Metapopulation management of an Endangered species with limited genetic diversity in the presence of disease: the Tasmanian devil Sarcophilus harrisii

Abstract

There has been much discussion relating to the current biodiversity crisis, with the loss of species now at an unprecedented rate. Using augmentation and/or reintroduction to minimize the loss of species in the wild is becoming more prominent. Zoological institutions have been traditionally involved in the management of insurance populations providing a range of species for release to the wild. Insurance populations can be costly, both in resources and behavioural changes, and so should aim to be maintained for as short a time as possible, with a maximum of 40 years. A Tasmanian devil Sarcophilus harrisii insurance population was established in 2006 with the arrival of devil facial tumour disease, and was founded with 120 individuals sourced predominantly from the west coast of Tasmania. Here the challenges of establishing and managing an insurance population in an already genetically depauperate species in the presence of a contagious cancer are discussed. The Tasmanian devil insurance metapopulation now includes a continuum of management scenarios (from intensive zoo-based facilities, through free-range enclosures, to an island and fenced peninsula) and consists of over 700 devils representing at least 180 founders. The lessons learned in regard to this programme are presented, including the issues surrounding reduced genetic diversity and how we are striving to improve the long-term management of the insurance metapopulation through a combination of molecular genetics, modelling and on-the-ground management. The tools and technologies that have been developed in this programme are directly applicable to the recovery and management of a suite of other threatened fauna.