By Dr John Kanowski, Chief Science Officer
Australia holds the world record for mammal extinctions in the modern era, losing close to 40 species in the last 200 years, driven primarily by predation by feral cats and foxes. A further 70 or so Australian mammal species are considered ‘extremely’ or ‘highly’ vulnerable to cats and foxes; most have suffered extensive declines. These extinctions and declines represent the loss of our natural heritage, the loss of cultural heritage for Indigenous people, and the disruption of important ecological processes – for example, the dispersal of seeds and fungal spores, and ‘soil engineering’ – across much of Australia.
Australian Wildlife Conservancy (AWC) is a national leader in the reintroduction of threatened mammals to parts of their former ranges. AWC’s reintroduction program is mostly built around the establishment of ‘safe havens’: fenced areas or islands from which cats and foxes have been eliminated. As of 2023, AWC manages ten safe havens, to which a total of 16 mammal species have been reintroduced; with another three mammal species reintroduced to two sites where predators are intensively controlled, but not eliminated.
These reintroductions, and those conducted by other conservation organisations and state government agencies, have made a major contribution to the recovery of threatened mammals in Australia. A recent paper by Professor John Woinarski and colleagues found that reintroductions to safe havens and/or intensive predator control had turned the tide of extinction for 11 Australian mammal species, nine of which are currently protected by AWC. This important work continues, with AWC planning to add another three threatened mammals to the safe haven network in 2023: the Northern Bettong (Bettongia tropica, listed as endangered); the Plains Mouse (Pseudomys australis, listed as vulnerable); and the Golden Bandicoot (Isoodon auratus, listed as vulnerable). AWC is also following up our 2022 translocation of the critically endangered Central Rock-rat (Zyzomys pedunculatus) to Newhaven, with a supplementary release of animals raised in the breeding program at Alice Springs Desert Park. Reintroductions can also help maintain or increase genetic diversity and adaptive capacity in threatened species, which is important for their long-term persistence.
Studies have shown that reintroduced populations established from two or more island populations (each of which has lost some genetic diversity) can become more genetically diverse than those remnant populations. Further, reintroductions can ensure that species are exposed to a broader range of environmental conditions than those experienced in remaining habitats. For example, a number of threatened mammals that once occurred across vast areas of inland Australia – such as the Woylie (Brush-tailed Bettong, Bettongia penicillata), Numbat (Myrmecobius fasciatus), Red-tailed Phascogale (Phascogale calura) and Chuditch (Western Quoll, Dasyurus geoffroii) – have contracted to south-west Western Australia, a moderately well-watered and climatically stable bioregion. AWC has reintroduced these species to one or more locations in semi-arid parts of their former ranges, re-establishing selection for genetic traits that facilitate persistence in these harsher, drought-prone environments.
AWC’s ambitious reintroduction program is part of a growing global movement, sometimes called ‘rewilding’, whereby conservationists are returning species to ecosystems from which they’ve become extinct due to hunting, habitat loss or degradation, or other pressures. In 2022, AWC was invited to present at the First Global Meeting of Conservation Translocation Practitioners, in Spain, alongside conservation organisations working in Europe, Africa, Mauritius, India, Argentina, and the USA, with iconic species such as tigers, jaguars, lynx, rhinos, and raptors. As AWC’s Chief Science Officer, I was fortunate to present on the Australian context to the meeting, drawing on AWC’s experience, with input from other Australian practitioners including Dr Kath Tuft from Arid Recovery; Associate Professor Katherine Moseby and Dr John Read from Mallee Refuge; Peter Copley from South Australian Department of Environment and Water; and Professor Adrian Manning from ANU/Mulligans Flat. I came away from the meeting with the following observations:
1. The practice of conservation translocations, or ‘rewilding’, is a global movement of substantial conservation and social importance.
2. AWC’s work fits right in – our program, appropriate in the Australian context, has strong conceptual links with the broader movement.
3. We share many aspects of our conservation model with other programs.
4. 80% of the ‘take-home-messages’ were similar across all continents/projects:
– translocations have major conservation value – many species have been and are being saved from extinction, and ecosystems are being restored;
– reintroductions have a positive social value to local communities and the broader society;
– there appears to be a common set of organisational values amongst conservation translocation practitioners, including vision, commitment, ‘getting stuff done’, agility and pragmatism; and
– risk-aversion by authorities was identified as a major constraint across many projects.
5. Of course, some issues aren’t shared – in Australia, fortunately, we don’t have to protect our staff against poachers, our translocated species don’t usually eat people or raid crops, and we can use a Cessna, rather than a Boeing 747, to translocate species across the continent.
Following on from this meeting and related work, AWC has been looking to strengthen cooperation with a number of our international counterpart organisations, with a view to mutual development. One of the first initiatives that may emerge from this network is a training program for future conservation leaders, drawing on the lessons of AWC and other contributing parties – more to come.
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