monitoring and supplementing is still needed (Burnside et al. 2012). 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. Using power line markers and using underground cables instead of over-head powerlines have been shown to reduce mortality in this species (Raab et al. 2012).

Conservation Actions Proposed
Coordinate conservation actions between range states in Asia, where the species is fully migratory (M. Kessler in litt. 2016). Conduct nationwide surveys in countries with currently low quality estimates, to confirm worldwide numbers and trends. Research limiting factors, and investigate its vulnerability to climate change, metapopulation dynamics and the causes of reproductive failure in East Asia (M. Kessler in litt. 2016). Research wintering distribution in Russia, Ukraine and Asia. Protect and manage breeding, wintering and stop-over areas. Identify remaining breeding sites in Central and East Asia, as well as upgrade existing and establish new protected areas in this region (M. Kessler in litt. 2016). Establish protected areas and strict conservation measures in Morocco, the only African population of the species (J. C. Alonso in litt. 2016). Implement agri-environment measures for low-intensity farming. Prevent steppe fires, stubble burning, illegal hunting and collision with power-lines. Re-route or bury overhead cabling at areas in which Great Bustards gather (M. Kessler in litt. 2016). Raise public awareness. Research wintering movements in eastern and south-eastern Anatolia (M. M. Karata? in litt. 2016).

Identification

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.

Acknowledgements

Text account compilers
Harding, M., Capper, D., Symes, A., Peet, N., Benstead, P., Ashpole, J, Westrip, J., Derhé, M.

Contributors
Garrido, J., Andryushchenko, Y., Raab, R., Alonso, J. C., Goriup, P., Ayé, R., Perlman, Y., Antonchikov, A., Collar, N., Barati, A., Nagy, S., Kessler, M., Karata?, M.


Recommended citation
BirdLife International (2023) Species factsheet: Otis tarda. Downloaded from http://datazone.birdlife.org/species/factsheet/great-bustard-otis-tarda on 02/12/2023.
Recommended citation for factsheets for more than one species: BirdLife International (2023) IUCN Red List for birds. Downloaded from http://datazone.birdlife.org on 02/12/2023.