Group Co-Chairs: Richard Griffiths and Gemma Harding

ASG Secretariat Lead Contact: Sally Wren (swren[at]


Amphibian species surviving in self-sustaining populations so that reintroductions are no longer required.


Threats understood and either neutralised, mitigated or managed for priority species and habitats.

Reintroductions undertaken for priority species.

Monitoring data show that reintroductions have established viable populations in the wild, or are on a trajectory towards viability.

Improved understanding of how to carry out successful amphibian translocations and post release monitoring, including improving methods and understanding the biology behind these reintroductions.

Publication and dissemination of results from both successful and unsuccessful reintroductions.

Key variables linked to reintroduction success identified, disseminated and incorporated into reintroduction planning.


Insufficient resources

Although there are now more resources being invested in amphibian conservation than ever before, compared to other taxa amphibians remain grossly underfunded. Funding for reintroductions comes from a diversity of sources but is often piecemeal and localised. In addition to fundamental resources for the design and execution of reintroductions, there also needs to be improved analysis, documentation and dissemination of results on a global scale.

Insufficient technical expertise

As several analyses have shown, most conservation effort is carried out by experts working on non-priority species in areas that are not globally important for biodiversity. Although there are local and regional initiatives to rectify this imbalance, there remain significant challenges in building the capacity and technical expertise required for reintroductions in those parts of the world where it is most needed.

Current threats not understood

Although our understanding of the threats that amphibians face has increased considerably over the past two decades, significant barriers remain. As the identification and neutralisation of threats is a fundamental first step in species recovery, reintroduction can be risky without a full understanding of these issues. Although this problem is particularly acute in parts of the world where there are high levels of amphibian species richness but a poor understanding of their natural history, some well-researched species in Europe and North America continue to pose challenges in this respect.

New threats emerging

Even if they are well-understood in themselves, climate and environmental change may result in conditions under which new threats can emerge and thrive. Novel pathogens and invasive species pose a particular problem here. Reintroduction may therefore involve releasing animals into an environment that is very different from that which the source animals originally came.

Lack of robust field data on population status

Amphibians are often small, cryptic and highly seasonal and these characteristics pose challenges for reliable population assessment. Establishing the baseline population status for monitoring programmes is an essential precursor for a reintroduction and appropriate methods and protocols need to be in place to facilitate this.

Lack of field data on population biology and life history

Unless the data can shed light on wider problems, single species projects focusing on basic life history information (i.e. survival, fecundity, population size) are becoming increasingly unfashionable within research and funding agendas. However, such life history information is essential for providing a template for identifying and designing interventions such as reintroductions.

Ex-situ management produces maladapted amphibians

Some amphibians fail to thrive and breed in in captivity. The husbandry requirements of amphibians are more complex than previously thought and there is a danger or producing maladapted amphibians in ex situ breeding programmes which may not be suitable for reintroduction.

Risk of novel pathogens in ex situ facilities

Ideally, conservation breeding facilities should be located within the range or former distributional range of a species to minimise the risk of individuals in such programmes becoming exposed to novel pathogens. Capacity may be lacking in some regions, as a result facilities may need to be located outside of the target species range state and there is a risk that such populations of amphibians will become exposed to novel pathogens.

National, regional or local conservation authorities unsupportive

Conservation priorities depend on the scale of operation. A regionally threatened species may not be a national or global priority, and vice versa. This can result in different priorities within organisations operating at different scales. Equally, the level of support provided will depend on the political motivations of the authorities concerned.

Lack of appropriate and protected release sites for some species

Even with Critically Endangered species, all of the favourable habitat that is available may be already occupied by the species. Identifying, creating, restoring and managing release sites may therefore be problematical.

Lack of knowledge on the best way to reintroduce some species

This aspect of amphibian reintroduction has developed in recent years, and we now have a better understanding of such issues as identifying appropriate life stages for release, timing of releases, mechanisms for releases etc. There remain gaps in terms of assessment of fitness of release stock, behaviour following release, and ‘soft’ versus ‘hard’ releases.

Lack of sufficient numbers or genetic diversity for founding populations

Genetic analysis is expensive and the resources and expertise are not available to determine the genetic viability of many populations that would benefit from it. Consequently, when they are carried out they are often part of a wider research project.

Postponing management actions until founder populations have become dangerously low 

Shifting and conflicting conservation priorities often means that interventions are not actioned until a population has reached a dangerously low level. By this time, the species may already be in an ‘extinction vortex’, and the remaining habitat may be unable to support a viable population.

Inadequate pre-release health screening

Some amphibian pathogens are difficult to screen for both ante and post mortem. Animals destined for reintroduction may have subclinical infections that are not detectable with current pathogen screening techniques. This may pose a threat to sympatric amphibians at the release site.

Difficulties with post release monitoring

Reintroductions should be followed up with appropriate post release monitoring so that the success of the reintroduction can be evaluated and future conservation actions determined. Many amphibian species are often small, cryptic and highly seasonal and these characteristics pose challenges for post release monitoring. Funding for longitudinal post release monitoring should be identified prior to any reintroduction.

Current Priority Actions

Constraint / ActionMid-term Priorities (1–5 years)Short-term Targets (6–12 months)
Identification of long-term protection for and restoration of reintroduction sitesNational and local governments have effective instruments in place for protection and restoration of reintroduction sitesIncrease the urgency within national and local governments for the identification and protection of sites that are important for amphibians
Fundraising to carry out reintroductions and appropriate post-release monitoringHigh priority reintroduction programmes fundedRecruit entrepreneurial ‘amphibian champions’ to identify and access sources of funding
Training and capacity building in regions/agencies short of expertisei. All areas of the world that have high levels of amphibian species richness will have had a training and capacity building programme delivered regionally;
ii. All relevant expertise in the key regions will have been identified and trained
i. Support and develop initiatives with existing training providers (e.g. Durrell Wildlife);
ii. Identify gaps in training and capacity building coverage
Identify most appropriate reintroduction methodsProduce reintroduction guidelines for amphibians to complement current IUCN SSC guidelinesi. Establish central open-access database for amphibian reintroductions;
ii. Carry out systematic evidence review/meta-analysis of factors affecting reintroduction success;
iii. On the basis of the review identify research shortfalls and most appropriate methods;
iv. Refine protocols for amphibian reintroductions
Research to identify threats and mitigate threatsThreat neutralization, mitigation and management plans in place for newly identified threatsContinue to carry out, support and disseminate research aimed at identifying threats, such as novel pathogens and invasive species
Identify and prioritise species appropriate for reintroductionDelivery of prioritised list of reintroduceable amphibian species and projectsAssessment – The AARK prioritisation process has already made a start on this issue through its regional assessment workshops. However, some amphibians may not require a captive component for reintroduction. ‘Reintroduceability’ of species needs to be assessed on the basis of data on (1) current population status; (2) potential for threat neutralization; (3) available habitat; (4) national and local stakeholder support; (5) availability of stock for release; (6) viability of reintroduced population; (7) inability of the species to respond to alternative interventions (e.g. habitat restoration); (8) Life history characteristics, particularly generation time; fecundity and mode of reproduction.
Formulation of appropriate survey protocols to assess population status and habitat assessmentEstablish appropriate population and habitat survey protocols for all priority species for reintroductioni. Continue to work with biostatisticians to ensure that new developments in statistical modelling are embraced within survey design and analysis protocols;
ii. Continue to develop novel tools for the assessment of populations (e.g. environmental DNA);
iii. Continue to utilise new tools in GIS and spatial and landscape ecology to identify and assess habitats.
Inadequate pre-release health screeningContinue to work with wildlife specialists to ensure that the disease screening protocols are up to date and of the highest possible standard
Difficulties with post release monitoringContinue to develop novel tools for the assessment of individuals and populations

ACAP Related Chapters

Chapter 8. Reintroductions (R. Griffiths, K. Buhlmann, J. McKay, and T. Tuberville).

Read the whole ACAP here.