Get access

Managed relocation as an adaptation strategy for mitigating climate change threats to the persistence of an endangered lizard

Authors

  • Damien A. Fordham,

    Corresponding author
    1. School of Earth and Environmental Sciences, University of Adelaide, Adelaide, South Australia, Australia
    • Correspondence: Damien A. Fordham, The Environment Institute, School of Earth and Environmental Sciences, The University of Adelaide, Adelaide 5005, Australia, tel. +61 8 8303 6711, fax +61 8 8303 4347, e-mail: damien.fordham@adelaide.edu.au

    Search for more papers by this author
  • Michael J. Watts,

    1. School of Earth and Environmental Sciences, University of Adelaide, Adelaide, South Australia, Australia
    Search for more papers by this author
  • Steven Delean,

    1. School of Earth and Environmental Sciences, University of Adelaide, Adelaide, South Australia, Australia
    Search for more papers by this author
  • Brook W. Brook,

    1. School of Earth and Environmental Sciences, University of Adelaide, Adelaide, South Australia, Australia
    Search for more papers by this author
  • Lee M.B. Heard,

    1. School of Earth and Environmental Sciences, University of Adelaide, Adelaide, South Australia, Australia
    2. Science Resource Centre, Department of Environment and Natural Resources, Adelaide, South Australia, Australia
    Search for more papers by this author
  • C.M. Bull

    1. School of Biological Sciences, Flinders University, Adelaide, Australia
    Search for more papers by this author

Abstract

The distributional ranges of many species are contracting with habitat conversion and climate change. For vertebrates, informed strategies for translocations are an essential option for decisions about their conservation management. The pygmy bluetongue lizard, Tiliqua adelaidensis, is an endangered reptile with a highly restricted distribution, known from only a small number of natural grassland fragments in South Australia. Land-use changes over the last century have converted perennial native grasslands into croplands, pastures and urban areas, causing substantial contraction of the species' range due to loss of essential habitat. Indeed, the species was thought to be extinct until its rediscovery in 1992. We develop coupled-models that link habitat suitability with stochastic demographic processes to estimate extinction risk and to explore the efficacy of potential climate adaptation options. These coupled-models offer improvements over simple bioclimatic envelope models for estimating the impacts of climate change on persistence probability. Applying this coupled-model approach to T. adelaidensis, we show that: (i) climate-driven changes will adversely impact the expected minimum abundance of populations and could cause extinction without management intervention, (ii) adding artificial burrows might enhance local population density, however, without targeted translocations this measure has a limited effect on extinction risk, (iii) managed relocations are critical for safeguarding lizard population persistence, as a sole or joint action and (iv) where to source and where to relocate animals in a program of translocations depends on the velocity, extent and nonlinearities in rates of climate-induced habitat change. These results underscore the need to consider managed relocations as part of any multifaceted plan to compensate the effects of habitat loss or shifting environmental conditions on species with low dispersal capacity. More broadly, we provide the first step towards a more comprehensive framework for integrating extinction risk, managed relocations and climate change information into range-wide conservation management.

Get access to the full text of this article

Ancillary