a1 University of Bath, Department of Biology and Biochemistry, Bath, BA2 7AY, UK.
a2 Natural England, Peterborough, UK
a3 Great Bustard Group, Winterbourne Gunner, Salisbury, UK
a4 Royal Society for the Protection of Birds, Sandy, UK
a5 Fieldfare International Ecological Development, Newbury, UK
The great bustard Otis tarda became extinct in the UK during the 19th century due to a combination of factors, including hunting, egg collection and changes in agriculture. In 2003 a 10-year licence was granted to begin a trial to reintroduce the species back to the UK. Here we report on the first 5 years of the trial and assess the progress made towards establishing a founder population. From April 2004 to September 2009 a total of 102 great bustard chicks were imported from Russia and 86 released on Salisbury Plain. Monitoring showed that post-release survival was 18% in the first year following release, and that mortality of released bustards was mainly attributable to predation and collisions. Estimated adult survival was 74%, although the sample size was small. All known surviving great bustards are faithful to the surroundings of the release site, returning throughout the year. A lek has been established where males have been observed displaying to females. The first nesting attempt was in 2007, and in 2009 two females aged 3 and 4 years successfully nested, fledging one chick each. Models incorporating the new demographic estimates suggest that at the end of the 10-year trial period the project can expect to have 8–26 adults as a founder population.
(Received December 10 2010)
(Reviewed February 01 2011)
(Accepted March 09 2011)
(Online publication November 24 2011)