6 January 2026

There is a growing interest in releases of amphibians and reptiles into the wild (translocations), aimed at re-establishing nationally extinct species or introducing non-native species.

ARC has long been a champion of reintroducing native amphibian and reptile species, and has used this as a powerful tool to transform their prospects in Britain, through carefully planned conservation translocations. You can read here about our work in this field, and our guidance on releases. We will continue to expand our long-running reintroduction programmes, which have resulted in substantial gains for threatened species. We consider that reintroductions should look at both species recovery and ecosystem functionality, and the role of the reintroduced species in restored landscapes.

It is valuable to explore the potential for re-establishing species that went extinct a long time ago, though due to the changes over that time the prospects of return will require more thorough investigation compared to species that went extinct more recently, over the last century or so. Successful reintroductions include planning for the long term, and need substantial commitment into the future, well beyond the actual release itself. Any introduction of a new species will have consequences for local and national stakeholders, and these effects need exploring before approval of any release. As such, any proposals for releases should have the benefit of scrutiny by peers, use an evidence-based approach and follow established guidance.

We think introducing species outside of their known range, including those currently recognised as non-native to Britain, could also potentially be justified under particular circumstances. For example, if a species were threatened in its native range and the only realistic prospect to ensure its survival were to create new populations elsewhere. This process is known as assisted colonisation. We believe that serious pressures such as epidemic disease and climate change require innovative interventions, and that assisted colonisation is one potential option. That said, releasing non-native species often causes negative impacts on the receiving community, so undertaking assisted colonisation poses a dilemma. ARC has pioneered exploration of this complex issue for reptiles and amphibians in Britain, for example via a workshop at our annual conference in 2021. Assisted colonisation across international boundaries would require a significant shift in conservation policy, notably how non-native species are treated. It would need to be underpinned by clear criteria, apply across wildlife groups, and take an international perspective. We understand that Government and its agencies are currently working on guidance on this topic. Our assessment (as at December 2025) is that there are currently no amphibian or reptile species for which there is an unambiguous case meeting emerging criteria for this approach. However, we believe that the matter should be kept under active review, taking account of emerging policy, guidance and evidence.

Juvenile common tree frog (Hyla arborea). This spectacular frog is not generally considered native to Britain. Photo: Jim Foster/ARC.

 

Substantial work is needed to help our native species to recover, largely creating and restoring habitats, and many organisations offer opportunities for all in society to engage. It is important that any releases of any species should not detract from or undermine efforts to recover the reptiles and amphibians we currently have. Indeed, improving the conditions for those species already here could make it more feasible to introduce other species in future, should that become necessary.

Species for which we have heard suggestions for new releases include: moor frog Rana arvalis, agile frog Rana dalmatina, European tree frog Hyla arborea, midwife toad Alytes obstetricans, fire salamander Salamandra salamandra, Aesculapian snake Zamenis longissimus, common wall lizard Podarcis muralis, ocellated lizard Timon lepidus, and European pond terrapin/turtle Emys orbicularis. Some of these occurred as native species in Britain since the last ice age, whilst most are non-native. Recognising the risks posed by non-native species, legislation prohibits their release to the wild, either deliberately or by allowing them to escape from captivity, unless done under licence. Unlicensed releases into gardens and enclosed areas may also constitute an offence, since they may effectively be releases into the wild.

We recognise and applaud the interest in doing more to recover our beleaguered wildlife, here in the UK and overseas. Careful planning with evidence that supports the proposed approach are needed to be sure about the conservation benefits of any planned releases. Releases can present risks to our existing wildlife, for example through diseases, predation and competition, and studies confirm that even well-intentioned releases can lead to serious impacts on native species. Releases may also detract from ongoing efforts, or give unwarranted hope that simply releasing animals is an easy solution to the biodiversity crisis. Releases of native species may also require licensing or other permissions, depending on the circumstances. We strongly support releases where there is a robust conservation case for reintroduction, the benefits outweigh the risks, and the project complies with good practice and legislation. These include, amongst other things, consideration of the origin of the animals being released, the locations and habitats in which they are released, and the measures to manage the impacts they might have.

We are keen to see robust and restored reptile and amphibian populations playing a key role in ecosystems, and valued by society. Conservation translocations will have a continuing role to play in achieving this aim, which will require responsible planning, delivery and evaluation.

We will expand our guidance on these issues in the coming months, and we welcome any constructive feedback (please email to [email protected]).

Further reading

Brodie, J. F., Lieberman, S., Moehrenschlager, A., Redford, K. H., Rodríguez, J. P., Schwartz, M., Seddon P. J., & Watson, J. E. (2021). Global policy for assisted colonization of species. Science, 372(6541), 456-458.

D'Andrea, R., Barabás, G., Dalrymple, S. E., Foden, W., Genovesi, P., Krishnadas, M., Leibold, M.A., McPeek, M.A., Moehrenschlager, A., Rodriguez, J.P. & Akçakaya, H.R. (2025). Ecological Risk–Benefit Analysis for Assisted Colonization. Global Change Biology, 31(11), e70613.

Defra (2024). Reintroductions and other conservation translocations: code and guidance for England. May 2021. Version: 1.2 (updated July 2024). Defra, London.

Foster, J. (2022). Does climate change herald a new herpetofauna for the UK? Views held by attendees at a conservation conference in 2021. Unpublished report. Amphibian and Reptile Conservation Trust, Bournemouth. URL: https://www.arc-trust.org/Handlers/Download.ashx?IDMF=93ef597a-206c-40d5-ab9f-1c45383b8342

Gardner, C. J., and Bullock, J. M. (2025). Revisiting the Case for Assisted Colonisation Under Rapid Climate Change. Journal of Applied Ecology 62: 1071–1077.

IPBES (2023). Summary for Policymakers of the Thematic Assessment Report on Invasive Alien Species and their Control of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services. Roy, H. E., Pauchard, A., Stoett, P., Renard Truong, T., Bacher, S., Galil, B. S., Hulme, P. E., Ikeda, T., Sankaran, K. V., McGeoch, M. A., Meyerson, L. A., Nuñez, M. A., Ordonez, A., Rahlao, S. J., Schwindt, E., Seebens, H., Sheppard, A. W., & Vandvik, V. (eds.). IPBES secretariat, Bonn, Germany.

IUCN SSC (2013). Guidelines for Reintroductions and Other Conservation Translocations. Version 1.0. IUCN Species Survival Commission. IUCN, Gland, Switzerland.

Pouget, D. and Sabel, J. (2025). Using species conservation translocations as a tool for nature recovery. Natural England blog. URL: https://naturalengland.blog.gov.uk/2025/03/26/using-species-conservation-translocations-as-a-tool-for-nature-recovery/

Pyšek, P., Hulme, P. E., Simberloff, D., Bacher, S., Blackburn, T. M., Carlton, J. T., Dawson, W., Essl, F., Foxcroft, L. C., Genovesi, P. & Jeschke, J.M. (2020). Scientists' warning on invasive alien species. Biological Reviews, 95(6), 1511-1534.

Roy, H. E., Pauchard, A., Stoett, P. J., Renard Truong, T., Meyerson, L. A., Bacher, S., ... & Ziller, S. R. (2024). Curbing the major and growing threats from invasive alien species is urgent and achievable. Nature Ecology & Evolution, 8(7), 1216-1223.