REVIEW: Translocation tactics: a framework to support the IUCN Guidelines for wildlife translocations and improve the quality of applied methods

Effectiveness of population-based recovery actions for threatened southern mountain caribou

Habitat loss is affecting many species, including the southern mountain caribou (Rangifer tarandus caribou) population in western North America. Over the last half century, this threatened caribou population's range and abundance have dramatically contracted. An integrated population model was used to analyze 51 years (1973-2023) of demographic data from 40 southern mountain caribou subpopulations to assess the effectiveness of population-based recovery actions at increasing population growth. Reducing potential limiting factors on threatened caribou populations offered a rare opportunity to identify the causes of decline and assess methods of recovery. Southern mountain caribou abundance declined by 51% between 1991 and 2023, and 37% of subpopulations were functionally extirpated. Wolf reduction was the only recovery action that consistently increased population growth when applied in isolation, and combinations of wolf reductions with maternal penning or supplemental feeding provided rapid growth but were applied to only four subpopulations. As of 2023, recovery actions have increased the abundance of southern mountain caribou by 52%, compared to a simulation with no interventions. When predation pressure was reduced, rapid population growth was observed, even under contemporary climate change and high levels of habitat loss. Unless predation is reduced, caribou subpopulations will continue to be extirpated well before habitat conservation and restoration can become effective.

Analyzing captive breeding outcomes to inform reintroduction practice: lessons from the pookila (Pseudomys novaehollandiae)

Captive breeding is often used to produce individuals for reintroduction programs in order to reestablish a species in an area where it has become locally extinct. To maximize the likelihood of establishing a self-sustaining population in the wild, an analysis of data from captive breeding programs is commonly undertaken to (1) increase the quantity of individuals and rate at which they can be released, and (2) maintain or improve the genetic and phenotypic quality of individuals. Here we demonstrate how the knowledge gained from these analyses can also be applied to decision-making during the design of subsequent reintroductions to further advance a reintroduction program toward success. We conducted an analysis of data from a captive breeding program for the threatened pookila (Pseudomys novaehollandiae, New Holland mouse) spanning 6 years. We found evidence for relationships between the reproductive output of pookila and behavioral, demographic, experiential, health, and physiological predictors. Based on a biological interpretation of these results, and with reference to a checklist of all known translocation tactics, we recommend 11 specific design elements to maximize the probability of pookila reproduction postrelease (thereby improving the likelihood of reintroduction success). These recommendations should be interpreted as hypotheses to be evaluated and refined in future reintroduction trials for the pookila. The uncertainty around the postrelease survival and reproduction of a species that is common in reintroduction practice warrants the creative use of existing data to inform adaptive management. Indeed, there is a wealth information in well-kept captive breeding records that is currently underused by reintroduction practitioners. The direct integration of knowledge derived from captive breeding (where available) with decision-making for reintroductions, as described here, will help navigate these uncertainties, which would benefit the conservation of both understudied and well-known species around the world.

Porcupettes Management at Wildlife Rescue Centers and Liberation into the Wild: Implications for Post-Liberation Success

The crested porcupine is a frequent host species in wildlife rescue centers and no guidelines for its management, liberation and post-liberation monitoring are yet available. Here, captive-grown porcupines' behavior and survival in the wild after liberation were investigated and described for the first time. Management strategies adopted at the centers could affect porcupine adaptation to the natural environment. The detention of porcupettes in single cages and fed only human-supplied food may not ensure ethological welfare, nor a suitable behavioral development compatible with wildlife. The liberation of captive-grown porcupines should also be carefully planned to promote and increase the possibility of post-liberation success.

Incorporating human dimensions is associated with better wildlife translocation outcomes

Wildlife translocations are increasingly used to combat declining biodiversity worldwide. Successful translocation often hinges on coexistence between humans and wildlife, yet not all translocation efforts explicitly include human dimensions (e.g., economic incentives, education programs, and conflict reduction assistance). To evaluate the prevalence and associated outcomes of including human dimensions as objectives when planning translocations, we analyze 305 case studies from the IUCN's Global Re-Introduction Perspectives Series. We find that fewer than half of all projects included human dimension objectives (42%), but that projects including human dimension objectives were associated with improved wildlife population outcomes (i.e., higher probability of survival, reproduction, or population growth). Translocation efforts were more likely to include human dimension objectives if they involved mammals, species with a history of local human conflict, and local stakeholders. Our findings underscore the importance of incorporating objectives related to human dimensions in translocation planning efforts to improve conservation success.

A systematic review of snake translocations to identify potential tactics for reducing postrelease effects

Advancements in the field of reintroduction biology are needed, but understanding of how to effectively conduct translocations, particularly with snakes, is lacking. We conducted a systematic review of snake translocation studies to identify potential tactics for reducing postrelease effects. We included studies on intentional, human-mediated, wild-wild, or captive-wild translocations to any location, regardless of motive or number of snakes translocated. Only studies that presented results for at least 1 of 4 outcomes (movement behavior, site fidelity, survival, or population establishment) were included. We systematically searched 4 databases for published studies and used 5 methods to search the gray literature. Our search and screening criteria yielded 121 data sources, representing 130 translocation cases. We quantified the association between 15 translocation tactics and short-term translocation outcomes by calculating odds ratios and used forest plots to display results. Snake translocations involved 47 species (from mainly 2 families), and most were motivated by research, were monitored for at least 6 months, occurred in North America, and took place from the 1990s onward. The odds of a positive snake translocation outcome were highest with release of captive reared or juvenile snakes, release of social groups together, delayed release, provision of environmental enrichment or social housing before release, or minimization of distance translocated. The odds of a positive outcome were lowest when snakes were released early in their active season. Our results do not demonstrate causation, but outcomes of snake translocation were associated with 8 tactics (4 of which were strongly correlated). In addition to targeted comparative studies, we recommend practitioners consider the possible influence of these tactics when planning snake translocations.

The Search for Suitable Habitats for Endangered Species at Their Historical Sites-Conditions for the Success of Salix lapponum and Salix myrtilloides Reintroduction

Restoring endangered plant species to their historical sites is not always possible due to constantly changing habitat conditions. The aim of this study was to test the effects of reintroduction of two relict willow species in eastern Poland. The experiment consisted of planting 48 individuals of Salix lapponum and S. myrtilloides, obtained by micropropagation, at each of the two selected sites and observing their survival after one year. At the same time, selected physicochemical and biocenotic factors of the environment were monitored. About 70% of S. lapponum individuals and 50% of S. myrtilloides plants survived the one-year period. This result can be considered satisfactory and confirms the effectiveness of this means of active protection. The results of measurements of selected abiotic factors of the environment and the observations and ecological analysis of the flora indicated that the habitat conditions of both historical sites have changed, resulting in accelerated succession of vegetation. However, complete habitat degradation did not occur, although the development of a multi-story structure of one of the phytocenoses intensified competition for light and other environmental resources, which narrowed the potential ecological niche of the reintroduced species.

Demography and life-history parameters of mantled howler monkeys at La Flor de Catemaco: 20 years post-translocation

Translocations usually aim at maintaining and enhancing wild populations. Thus, the long-term monitoring of translocated individuals is critical for assessing translocation success. In this study, we report the demographic and life-history parameters of mantled howler monkeys that were translocated to La Flor de Catemaco (Los Tuxtlas, Mexico) to determine the success of the translocation process. Nine individuals belonging to two social groups living in areas that were going to be destroyed were released into La Flor de Catemaco between 2002 and 2004. Before 2022 there were no resident monkeys at the site. From January 2012 to December 2021, we recorded births, deaths, migrations, and group formation (1535 sampling days). The population grew until reaching 35 mantled howler monkeys. Two new groups including both individuals born at the site and migrants were founded. Mean ± SD group size was 8.1 ± 1.1 individuals. We recorded 42 births and 14 deaths, mostly of young infants (< 6 months of age). We recorded emigrations and immigrations of adult and immature individuals as well as several instances of individuals that remained and reproduced in their natal groups. Mean female age at first birth was 57.8 ± 18.5 months, interbirth intervals were 23.3 ± 11.3 months, and birth rates were 0.5 ± 0.2 births per female per year. The growth and persistence of the groups at the site, as well as similarity in demographic and life-history parameters between this and unmanaged populations, suggest that mantled howler monkeys living at La Flor de Catemaco represent a stable population and thus that this was a successful translocation.

Responses to environmental enrichment are associated with personality characteristics in chestnut-bellied seed finches (Sporophila angolensis)

Environmental enrichment (EE) is used to promote natural behaviours in captive animals and may hold promise as a form of pre-release training, a strategy for improving coping skills of translocated birds. We investigated the use of EE to enhance foraging and vigilance behaviours of captive Sporophila angolensis, which may be related to post-release survival. We also evaluated whether consistent individual behavioural differences affected birds' responses to EE. We submitted 19 captive seed-finches to three short-term challenges: tonic immobility (TI), new environment (NE) and new object (NO) tests. TI behaviour is related to fear/escape response to potential predators and novelty tests (NE and NO) assess neophobia, which are ecologically relevant personality traits influencing the shyness-boldness continuum. We noted a pronounced variability among the individuals' personality traits, both in their fear and escape-related responses in the TI test and along shy/bold z-scores in NE and NO tests. During a period of enrichment, birds spent more time foraging and less time in vigilance states compared with both control phases. Personality traits of the birds affected their responses to enrichment with bolder birds spending more time foraging. The EE-related decrease in vigilance was independent of the birds' personality traits. Our findings highlight interactions between personality and rearing environment that may impact post-release outcomes for translocated animals.

Social feasibility assessments in conservation translocations

Improving the effectiveness of conservation translocations could contribute to reversing global biodiversity loss. Although evaluations of ecological factors affecting translocation outcomes are commonplace, consideration of human social factors remains rare, hindering improvements to this conservation practice. We analysed 550 translocation case studies to explore the inclusion of social factors in project feasibility assessments. Reviewed projects often failed to assess social feasibility, and assessments, where attempted, tended to be narrow in scope. Consequently, challenges such as proactively addressing conflict often remained unaddressed. Insufficient knowledge sharing and prioritisation of ecological feasibility, to the detriment of social feasibility, remain barriers to effective planning. Successful outcomes of translocations are linked to early assessment of social feasibility and to the establishment of long-term commitments between people, places, and partners.

Mini Safe Havens for population recovery and reintroductions 'beyond-the-fence'

In response to the ongoing decline of fauna worldwide, there has been growing interest in the rewilding of whole ecosystems outside of fenced sanctuaries or offshore islands. This interest will inevitably result in attempts to restore species where eliminating threats from predators and competitors is extremely challenging or impossible, or reintroductions of predators that will increase predation risk for extant prey (i.e., coexistence conservation). We propose 'Mini Safe Havens' (MSHs) as a potential tool for managing these threats. Mini Safe Havens are refuges that are permanently permeable to the focal species; allowing the emigration of individuals while maintaining gene flow through the boundary. Crucial to the effectiveness of the approach is the ongoing maintenance and monitoring required to preserve a low-to-zero risk of key threats within the MSH; facilitating in-situ learning and adaptation by focal species to these threats, at a rate and intensity of exposure determined by the animals themselves. We trialled the MSH approach for a pilot reintroduction of the Australian native New Holland mouse (Pseudomys novaehollandiae), in the context of a trophic rewilding project to address potential naïveté to a reintroduced native mammalian predator. We found that mice released into a MSH maintained their weight and continued to use the release site beyond 17 months (525 days) post-release. In contrast, individuals in temporary soft-release enclosures tended to lose weight and became undetectable approximately 1-month post-release. We discuss the broad applicability of MSHs for population recovery and reintroductions 'beyond-the-fence' and recommend avenues for further refinement of the approach.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s10531-022-02495-6.

Novel viral and microbial species in a translocated Toutouwai (Petroica longipes) population from Aotearoa/New Zealand

BACKGROUND

Translocation is a common tool in wildlife management and its implementation has resulted in many conservation successes. During translocations, any associated infectious agents are moved with their wildlife hosts. Accordingly, translocations can present a risk of infectious disease emergence, although they also provide an opportunity to restore natural infectious communities ('infectome') and mitigate the long-term risks of reduced natural resistance.

METHODS

We used metatranscriptomic sequencing to characterise the cloacal infectome of 41 toutouwai (North Island robin, Petroica longipes) that were translocated to establish a new population within the North Island of New Zealand. We also screened for pathogenic bacteria, fungi and parasites.

RESULTS

Although we did not detect any known avian diseases, which is a positive outcome for the translocated toutouwai population, we identified a number of novel viruses of interest, including a novel avian hepatovirus, as well as a divergent calici-like virus and four hepe-like viruses of which the host species is unknown. We also revealed a novel spirochete bacterium and a coccidian eukaryotic parasite.

CONCLUSIONS

The presumably non-pathogenic viruses and microbial species identified here support the idea that most microorganisms likely do not cause disease in their hosts, and that translocations could serve to help restore and maintain native infectious communities. We advise greater surveillance of infectious communities of both native and non-native wildlife before and after translocations to better understand the impact, positive or negative, that such movements may have on both host and infectome ecology.

The antique genetic plight of the Mediterranean monk seal (Monachus monachus)

Disentangling the impact of Late Quaternary climate change from human activities can have crucial implications on the conservation of endangered species. We investigated the population genetics and demography of the Mediterranean monk seal (Monachus monachus), one of the world's most endangered marine mammals, through an unprecedented dataset encompassing historical (extinct) and extant populations from the eastern North Atlantic to the entire Mediterranean Basin. We show that Cabo Blanco (Western Sahara/Mauritania), Madeira, Western Mediterranean (historical range) and Eastern Mediterranean regions segregate into four populations. This structure is probably the consequence of recent drift, combined with long-term isolation by distance (R2 = 0.7), resulting from prevailing short-distance (less than 500 km) and infrequent long-distance dispersal (less than 1500 km). All populations (Madeira especially), show high levels of inbreeding and low levels of genetic diversity, seemingly declining since historical time, but surprisingly not being impacted by the 1997 massive die-off in Cabo Blanco. Approximate Bayesian Computation analyses support scenarios combining local extinctions and a major effective population size decline in all populations during Antiquity. Our results suggest that the early densification of human populations around the Mediterranean Basin coupled with the development of seafaring techniques were the main drivers of the decline of Mediterranean monk seals.

A systematic review of factors affecting wildlife survival during rehabilitation and release

Millions of native animals around the world are rescued and rehabilitated each year by wildlife rehabilitators. Triage and rehabilitation protocols need to be robust and evidence-based, with outcomes consistently recorded, to promote animal welfare and better understand predictors of wildlife survival. We conducted a global systematic review and meta-analysis of 112 articles that reported survival rates of native mammals and birds during rehabilitation and after release to determine intrinsic and extrinsic factors associated with their survival. We assessed survival during rehabilitation and in the short- and long-term post-release, with the hypothesis that survival will vary as a function of species body size, diel activity pattern, trophic level and study location (region of the world). We aimed to determine the direction of effect of these factors on survival to assist in decision-making during triage and rehabilitation. Results showed that mammals and birds were equally likely to survive all stages of rehabilitation, and survival rates varied between locations. Birds in North America had the poorest survival rates post-release, particularly long-term, as did diurnal and carnivorous birds in the short-term post-release. Anthropogenic factors such as motor vehicle collisions and domestic or feral animal attack contributed to morbidity and post-release mortality in 45% (168 of 369) of instances. The reasons for rescue and associated severity of diagnosis were commonly reported to affect the likelihood of survival to release, but factors affecting survival were often species-specific, including bodyweight, age, and characteristics of the release location. Therefore, evidence-based, species-specific, and context-specific protocols need to be developed to ensure wildlife survival is maximised during rehabilitation and post-release. Such protocols are critical for enabling rapid, efficient rescue programs for wildlife following natural disasters and extreme weather events which are escalating globally, in part due to climate change.

Timing of Release Influence Breeding Success of Translocated Captive-Bred Migrant Asian Houbara Bustard

In conservation translocation, released animals should have comparable fitness to their wild counterparts to effectively contribute to the species demography. Captive-bred animals frequently exhibit lower fitness performances, which can often be attributed to an inadequate release strategy. Untimely release of migrant animals may interfere with key events such as their migration and breeding. In Kazakhstan and Uzbekistan, declining wild populations of Asian houbara (Chlamydotis macqueenii) are reinforced in their breeding grounds with captive-bred individuals. Using data from 6 years of monitoring, we compare eight breeding traits and the productivity of wild and captive-bred females released in two distinct seasons (autumn vs. spring) considering the effects of age and time in the season. Females released in the spring nest prior to their first migration, and females released in the autumn nest following their first migration. Our results highlight that captive-bred and wild females have similar breeding traits and productivity. Breeding probability, laying date, and egg volume varied, depending on the release season and female age. One-year-olds released in autumn have a significantly lower breeding probability compared to wild and spring-released females. However, 1-year-old females released in the spring nest later and lay smaller eggs than wild and autumn-released birds; effects which appear to be carried over with age. Age has a positive effect on breeding probability, egg volume, re-clutching probability and advancement of nesting date. These findings suggest a complex interplay of release timing with migration and breeding, resulting in short- and long-term effects on population demography, emphasizing its importance in conservation translocation.

Niche partitioning in an assemblage of granivorous rodents, and the challenge of community-level conservation

Coexistence of competing species in the same foraging guild has long puzzled ecologists. In particular, how do small subordinate species persist with larger dominant competitors? This question becomes particularly important when conservation interventions, such as reintroduction or translocation, become necessary for the smaller species. Exclusion of dominant competitors might be necessary to establish populations of some endangered species. Ultimately, however, the goal should be to conserve whole communities. Determining how subordinate species escape competitive exclusion in intact communities could inform conservation decisions by clarifying the ecological conditions and processes required for coexistence at local or regional scales. We tested for spatial and temporal partitioning among six species of native, granivorous rodents using null models, and characterized the microhabitat of each species using resource-selection models. We found that the species’ nightly activity patterns are aggregated temporally but segregated spatially. As expected, we found clear evidence that the larger-bodied kangaroo rats drive spatial partitioning, but we also found species-specific microhabitat associations, which suggests that habitat heterogeneity is part of what enables these species to coexist. Restoration of natural disturbance regimes that create habitat heterogeneity, and selection of translocation sites without specific competitors, are among the management recommendations to consider in this case. More generally, this study highlights the need for a community-level approach to conservation and the usefulness of basic ecological data for guiding management decisions.

Applying genomics in assisted migration under climate change: Framework, empirical applications, and case studies

The rate of global climate change is projected to outpace the ability of many natural populations and species to adapt. Assisted migration (AM), which is defined as the managed movement of climate-adapted individuals within or outside the species ranges, is a conservation option to improve species' adaptive capacity and facilitate persistence. Although conservation biologists have long been using genetic tools to increase or maintain diversity of natural populations, genomic techniques could add extra benefit in AM that include selectively neutral and adaptive regions of the genome. In this review, we first propose a framework along with detailed procedures to aid collaboration among scientists, agencies, and local and regional managers during the decision-making process of genomics-guided AM. We then summarize the genomic approaches for applying AM, followed by a literature search of existing incorporation of genomics in AM across taxa. Our literature search initially identified 729 publications, but after filtering returned only 50 empirical studies that were either directly applied or considered genomics in AM related to climate change across taxa of plants, terrestrial animals, and aquatic animals; 42 studies were in plants. This demonstrated limited application of genomic methods in AM in organisms other than plants, so we provide further case studies as two examples to demonstrate the negative impact of climate change on non-model species and how genomics could be applied in AM. With the rapidly developing sequencing technology and accumulating genomic data, we expect to see more successful applications of genomics in AM, and more broadly, in the conservation of biodiversity.

Factors Influencing the Post-Release Movements of Translocated Fishers: Implications for Translocation Success

Long distance, post-release movements of translocated wildlife can be a key factor limiting translocation success.  Yet, for many species, we have little or no understanding of factors that influence post-release movements.  Translocations have been important for recovering fisher Pekania pennanti populations across the southern portion of their North American range.  However, little is known about the post-release movements of translocated fishers and how these movements may be influenced by demographic or translocation-process factors.  To restore fishers in Washington State, we moved 90 fishers from central British Columbia and released them at nine sites in the Olympic Fisher Recovery Area on the Olympic Peninsula of Washington from 2008 to 2010. We evaluated post-release movements of 48 fishers to determine both the distance and duration of movements prior to home range establishment.  Fishers moved extensively following their release.  Multi-model selection indicated a high level of support for the hypothesis that post-release movements differed by fisher sex and age; whereas, year of release had no apparent effect on movements, and release date had only a marginal influence on male movements.  Mean distance (± 95% CI) from a release site to a home range was greater for adult males (62.0 ± 19.6 km) than for juvenile males (31.4 ± 16.0 km), adult females (30.9 ± 21.1 km), and juvenile females (29.0 ± 13.5 km).  Mean number of days from release until home range establishment was similar for the sexes, however the variance in movement duration was greater for females.  Twenty-six of 27 females established home ranges over an 11-month period (December-October), while 19 of 21 males did so within a 4-month period (April-July).  Mean home range sizes differed between males (128.3 ± 21.1 km2) and females (63.5 ± 9.0 km2) and were among the largest reported for the species.  A greater proportion of females (18 of 27; 67%) than males (8 of 21; 38%) established home ranges within or partially within the recovery area.  Six females left a previously established home range during the breeding season, presumably to find breeding males.  Given the large distances that fishers can move following release, translocation success could be furthered by releasing individuals at fewer sites in the interior of large reintroduction areas to facilitate greater exposure to a recovery area and greater opportunity to interact with conspecifics and potential mates.

Two species, one island: Retrospective analysis of threatened fauna translocations with divergent outcomes

Translocations are globally a popular tool used with the intention of improving threatened species conservation and re-establishing ecosystem function. While practitioners strive for successful outcomes the failure rate of translocations continues to be high. We demonstrate how predictive modelling can contribute to more informed decision making and hence potentially improve the success rate of translocation programs. Two species, the Djoongari (Shark Bay mouse) Pseudomys fieldi and the golden bandicoot Isoodon auratus barrowensis, were introduced independently to Doole Island in the Exmouth Gulf of Western Australia. We used population viability analysis to critique the outcomes of these translocations and provide an example of how this tool can be incorporated with expert knowledge to predict likely outcomes of translocations. Djoongari did not establish on the island after seven translocations over nine years, while golden bandicoots established a population after just one release event. Retrospective population viability analysis (of data that was unavailable prior to the translocations) predicted and clarified the reasons behind the outcomes of both translocations. Golden bandicoots have considerably higher demographic plasticity than Djoongari, which were never likely to establish on the island. We conclude that the failure of the Djoongari translocation was due to interactions between sparse habitat, native predators and cyclonic storm surges, whereas golden bandicoots have demonstrated habitat flexibility and an ability to recover from multiple natural disasters. As a result we (1) remind conservation planners of the importance of quantifying likely refuges and habitat availability at release sites, (2) suggest practitioners consider how different threats (including natural disasters) may interact at potential release sites and (3) advocate for the incorporation of predictive modelling during the planning stages of translocations, particularly for conservation introductions where no precedent exists for the species’ survival at a particular location.

Monitoring post-release behavioural activity of captive-bred urial (Ovis vignei punjabiensis) at Togh Managara Safari Park Khyber Pakhtunkhwa, Pakistan

The Punjab urial (Ovis vignei punjabiensis) is a globally threatened wild sheep species. In Pakistan the species is legally protected and bred in captivity to release into natural habitats to reinforce wild populations. Vigilance and feeding are critical to survival, though the degree to which captive-bred animals exhibit these behaviours post-release has rarely been investigated. We monitored the daily behaviours of five adult urial after release and classifying behaviours from 0600 hrs to 1800 hrs, replicating each one-hour period twice and recording four observations of each animal per hour. At the herd level, vigilance and feeding behaviours were exhibited equally. Males and females invested equal time in feeding, males were more vigilant (p = 0.001) and more aggressive (p = 0.010), and females were more restful (p = 0.019) or engaged in grooming (p = 0.044) or locomotion (p = 0.002). Females spent more time feeding than being vigilant (p = 0.002). Males maintained high levels of vigilance throughout the day. Patterns of resting 1300 hrs to 1500 hrs and feeding in early morning and late afternoon were common for both sexes. Behaviours classified as 'other' were exhibited equally between sexes. Our results reveal positive indications of captive-bred urial balancing threat detection and energy acquisition post-release and exhibiting natural behaviours and activity patterns. We encourage assessment of survivorship to evaluate long-term effectiveness of captive breeding and release as a candidate restoration programme.

Decision-Making for Rewilding: An Adaptive Governance Framework for Social-Ecological Complexity

Rewilding can be defined as the reorganisation or regeneration of wildness in an ecologically degraded landscape with minimal ongoing intervention. While proposals for rewilding are increasingly common, they are frequently controversial and divisive amongst stakeholders. If implemented, rewilding initiatives may alter the social-ecological systems within which they are situated and thus generate sudden and unforeseen outcomes. So far, however, much of the discourse on the planning and implementation of rewilding has focused on identifying and mitigating ecological risks. There has been little consideration of how rewilding could alter the human components of the social-ecological systems concerned, nor governance arrangements that can manage these dynamics. This paper addresses this gap by proposing a generic adaptive governance framework tailored to the characteristics of rewilding, based on principles of managing complex social-ecological systems. We integrate two complementary natural resource governance approaches that lend themselves to the contentious and unpredictable characteristics of rewilding. First, adaptive co-management builds stakeholder adaptive capacity through iterative knowledge generation, collaboration and power-sharing, and cross-scale learning networks. Second, social licence to operate establishes trust and transparency between project proponents and communities through new public-private partnerships. The proposed framework includes structural and process elements which incorporate a boundary organisation, a decision-into-practise social learning exercise for planning and design, and participatory evaluation. The latter assesses rewilding outcomes and pre-conditions for the continuation of adaptive governance and conservation conflict resolution.

Reproductive ecology of a critically endangered alpine galaxiid

Stocky galaxias Galaxias tantangara is a newly described freshwater fish restricted to a single population, occupying a 3 km reach of a small headwater stream in the upper Murrumbidgee River catchment of south-eastern Australia. This species is listed as critically endangered under IUCN Red List criteria, and knowledge of the species' ecology is critical for future conservation efforts to establish additional populations by translocation and captive breeding. This study details the first account of spawning and reproductive ecology of G. tantangara, including reproductive development, timing of spawning and a description of one spawning site. Peak gonadosomatic index was observed in March/April in males and in October in females. Absolute fecundity ranged from 211 oocytes for a 76 mm length to caudal fork (LCF) fish to 810 oocytes for a 100 mm LCF fish. The observation of spent females in mid-November 2017 and discovery of an egg mass 8 days later suggest that spawning had occurred, and over a relatively short period. Larvae were subsequently detected in monthly electrofishing surveys in December 2017. Findings from this study provide new understanding of existing and future threats to G. tantangara and have important implications for conservation management of not only this species but also other closely related threatened Galaxias species.

Genetic analyses of the parasitic nematode, Parelaphostrongylus tenuis, in Missouri and Kentucky reveal unexpected levels of diversity and population differentiation

Wildlife translocations, which involve the introduction of naive hosts into new environments with novel pathogens, invariably pose an increased risk of disease. The meningeal worm Parelaphostrongylus tenuis is a nematode parasite of the white-tailed deer (Odocoileus virginianus), which serves as its primary host and rarely suffers adverse effects from infection. Attempts to restore elk (Cervus canadensis) to the eastern US have been hampered by disease caused by this parasite. Using DNA sequence data from mitochondrial and nuclear genes, we examined the hypothesis that elk translocated within the eastern US could be exposed to novel genetic variants of P. tenuis by detailing the genetic structure among P. tenuis taken from white-tailed deer and elk at a source (Kentucky) and a release site (Missouri). We found high levels of diversity at both mitochondrial and nuclear DNA in Missouri and Kentucky and a high level of differentiation between states. Our results highlight the importance of considering the potential for increased disease risk from exposure to novel strains of parasites in the decision-making process of a reintroduction or restoration.

Clair C, Coristine L, Higgs E, Smith R, Pellatt M, Beaty C, Cheskey E, Cooke SJ, Crawford L, Davis R, Forbes G, Gadallah F(Z, Kendall P, Mandrak N, Moola F, Parker S, Quayle J, Ray JC, Richardson K, Smith K, Snider J, Smol JP, Sutherland WJ, Vallillee A, White L, Woodley A. Emerging issues for protected and conserved areas in Canada

Horizon scanning is increasingly used in conservation to systematically explore emerging policy and management issues. We present the results of a horizon scan of issues likely to impact management of Canadian protected and conserved areas over the next 5–10 years. Eighty-eight individuals participated, representing a broad community of academics, government and nongovernment organizations, and foundations, including policymakers and managers of protected and conserved areas. This community initially identified 187 issues, which were subsequently triaged to 15 horizon issues by a group of 33 experts using a modified Delphi technique. Results were organized under four broad categories: ( i) emerging effects of climate change in protected and conserved areas design, planning, and management (i.e., large-scale ecosystem changes, species translocation, fire regimes, ecological integrity, and snow patterns); ( ii) Indigenous governance and knowledge systems (i.e., Indigenous governance and Indigenous knowledge and Western science); ( iii) integrated conservation approaches across landscapes and seascapes (i.e., connectivity conservation, integrating ecosystem values and services, freshwater planning); and ( iv) early responses to emerging cumulative, underestimated, and novel threats (i.e., management of cumulative impacts, declining insect biomass, increasing anthropogenic noise, synthetic biology). Overall, the scan identified several emerging issues that require immediate attention to effectively reduce threats, respond to opportunities, and enhance preparedness and capacity to react.

Can evolutionary theories of dispersal and senescence predict postrelease survival, dispersal, and body condition of a reintroduced threatened mammal?

Theories of dispersal and senescence (or aging) predict that dispersal, and ongoing survival and body condition, are influenced by evolutionary drivers, along with intrinsic and extrinsic factors. Such theories are relevant to translocations of animals where high mortality, loss of body condition, and dispersal beyond the area of release are commonly reported. However, these theories have rarely been tested using data from translocations.We explore whether theories of dispersal and senescence, together with biological knowledge and management interventions, can predict rates of postrelease dispersal, survival and change in body condition of a translocated endangered meso-predator, the eastern quoll Dasyurus viverrinus.Captive-bred quolls (n = 60) from three sanctuaries were translocated to an unfenced, predator-managed reserve (Booderee National Park) over 2 years (2018, 2019). Survival, dispersal and body mass were monitored via GPS/VHF tracking and targeted trapping for 45 days postrelease.We found support for the "social subordinate" hypothesis, with smaller quolls dispersing further. Consistent with theories of senescence and the biology of our species, survival was marginally greater for females, and females regained losses in body mass in both years following release. In contrast, males recovered body condition in the first but not the second release as this coincided with breeding. Quolls that originated from the mainland sanctuary were on average heavier at release and, after accounting for weight, dispersed further. Synthesis and applications. Using theory to test outcomes of wildlife translocations can provide insights into patterns across taxa and under different conditions, enabling useful improvements to future fauna translocations. This allows for better predictions to be made about the likelihood of success from proposed translocations, changes to planning to improve outcomes (e.g., modifying sex ratios, individual selection and release cohort), and improved animal welfare as fewer animals are subjected to trials.

Genetic diversity in natural range remnants of the critically endangered hirola antelope

The hirola antelope (Beatragus hunteri) is considered to be the most endangered antelope in the world. In the ex situ translocated population at Tsavo East National Park, calf mortality and the critically low population numbers might suggest low genetic diversity and inbreeding depression. Consequently, a genetic study of the wild population is pivotal to gain an understanding of diversity and differentiation within its range before designing future translocation plans to increase the genetic diversity of the ex situ population. For that purpose, we assessed 55 individuals collected across five localities in eastern Kenya, covering its entire natural range. We used the complete mitochondrial DNA control region and microsatellite genotyping to estimate genetic diversity and differentiation across its range. Nuclear genetic diversity was moderate in comparison to other endangered African antelopes, with no signals of inbreeding. However, the mitochondrial data showed low nucleotide diversity, few haplotypes and low haplotypic differentiation. Overall, the inferred low degree of genetic differentiation and population structure suggests a single population of hirola across the natural range. An overall stable population size was inferred over the recent history of the species, although signals of a recent genetic bottleneck were found. Our results show hope for ongoing conservation management programmes and that there is a future for the hirola in Kenya.

Adapting reintroduction tactics in successive trials increases the likelihood of establishment for an endangered carnivore in a fenced sanctuary

Threatened species recovery programs are increasingly turning to reintroductions to reverse biodiversity loss. Here we present a real-world example where tactics (techniques which influence post-release performance and persistence) and an adaptive management framework (which incorporates feedback between monitoring and future actions) improved reintroduction success. Across three successive trials we investigated the influence of tactics on the effective survival and post-release dispersal of endangered eastern quolls (Dasyurus viverrinus) reintroduced into Mulligans Flat Woodland Sanctuary, Australian Capital Territory. Founders were monitored for 42 days post-release, and probability of survival and post-release dispersal were tested against trial, origin, sex, den sharing and presence of pouch young. We adopted an adaptive management framework, using monitoring to facilitate rapid learning and to implement interventions that improved reintroduction success. Founders released in the first trial were less likely to survive (28.6%, n = 14) than those founders released the second (76.9%, n = 13) and third trials (87.5%, n = 8). We adapted several tactics in the second and third trials, including the selection of female-only founders to avoid elevated male mortality, and post-mating releases to reduce stress. Founders that moved dens between consecutive nights were less likely to survive, suggesting that minimising post-release dispersal can increase the probability of survival. The probability of moving dens was lower in the second and third trials, for females, and when den sharing with another founder. This study demonstrates that, through iterative trials of tactics involving monitoring and learning, adaptive management can be used to significantly improve the success of reintroduction programs.

Adjusting the Prerelease Gut Microbial Community by Diet Training to Improve the Postrelease Fitness of Captive-Bred Acipenser dabryanus

As one of the most important tool for biodiversity restoration and endangered species conservation, reintroduction has been implemented worldwide. In reintroduction projects, prerelease conditioning could effectively increase postrelease fitness and survival by improving animals’ adaptation to transformation from artificial to natural environments. However, how early-life diet training affects individuals’ adaptation, fitness, and survival after release remains largely unknown. We hypothesized that early-life diet training would adjust the host’s gut microbial community, the gut microbial community would influence the host’s diet preference, and the host’s diet preference would impact its adaptation to diet provision transformation and then determine postrelease fitness and survival. To verify this hypothesis, we investigated the growth characteristics and gut microbes of Yangtze sturgeon (Acipenser dabryanus) trained with natural and formula diets at both the prerelease and postrelease stages. The results showed that (1) the gut microbial communities of the individuals trained with a natural diet (i.e., natural diet group) and formula diet (i.e., formula diet group) evolved to the optimal status for their corresponding diet provisions, (2) the individuals in the natural diet group paid a lower cost (i.e., changed their gut microbial communities less) during diet transformation and release into the natural environment than did the individuals in the formula diet group, and (3) the gut microbes in the natural diet group better supported postrelease fitness and survival than did the gut microbes in the formula diet group. The results indicated that better prerelease diet training with more appropriate training diets and times could improve the reintroduction of Yangtze sturgeon by adjusting the prerelease gut microbial community. Because a relationship between diet (preference) and gut microbes is common in animals from insects (such as Drosophila melanogaster) to mammals (such as Homo sapiens), our hypothesis verified by the case study on Yangtze sturgeon applies to other animals. We therefore encourage future studies to identify optimal training diets and times for each species to best adjust its prerelease gut microbial community and then improve its postrelease fitness and survival in reintroduction projects.