•Translocated individuals had much larger territories in comparison with the residents.•The males and the adults were significantly more mobile than the females and juveniles.•The survival of the ...translocated individuals was 79%, main reason for death was predation.•Results can be used for better planning of the future translocations.
The spatial behaviour of 47 European ground squirrels (Spermophilus citellus) was investigated through radio-collars in the frame of a conservation project for population reinforcement in south-eastern Bulgaria. For the first time both translocated and resident individuals were collared. After the release, each individual’s movement was followed hourly through triangulation during the day and the sleep sites were localised by radio-tracking in the evening. The results showed that the translocated individuals had much larger territories in comparison with the residents. The males and the adults were significantly more mobile than the females and juveniles. Considerable relocation was observed in more than one third of the translocated individuals between the 5th and the 10th day after the release. The main reason for death was predation. The survival of the translocated individuals at the end of the first active season after the translocation was 79%. Recommendations for future Spermophilus citellus conservation translocations were drawn.
Abstract The colonization of suitable yet unoccupied habitat due to natural dispersal or human introduction can benefit recovery of threatened species. Predicting habitat suitability and conflict ...potential of colonization areas can facilitate conservation planning. Planning for reintroduction of gray wolves ( Canis lupus ) to the US state of Colorado is underway. Assessing which occupancy sites minimize the likelihood of human–wolf conflict during dispersal events and seasonal movements is critical to the success of this initiative. We used a spatial absorbing Markov chain (SAMC) framework, which extends random walk theory and probabilistically accounts for both movement behaviour and mortality risk, to compare the viability of potential occupancy sites (public lands >500 km 2 to minimally meet wolf pack range area). The SAMC framework produced spatially explicit predictions of wolf dispersal, philopatry and conflict risk ahead of recolonization prior to reintroduction efforts. Our SAMC model included: (1) movement resistance based on terrain, roads and housing density; (2) mortality risk and potential conflict (absorption) based on livestock presence, social tolerance, land ownership and state boundaries; and (3) site fidelity based on habitat quality. Using this model, we compared 21 public land units by deriving predictions of: (A) relative survival time outside each site, (B) intensity of use and retention time within each site and (C) the probability of use on adjacent public lands. We also predicted and mapped potential conflict hotspots associated with each site. Among the units assessed, a complex of USFS Wilderness areas near Aspen, chiefly the Hunter‐Fryingpan and Collegiate Peaks Wilderness areas, had the best overall rankings when comparing predictions of each metric. The area balances high‐quality, well‐connected habitat with relatively low livestock density and high social tolerance. Synthesis and applications . Our findings highlight the utility of the SAMC framework for assessing colonization areas and the capacity to identify locations for effective proactive management, especially of conflict prone species. The flexibility of the SAMC framework enables predicting likely areas of philopatry and human–wildlife conflict using spatially explicit metrics which can improve the success of conservation translocations and management of species with changing geographic extents.
Conservation translocation is a common method for species recovery, for which one increasingly frequent objective is restoring lost ecological functions to promote ecosystem recovery. However, few ...conservation translocation programs explicitly state or monitor function as an objective, limiting the ability to test assumptions, learn from past efforts, and improve management. We evaluated whether translocations of hihi (Notiomystis cincta), a threatened New Zealand passerine, achieved their implicit objective of restoring lost pollination function. Through a pollinator‐exclusion experiment, we quantified, with log response ratios (lnR), the effects of birds on fruit set and seed quality in hangehange (Geniostoma ligustrifolium), a native flowering shrub. We isolated the contributions of hihi by making comparisons across sites with and without hihi. Birds improved fruit set more at sites without hihi (lnR = 1.27) than sites with hihi (lnR = 0.50), suggesting other avian pollinators compensated for and even exceeded hihi contributions to fruit set. Although birds improved seed germination only at hihi sites (lnR = 0.22–0.41), plants at sites without hihi had germination rates similar to hihi sites because they produced 26% more filled seeds, regardless of pollination condition. Therefore, although our results showed hihi improved seed quality, they also highlighted the complexity of ecological functions. When an important species is lost, ecosystems may be able to achieve similar function through different means. Our results underscore the importance of stating and monitoring the ecological benefits of conservation translocations when functional restoration is a motivation to ensure these programs are achieving their objectives.
Evaluación del Éxito de la Restauración Funcional Posterior a la Reintroducción de un Ave Polinizadora Desaparecida
Resumen
La reubicación para la conservación es un método común para la recuperación de especies en el cual un objetivo cada vez más frecuente es la restauración de las funciones ecológicas que se perdieron para promover la recuperación del ecosistema. Sin embargo, pocos programas de reubicación para la conservación establecen o monitorean explícitamente a la función como un objetivo, lo que limita la posibilidad de comprobar suposiciones, aprender de esfuerzos anteriores y mejorar la gestión. Analizamos si las reubicaciones de hihi (Notiomystis cincta), un ave paseriforme amenazada de Nueva Zelanda, lograron el objetivo implícito de restaurar la desaparecida función de polinización. Mediante un experimento de exclusión del polinizador, cuantificamos con relaciones de respuesta logarítmica (lnR) los efectos de las aves sobre el conjunto de frutos y la calidad de la semilla del arbusto floral nativo Geniostoma ligustrifolium. Aislamos las contribuciones del hihi cuando comparamos entre sitios con y sin su presencia. Las aves favorecieron más al conjunto de frutos en sitios sin hihi (lnR = 1.27) que en los sitios con hihi (lnR = 0.50), lo que sugiere que otras aves polinizadoras compensaron y excedieron las contribuciones del hihi al conjunto de frutos. Aunque las aves aumentaron la germinación de semillas sólo en sitios con hihi (lnR = 0.22‐0.41), las plantas en los sitios sin hihi tuvieron tasas de germinación similares a los sitios con hihi porque produjeron 26% más de semillas completas sin importar la condición de la polinización. Por lo tanto, aunque nuestros resultados mostraron mejoras en la calidad de la semilla a causa del hihi, también resaltaron la complejidad de las funciones ecológicas. Cuando desaparece una especie importante, puede que los ecosistemas logren una función similar por medio de diferentes métodos. Nuestros resultados hacen hincapié en la importancia que tiene establecer y monitorear los beneficios ecológicos de las reubicaciones para la conservación cuando la restauración es motivo para asegurar que estos programas están logrando sus objetivos.
Article Impact Statement: Conservation translocations can help restore ecosystem function, but functional objectives must be stated and monitored to maximize success.
Wild egg collection can be a powerful tool in avian conservation management. It can be used to establish and augment captive breeding programs for conservation translocations, mitigate low ...productivity during incubation in wild populations, and further research on reproductive and environmental biology. Such benefits need to be balanced against potential risks, like detrimental demographic effects on source populations and disease transfer. A lack of thorough consideration and evaluation of associated benefits, risks, and trade-offs may prevent conservation managers from effectively utilising this powerful conservation tool, and may lead to poor management outcomes for wild populations. Structured decision making (SDM) can offer a framework for making decisions in the presence of uncertainty about how a system will respond to different management alternatives. We therefore advocate for the use of SDM to explore whether an egg collection program is a desirable management tool and, if so, to assess how new data iteratively informs decisions throughout all stages of the recovery program. Here, we review the current literature evaluating the practice of wild egg collection, provide an overview of the SDM process, and then use the whooping crane (Grus americana) as an example of how to conduct such an evaluation. Our overall aim is to provide guidance on how SDM can help develop best practice for responsible egg collection from wild populations to enable efficient and effective recovery of endangered avian species.
•Wild egg collection can lead to poor management outcomes when not evaluated.•Structured decision making can offer a framework for evaluating and making decisions.•We explore the SDM process with a whooping crane case study.•We provide conceptual guidance on the SDM process for wild egg collection.
In November 2016, the Scottish Government announced that they were minded to allow the two 'trial' reintroduced populations of Eurasian beaver Castor fiber to remain in Scotland and be allowed to ...expand naturally, and that the species will receive legal protection. This was a historic moment: the first formally approved reintroduction of a mammal species anywhere in the United Kingdom.
The issues surrounding beaver reintroduction to Scotland had been the subject of intense investigation and public debate over the previous 21 years. Extensive multidisciplinary and interdisciplinary work was performed to assess the desirability and feasibility of reintroducing the Eurasian beaver and informed the government's decision. This was one of the most detailed assessments carried out for any species reintroduction proposal.
The work was broadly divided into desk‐based and stand‐alone studies based primarily on the European and North American experience of living with beavers, the scientifically monitored Scottish Beaver Trial reintroduction in west Scotland, a study of beavers resulting from unauthorised releases in an east Scotland catchment and the work of a specialist group that examined beaver–salmonid interactions and issues.
It was confirmed that beavers have a very positive influence on biodiversity overall, although some specific species and habitats of high conservation importance can be adversely affected if appropriate management is not in place. Beavers provide a range of ecosystem services with the potential for socio‐economic benefits. However, beavers' activities may affect some land uses, the extent and significance depending on local conditions. Management techniques are well developed, although some will require refinement and appropriate licensing within a Scottish regulatory regime. A strategic approach to developing management throughout Scotland will need to be progressed in partnership with key stakeholders.
Reintroduction has often been used as a technique for re‐establishing self‐sustaining animal populations that have become extinct within their indigenous range. To achieve conservation success, it is ...essential to accurately assess the demographic parameters and the IUCN Red List criteria of the population. However, acquiring data on all indicators and estimating criteria according to established definitions can be challenging. Here, we developed an integrated population model (IPM) and population viability analysis (PVA) framework to estimate all demographic parameters and criteria for a reintroduced population of Crested Ibis Nipponia nippon, and to project population dynamics under a range of release scenarios on Sado Island, Japan. Our IPM‐PVA framework integrated roost count and mark–resight data for 415 released and 203 wild‐hatched individuals, as well as reproductive performance for a total of 575 pairs. We aimed to assess survival, reproductive success, population size, number of mature individuals and population projection. In the first year after release, the estimated apparent annual survival rate was 0.566 Bayesian credible intervals (CRI) 0.518–0.614; however, this rate increased after 1 year (0.865; CRI 0.836–0.892). Wild‐hatched juveniles exhibited a high survival rate (0.757; CRI 0.670–0.838) that was just lower than that of adults (0.899; CRI 0.844–0.949). The reproductive success rate varied with pair attributes (released–released pair: 0.245, CRI 0.194–0.299; released–wild pair: 0.377, CRI 0.281–0.471; wild–wild pair: 0.350, CRI 0.237–0.471). Total population size was estimated to be 457 individuals (CRI 384–525), with 261 mature individuals (CRI 211–304) in June 2021. The probability of Crested Ibis extinction in the next five generations was 0%, even if the release was discontinued. Our comprehensive case study demonstrated the effectiveness of IPM‐PVA for the evaluation of ongoing reintroduction programmes.
Globally, translocations are commonly used to improve the conservation status of threatened species. There is increasing recognition that translocations of ecosystem engineers also have the potential ...to restore ecological processes. Digging mammals are often considered to be ecosystem engineers, as their diggings provide shelter for other species and can significantly alter soil properties, with subsequent changes to vegetation.
Using Australian species as a case study, we reviewed published and grey literature on digging mammal translocations to determine how often these translocations are conducted to restore ecosystem processes. We documented ecosystem‐level monitoring and research efforts, and assessed whether restoration was perceived to be occurring post‐release.
At least 208 translocations of 24 digging mammal species have been conducted in Australia, with a further 38 planned for the near future. Prior to 2019, only 3% of translocations included a goal relating to the restoration of ecosystem processes associated with digging activities. Nearly a quarter of pre‐2019 translocations have been the subject of some form of ecosystem‐level monitoring or research, but long‐term ecosystem‐level monitoring was very rare. In contrast, 74% of the translocations planned for post‐2018 include a goal relating to the restoration of ecological processes and most also include plans to conduct ecosystem‐level monitoring.
Ecosystem restoration was perceived to be occurring for 26% of the pre‐2019 translocations. None of the documents we reviewed indicated that ecological degradation had occurred post‐translocation, even when declines in other taxa were recorded.
The restoration of ecosystem processes is increasingly being identified as a goal for translocation programmes. Where this is the case, we suggest that translocation practitioners include success criteria for the restoration of ecosystem processes, and commit to long‐term monitoring designed to detect ecosystem‐level effects of translocations.
There is increasing recognition that translocations of ecosystem engineers, such as digging mammals, have the potential to restore ecological processes. We reviewed Australian digging mammal translocations to determine how often they are conducted to restore ecosystem processes. We found that, prior to 2019, very few translocations included a goal relating to the restoration of ecosystem processes. In contrast, most of the translocations planned for 2019 onwards include a goal relating to the restoration of ecological processes. Ecosystem restoration was perceived to be occurring for 26% of the translocations. We recommend that translocation practitioners include success criteria for the restoration of ecosystem processes, and conduct long‐term monitoring designed to detect ecosystem‐level effects of translocations, when restoration of ecosystem processes is identified as a goal. This image shows a warren constructed by a translocated population of an Australian digging mammal, Bettongia lesueur. Soil disturbances like this warren alter soil properties, affect plant species composition and abundance and provide shelter for other fauna.
Kenngoor (
Phascogale calura
) persist in < 1% of their original distribution, occupying highly fragmented remnant habitat in south-west Western Australia, with very little known of the genetic ...diversity of the remaining wild populations. Recently, the species has been translocated to managed reserves to improve its conservation. Understanding genetic structure and patterns of genetic diversity is crucial to inform conservation translocations for species recovery. This study aims to (1) assess genetic structure and genetic diversity across remaining wild locations, (2) assess long-term genetic outcomes of a mixed-source wild-to-wild translocation, and (3) estimate global effective population size. We genotyped 209 samples from 13 locations of fragmented remnant habitat using reduced representation sequencing. An isolation by distance model best explained genetic structure across the survey areas, with evidence of fine scale divergence of two northern locations. Allelic richness and autosomal heterozygosity measures indicated that diversity is spread uniformly across locations, and no locations showed signs of inbreeding or strong genetic drift. The mixed-source translocation has retained the diversity of the wider species ten years post-translocation. Overall, our results suggest that connectivity between survey areas has largely been maintained and that no location has substantially lower genetic diversity, despite the highly fragmented nature of remnant kenngoor habitat. Future translocations should aim to represent a mixture of genetically divergent locations to maintain the diversity present at the species level. Ongoing conservation management will be required to ensure the long-term viability of the species in this fragmented landscape.
Species distribution models (SDMs) are often used during the planning stage of reintroduction programmes to model species' occurrence with the aim of selecting potential release sites. However, for ...many endangered species, only a low number of records are available, leading to models with low accuracy. When planning reintroductions for rare species, an alternative approach may be to model surrogate species that are more abundant or easier to locate. Here, we modelled the distribution of white gum (Eucalyptus viminalis), the preferred food tree of the forty‐spotted pardalote (Pardalotus quadragintus), a rare songbird for which reintroduction has been proposed. Using boosted regression trees, we modelled white gum distribution under current and future climate conditions with the aim of identifying areas of high probability of occurrence that later can be used to plan on ground habitat assessments for reintroductions. Our model show areas with high probability of white gum occurrence outside its currently mapped distribution, indicating that there may be opportunities for reintroduction of pardalotes beyond their current range. Predictions of future climate scenarios showed climate space shifts, not only with some decrease but also with substantial increase in the probability of suitability for occurrence under some scenarios. Our spatial predictions for white gum may be used to design a survey to ground‐truth our model and undertake a comprehensive habitat assessment for other habitat features forty‐spotted pardalotes need to persist. The approach used in our study may be used for other highly specialized species, not only in the context of reintroduction planning but also in the general management of data‐poor specialist species that depend on a more common resource.
Identifying the molecular mechanisms facilitating adaptation to new environments is a key question in evolutionary biology, especially in the face of current rapid and human‐induced changes. ...Translocations have become an important tool for species conservation, but the attendant small population sizes and new ecological pressures might affect phenotypic and genotypic variation and trajectories dramatically and in unknown ways. In Scotland, the European whitefish (Coregonus lavaretus) is native to only two lakes and vulnerable to extirpation. Six new refuge populations were established over the last 30 years as a conservation measure. In this study, we examined whether there is a predictable ecological and evolutionary response of these fishes to translocation. We found eco‐morphological differences, as functional traits relating to body shape differed between source and refuge populations. Dual isotopic analyses suggested some ecological release, with the diets in refuge populations being more diverse than in source populations. Analyses of up to 9117 genome‐mapped SNPs showed that refuge populations had reduced genetic diversity and elevated inbreeding and relatedness relative to source populations, though genomic differentiation was low (FST = 0.002–0.030). We identified 14 genomic SNPs that showed shared signals of a selective response to translocations, including some located near or within genes involved in the immune system, nervous system and hepatic functions. Analysis of up to 120,897 epigenomic loci identified a component of consistent differential methylation between source and refuge populations. We found that epigenomic variation and genomic variation were associated with morphological variation, but we were not able to infer an effect of population age because the patterns were also linked with the methodology of the translocations. These results show that conservation‐driven translocations affect evolutionary potential by impacting eco‐morphological, genomic and epigenomic components of diversity, shedding light on acclimation and adaptation process in these contexts.
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