There is contentious debate surrounding the merits of de-extinction as a biodiversity conservation tool. Here, we use extant analogues to predict conservation actions for potential de-extinction candidate species from New Zealand and the Australian state of New South Wales, and use a prioritization protocol to predict the impacts of reintroducing and maintaining populations of these species on conservation of extant threatened species. Even using the optimistic assumptions that resurrection of species is externally sponsored, and that actions for resurrected species can share costs with extant analogue species, public funding for conservation of resurrected species would lead to fewer extant species that could be conserved, suggesting net biodiversity loss. If full costs of establishment and maintenance for resurrected species populations were publicly funded, there could be substantial sacrifices in extant species conservation. If conservation of resurrected species populations could be fully externally sponsored, there could be benefits to extant threatened species. However, such benefits would be outweighed by opportunity costs, assuming such discretionary money could directly fund conservation of extant species. Potential sacrifices in conservation of extant species should be a crucial consideration in deciding whether to invest in de-extinction or focus our efforts on extant species.
Technological advances are reducing the barriers to resurrecting extinct species or their close genetic proxies, allowing de-extinction to be considered as a biodiversity conservation tool. Arguments in favour of de-extinction include necessity, driven by the rapid rate of species and habitat loss, an ethical duty to redress past mistakes, as well as potential technological and ecological knowledge that could stem from de-extinction programmes. Counter-arguments include high risk of failure due to difficulties of cloning for some species, technical risks inherent in re-introductions , loss of culture in resurrected animal species, and lack of remaining habitat for some species, as well as negative consequences for extant species, including reduced incentive for traditional conservation, and ecological impacts of introducing long-absent or genetically modified species.
The relative cost versus benefit for biodiversity is fundamental to the debate surrounding de-extinction. Assuming species are resurrected to be released into former habitats, the cost of de-extinction includes the process of producing initial founder populations, translocating individuals, then monitoring and managing new wild populations. If conservation funds are re-directed from extant to resurrected species, there is risk of perverse outcomes whereby net biodiversity might decrease as a result of de-extinction. Although private agencies might fund the resurrection of extinct species out of technical or philanthropic interest, the subsequent ongoing management of such species (many of which would face the same threats that made them extinct) would fall on government agencies, as commonly occurs with extant threatened species. Alternatively, if private agencies are willing to provide new funding for post de-extinction management, there could be additional benefits to species sharing habitats or threats.
Here, we test the potential impact of establishing and sustaining wild populations of resurrected extinct species (or proxies of such species) on the conservation of extant species. Specifically, we use long-term conservation programmes for extant analogue species in New Zealand (NZ) and the Australian state of New South Wales (NSW), to infer potential conservation actions for resurrected species, and predict the impact of resurrected species programmes on conservation of extant species. We use these datasets because they contain detailed prescriptions and costs of actions designed to achieve population recovery for most of the extant threatened species requiring specific management actions in either jurisdiction. We estimate the net number of extant species that can be conserved, using the following scenarios:
(1) establishment and maintenance of resurrected species become the burden of government conservation programmes, and
(2) establishment and maintenance of resurrected species populations are funded externally using non-public resources.
In Scenario 1, the use of government resources on resurrected species results in less funding for extant species programmes, but provides potential benefits for species that share actions with resurrected species. In Scenario 2, there are also potential benefits to extant species conservation programmes through shared conservation actions. However, there are potential opportunity costs, if private agencies use resources they could otherwise have used on conservation of extant species. Our analysis assumes that species would be resurrected to be re-introduced into their former habitats, rather than for other potential reasons, such as research or public display.