Oryx Vol 39 No 1 January 2005 Key issues in assessing the feasibility of reintroducing the great bustard Otis tarda to Britain Patrick E. Osborne Abstract The great bustard is a globally-threatened belonged to the central European group and that restock- species needing conservation action across Europe. This ing should not use birds from Iberia. Only Russia has paper discusses key issues in the case for reintroducing sufficient birds to supply a reintroduction project and the bird to Britain. Great bustards became extinct as a losses there through nest destruction are high. By rescu- breeding species in Britain in 1832 probably as a result of ing eggs, artificially incubating them and transporting hunting, agricultural change and inclement weather. The chicks to Britain, the project should have zero detriment factors that caused the loss are no longer thought to to the donor population. Modelling indicates that 40 operate. Suitable habitat exists in pockets across England chicks will need to be brought to Britain for 5–10 years and especially on Salisbury Plain where a large area is to build a founder population of 100 birds. Although protected for military training and conservation pur- focused on direct action in Britain, the project will poses. The Plain combines short grass areas for lekking, promote grassland conservation across Europe and serve long grassland for feeding and adjacent arable land for nesting. Pilot studies on arthropods in long grassland as a model for translocating bustards elsewhere. suggest that their density is sufficient for chick-rearing but the precautionary creation of additional food-rich Keywords Britain, captive breeding, extinction, great areas among arable crops is recommended. Genetic bustard, Otis tarda, population viability, reintroduction, studies indicate that Britain’s bustards probably Russia, translocation. Introduction level. Internationally, Article 8(f) of the Convention on Biological Diversity requires Contracting Parties to reha- The great bustard Otis tarda is a globally-threatened bilitate and restore degraded ecosystems and promote species of steppe and pseudo-steppe habitats with a the recovery of threatened species through the develop- world population of 31,000–37,000 individuals (Heredia ment and implementation of plans or other management et al., 1996; BirdLife International, 2004). Its Red List category (IUCN, 2003) is Vulnerable based on criteria strategies. At European level, the EC Habitats Directive A2c, because a population reduction of more than 30% is 92/43/EEC obliges Member States to consider the predicted within the next 10 years (BirdLife Interna- feasibility of restoring species that have become locally tional, 2004). It is patchily distributed from Portugal, extinct. Nationally, the importance of biodiversity con- Spain and northern Africa, across central, southern and servation has been given statutory basis under Section eastern Europe, southern Siberia and Mongolia to parts 74 of the Countryside and Rights of Way Act 2000 that of eastern China (Morales & Martín, 2003). The species requires government departments to have regard for has declined since the turn of the 19th century due to biodiversity and to take positive steps to further the habitat loss, nest destruction, pesticide use, persecution conservation of listed species and habitats. Apart from through hunting, and collisions with power lines. A the great auk Pinguinus impennis (extinct since the 1840s) European Action Plan was adopted by the Council of and the migratory Kentish plover Charadrius alexandrinus Europe in 1996 (Heredia et al., 1996), and includes consid- (last nested in Lincolnshire in 1979), the great bustard is eration of reintroduction projects in Britain, France and the only bird species that bred regularly in Britain within Poland. The case for restoring species in Britain is the last 200 years but no longer does so. After a detailed enshrined in legislation from the international to national consultation phase on the case for reintroduction (Osborne, 2002), based on IUCN guidelines (IUCN, 1995), the British Government approved a licence in Patrick E. Osborne School of Biological and Environmental Sciences, November 2003 for a 10-year trial reintroduction of the University of Stirling, Stirling, FK9 4LA, UK. E-mail [email protected] great bustard to Britain. The first birds were brought Received 4 December 2003. Revision requested 2 June 2004. to Britain in August 2004 and 22 were released the Accepted 13 August 2004. following month. This paper summarizes the evidence 22 © 2005 FFI, Oryx, 39(1), 22–29 DOI: 10.1017/S0030605305000050 Printed in the United Kingdom Downloaded from https://www.cambridge.org/core. IP address: 170.106.33.42, on 01 Oct 2021 at 14:30:43, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/S0030605305000050 Reintroduction of great bustards to Britain 23 put forward to answer some of the most challenging unenclosed (Burton, 1995) and enclosure was by no issues in the guidelines. The underlying argument is that means uniform across the country; some areas, including a reintroduction attempt is feasible and the only way to large tracts of Salisbury Plain, were never enclosed. learn more about bustard ecology in Britain, which was Enclosure alone is therefore unlikely to have caused poorly documented prior to extinction. extinction. Stevenson (1870) thought that changes in agricultural practice brought about the extirpation of bustards in Issue 1. History and reason for extinction Norfolk. Before the decline, hen bustards frequently in Britain laid their eggs in winter-sown rye that had been hand- Bones from Gough’s Old Cave, dating from 9,300–12,300 broadcast. Wheat gradually replaced rye and its high BP, are the earliest evidence of the great bustard in value inspired the invention of the seed-drill, which Britain (Harrison, 1989) and there can be little doubt that minimized wastage and facilitated weeding, either by it is a native species. Written records begin with a house- parties of children or later by horse-hoeing. In the former hold account from the Borough of King’s Lynn (1371), case eggs were collected for incubation at home or for hunting regulation from Yorkshire (1512), recorded trophies, and in the latter nests were destroyed. He notes occurrence in Scotland (1526), and notes in household ‘thus, every nest made by a bustard in a wheat-field was books from Norfolk in 1527 and 1530 (Yarrell, 1882–4; sure to be discovered’ (Stevenson, 1870). The advent of Stevenson & Southwell, 1890). The species was appar- mechanical hoes also permitted inter-row cultivation, ently widespread in the 16th century and both the bird a practice unknown to medieval farmers (O’Connor & and its eggs were taken for food (Yarrell, 1882–4). Later, Shrubb, 1986), which left a smaller area of the land around 1670, Sir Thomas Browne described the bird as untilled and available for breeding birds. ‘not unfrequent’ in Norfolk and an advertisement from Hudson (1923) states that the great bustard was ‘delib- 1712 for an estate in Essex noted ‘all game in great plenty, erately extirpated’ and ‘pursued in that ruthless manner even to the bustard and pheasant’ (Yarrell, 1882–4). In that seems to indicate on the part of the persecutors a other areas the birds were by then scarce, Morton noted fixed relentless determination to wipe the species out’. in 1712 that he had never heard of more than two bus- Coward (in Hudson, 1923) adds ‘perhaps more than tards in Northamptonshire (in Yarrell, 1882–4). Evidence either [the spread of cultivation or increase in human for a decline in British bustards begins around the mid- population] improvement in sporting guns, swept them 1700s and they had become ‘exceedingly scarce in their away’. On taxidermy, Knight (1866) notes that ‘when the southern haunts’ by the end of the 18th century (Yarrell, mania for real British specimens of birds was prevalent, 1882–4). Although a statute was enacted in 1775 to the bustards suffered not a little. We know a collector prohibit spring and summer hunting (Collar, 1979), great who, about the year 1816, had nine dead bustards before bustards dwindled to extinction, the last breeding dates him together’. for Britain being 1830 for Norfolk and 1832 for Suffolk While these anthropogenic factors were affecting bus- (Morales & Martín, 2003). tards, Britain’s climate was also generally unfavourable. While the exact reason for the great bustard’s extinc- The period 1250–1850 saw deterioration in Europe’s tion is not known (Collar, 1979), the historical literature climate and the Little Ice Age of 1550–1700 brought suggests possible causes and facilitates judgement on the especially cold winters and cool springs, conditions that likelihood of similar events occurring today. There is no would almost certainly have increased winter mortality historical evidence of disease, pollution, poisoning, com- and reduced breeding. Significantly, great bustards petition or predation. Four other causes may have played became extinct as a breeding species in France, southern a part either alone or in concert: field enclosure, agricul- Sweden and northern Italy in the mid to late 1800s, tural mechanization, hunting for food and trophies, and shortly after their extinction in Britain (Isakov, 1974), climate change. suggesting that factors outside Britain were involved. In 1821 Graves wrote: ‘the enclosing and cultivating A key issue is whether these factors could still be [of] those extensive downs and heaths in various parts of operating in Britain today. Hunting is well regulated Great Britain, on which formerly this noble species was and the illegal killing of bustards is unlikely to pose a seen in large flocks, threatens within a few years to extir- serious threat. Agriculture, although highly mechanized, pate the bustard from this country’ (quoted in Thomas, employs far fewer people on the land to disturb nesting 2000). The enclosure of common land through Parlia- birds and destroy eggs.