1 Spending limited resources on de-extinction could lead to net biodiversity loss 2 Joseph R. Bennett1, Richard F. Maloney2, Tammy E. Steeves3, James Brazill-Boast4, Hugh P. 3 Possingham5,6, Phillip J. Seddon7 4 1. Department of Biology 5 Carleton University 6 1125 Colonel By Dr 7 Ottawa, ON K1S 5B6 8 Canada 9 [email protected] 10 ph: 613-520-2600 x 3124 11 fax: 613-520-3539 12 13 2. Science and Policy Group 14 Department of Conservation 15 70 Moorhouse Ave 16 Addington 17 Christchurch 8011 18 New Zealand 19 20 3. School of Biological Sciences 21 University of Canterbury 22 Private Bag 4800 23 Christchurch 8140 24 New Zealand 25 26 4. NSW Office of Environment and Heritage 27 59 Goulburn St 28 Sydney, Australia 29 30 5. University of Queensland 31 ARC Centre of Excellence for Environmental Decisions 32 School of Biological Sciences 33 St Lucia, QLD, Australia 34 35 6. Conservation Science 36 The Nature Conservancy 37 245 Riverside Drive 38 West End, QLD 4101 39 Australia 40 41 7. University of Otago 42 Department of Zoology 43 340 Great King Street 44 Dunedin 9016 45 New Zealand 46 1 47 There is contentious debate surrounding the merits of de-extinction as a biodiversity 48 conservation tool. Here, we use extant analogues to predict conservation actions for 49 potential de-extinction candidate species from New Zealand and New South Wales, and 50 use a prioritization protocol to predict the impacts of reintroducing and maintaining 51 populations of these species on conservation of extant threatened species. Even using the 52 optimistic assumptions that resurrection of species is externally sponsored, and that 53 actions for resurrected species can share costs with extant analogue species, public 54 funding for conservation of resurrected species would lead to fewer extant species that 55 could be conserved, suggesting net biodiversity loss. If full costs of establishment and 56 maintenance for resurrected species populations were publicly funded, there could be 57 substantial sacrifices in extant species conservation. If conservation of resurrected 58 species populations could be fully externally sponsored, there could be benefits to extant 59 threatened species. However, such benefits would be outweighed by opportunity costs, 60 assuming such discretionary money could directly fund conservation of extant species. 61 Potential sacrifices in conservation of extant species should be a crucial consideration in 62 deciding whether to invest in de-extinction or focus our efforts on extant species. 63 Technological advances are reducing the barriers to resurrecting extinct species or their close 64 genetic proxies, allowing de-extinction to be considered as a biodiversity conservation tool1,2. 65 Arguments in favour of de-extinction include necessity, driven by the rapid rate of species 66 and habitat loss3,4, an ethical duty to redress past mistakes5, as well as potential technological 67 and ecological knowledge that could stem from de-extinction programs4. Counter-arguments 68 include high risk of failure due to difficulties of cloning for some species6, technical risks 69 inherent in re-introductions7,8,9, loss of culture in resurrected animal species8, and lack of 70 remaining habitat for some species10,11, as well as negative consequences for extant species 2 71 including reduced incentive for traditional conservation12, and ecological impacts of 72 introducing long-absent or genetically-modified species12. 73 The relative cost versus benefit for biodiversity is fundamental to the debate surrounding de- 74 extinction. Assuming species are resurrected to be released into former habitats, the cost of 75 de-extinction includes the process of producing initial founder populations, translocating 76 individuals, then monitoring and managing new wild populations. If conservation funds are 77 re-directed from extant to resurrected species, there is risk of perverse outcomes whereby net 78 biodiversity might decrease as a result of de-extinction12,13. Although private agencies might 79 fund the resurrection of extinct species out of technical or philanthropic interest, the 80 subsequent ongoing management of such species (many of which would face the same threats 81 that made them extinct) would fall upon government agencies as commonly occurs with 82 extant threatened species. Alternatively, if private agencies are willing to provide new 83 funding for post de-extinction management, there could be additional benefits to species 84 sharing habitats or threats. 85 Here, we test the potential impact of establishing and sustaining wild populations of 86 resurrected extinct species (or proxies of such species) on the conservation of extant species. 87 Specifically, we use long-term conservation programs for extant analogue species in New 88 Zealand (NZ) and the Australian state of New South Wales (NSW), to infer potential 89 conservation actions for resurrected species, and predict the impact of resurrected species 90 programs on conservation of extant species. We use these datasets because they contain 91 detailed prescriptions and costs of actions designed to achieve population recovery for most 92 of the extant threatened species requiring specific management actions in either jurisdiction. 93 We estimate the net number of extant species that can be conserved, using the following 94 scenarios: 1) resurrected species become the burden of government conservation programs; 95 and 2) establishment and maintenance of resurrected species populations are funded 3 96 externally using non-public resources. In Scenario 1 the use of government resources on 97 resurrected species results in less funding for extant species programs, but provides potential 98 benefits for species that share actions with resurrected species. In Scenario 2 there are also 99 potential benefits to extant species conservation programs through shared conservation 100 actions. However, there are potential opportunity costs, if private agencies use resources they 101 could otherwise have used on conservation of extant species. Our analysis assumes that 102 species would be resurrected to be re-introduced into their former habitats, rather than for 103 other potential reasons such as research or public display. 104 Because little is known about the costs of producing viable initial populations of resurrected 105 species, we do not consider this in our analysis, and assume it is covered by a private agency. 106 Instead, we focus on the long-term cost of conservation for resurrected species, assuming that 107 such species would have small founder populations that require conservation actions similar 108 to those required for extant threatened species. 109 Although there is considerable uncertainty regarding necessary conservation actions for many 110 extinct species should they be resurrected7, we assume that such species would share many 111 actions with closely related extant species that share habitats, threats, and ecological roles. 112 We therefore chose focal extinct species from among the endemic, fully extinct species from 113 our study areas, based on similarity in taxonomy, range, habitat, life history, and threats with 114 an extant threatened analogue species. Among 70 recently extinct (1000 AD to present) 115 species in NZ, we found 11 for which we could assign reasonable analogues (Supplementary 116 Information Table 1). For NSW, we considered 29 recently extinct species, and found 5 with 117 reasonable extant analogues. Our inferred conservation programs for the extinct species 118 (assuming they were resurrected), were the same as for their analogue extant species, with the 119 addition of captive breeding and translocation costs, based on average costs of captive 120 breeding and translocation from extant species of the same taxonomic group (e.g. bird, 4 121 amphibian). Although cost and shared actions were not criteria for choosing our focal 122 species, our chosen group represented a broad range of estimated costs and number of extant 123 species with shared actions (Supplementary Information Table 1). We note that using 124 analogues in this way likely underestimates both cost and risk of failure, and that we assume 125 actions could be completely shared between resurrected and extant analogue species. It is 126 somewhat unlikely that an effective conservation program for a resurrected species would 127 completely share actions with that of an extant species. We also note that our analysis makes 128 the largely untested assumption that technical barriers to creating initial populations of these 129 species can be overcome6,14. Thus, our results should be regarded as being optimistic in 130 favour of net benefits of resurrected species conservation programs. 131 To assess the potential influence of resurrected species on extant species conservation, we 132 incorporated the proposed programs for resurrected species into threatened species project 133 prioritization protocols developed for the New Zealand Department of Conservation (NZ 134 DOC) and NSW Office of Environment and Heritage (see Methods for details). Costs of 135 shared actions (e.g. predator control that benefits several species sharing a site) were shared 136 among prioritized species recovery projects. Thus, if private funding covers the cost of 137 actions for a resurrected species, the cost of the same actions for any other species (including 138 the resurrected species’ analogue) would also be covered, potentially allowing more species 139 to be conserved within a given budget.