Impacts of survival and reproductive success on the long-term population viability of reintroduced great bustards Otis tarda in the UK

Kate Ashbrook, Andrew Taylor, Louise Jane, Ian Carter, Tamás Székely

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

Reintroductions aim to re-establish species within their historical ranges through the release of wild- or captive-bred individuals following extirpation (or extinction) in the wild. There is no general agreement on what constitutes a successful reintroduction but the probability of the population achieving long-term persistence should be addressed. Here we review a 10-year trial reintroduction of the great bustard Otis tarda, a globally threatened bird species, to the UK and assess the long-term population viability. Despite changes in rearing and release strategy, initial post-release survival probability remained consistently low, with only 11.3% of bustards (n = 167) surviving from release to 1 year post-release. Nineteen breeding attempts were made by eight females; however, only one chick survived > 100 days after hatching, and no wild juveniles have recruited into the population. Using demographic rates from the UK population and wild populations elsewhere, and stochastic population modelling, we investigate the viability of this reintroduced population by predicting population size over the next 10 years. Under current demographic rates the population was predicted to decline rapidly. Self-sufficiency was predicted only using the highest estimates from the UK population for first-year and adult survival, and recruitment rates from wild populations elsewhere. Although changes have been made in rearing, release strategies, habitat management and release sites used, these changes appear to have a modest effect on long-term viability. Substantial improvements in survival rates and productivity are necessary to establish a viable great bustard population in the UK, and we consider this unlikely.

LanguageEnglish
Pages583-592
Number of pages10
JournalOryx
Volume50
Issue number4
Early online date26 Jun 2015
DOIs
StatusPublished - Oct 2016

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reproductive success
reintroduction
viability
wild population
rearing
population modeling
habitat management
self sufficiency
hatching
population size
persistence
extinction
breeding
productivity
rate
Otis tarda
demographic statistics
Otididae
habitat conservation
threatened species

Keywords

  • Captive rearing
  • conservation
  • habitat management
  • monitoring
  • release strategy

Cite this

Impacts of survival and reproductive success on the long-term population viability of reintroduced great bustards Otis tarda in the UK. / Ashbrook, Kate; Taylor, Andrew; Jane, Louise; Carter, Ian; Székely, Tamás.

In: Oryx, Vol. 50, No. 4, 10.2016, p. 583-592.

Research output: Contribution to journalArticle

Ashbrook, Kate ; Taylor, Andrew ; Jane, Louise ; Carter, Ian ; Székely, Tamás. / Impacts of survival and reproductive success on the long-term population viability of reintroduced great bustards Otis tarda in the UK. In: Oryx. 2016 ; Vol. 50, No. 4. pp. 583-592.
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