Article

Fischer J, Lindenmayer DB.. An assessment of the published results of animal relocations. Biol Conserv 96: 1-11

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Abstract

We reviewed 180 case studies and a number of theoretical papers on animal relocations published in 12 major international scientific journals over the last 20 years. The study focused on re-introductions, supplementations and translocations (sensu IUCN, 1996. IUCN/SSC Guidelines for Re-introductions. 41st Meeting of the IUCN Council, Gland, Switzerland, May 1995. Http://iucn.org/themes/ssc/pubs/policy/hinte.htm.). We did not assess introductions. Re-introductions were the most common type of relocation (116/180); three quarters of these were conducted for conservation purposes. Supplementations (48/180) and translocations (36/180) occurred less frequently, and both were commonly carried out for reasons other than conservation. Simple descriptive statistics were used to analyse factors influencing relocation success. Translocations that aimed to solve human–animal conflicts generally failed. Re-introduction success was not found to have changed over the last two decades, but re-introductions appeared to be more successful when the source population was wild, a large number of animals was released (n>100), and the cause of original decline was removed. More complex trends were found for the effect of predation and the use of supportive measures such as provision of food or shelter, or predator control prior to release. The success of 47% of re-introductions was uncertain at the time case studies were published in journals. This was partly due to the lack of generally accepted and widely applied criteria to assess success. Very few case studies (3%) reported the cost of the relocation attempt. We conclude that there were three primary aims for animal relocations. These were to solve human–animal conflicts, to restock game populations, and conservation. Our extensive review of the present literature leads us to conclude that the value of animal relocations as a conservation tool could be enhanced through (1) more rigorous testing for the appropriateness of the approach in a given case, (2) the establishment of widely used and generally accepted criteria for judging the success or failure of relocations, (3) better monitoring after a relocation, (4) better financial accountability, and (5) greater effort to publish the results of relocations, even ones that are unsuccessful.

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... Despite some high-profile success stories (e.g., Californian Condor brought back from the brink of extinction; Parish and Hunt, 2016), translocations often fail. This is highlighted in global translocation reviews reporting success rates around 50 % or less (Fischer and Lindenmayer, 2000;Bubac et al., 2019;Resende et al., 2021). For mitigation translocations, when the motivation for translocation is to mitigate human-wildlife conflict, successful outcomes are less likely (Germano et al., 2015;Sullivan et al., 2015;Bradley et al., 2022). ...
... Translocation failure is mostly attributed to: (1) increased post-release movement (sometimes representing an attempt to 'home') which reduces survivorship (Butler et al., 2005;Berger-Tal et al., 2020); (2) persistence of threats at release site which led to initial species decline (Letty et al., 2007;Germano and Bishop, 2009); and (3) an inability of translocated animals to quickly locate resources critical to survival (Roe et al., 2010). Conversely, large cohorts of translocated individuals (Fischer and Lindenmayer, 2000;Morris et al., 2021), use of wild-caught animals (Rummel et al., 2016), and implementation of soft-release measures (Resende et al., 2021) can increase the likelihood of success. ...
... The potential benefits of this approach are multifaceted: safeguarding species against regional loss, increasing functional diversity of habitat patches, and engaging the wider public in active conservation management (Watson and Watson, 2015). Translocating common species also has the advantage of potentially large founder populations increasing the likelihood of success (Fischer and Lindenmayer, 2000;Morris et al., 2021), and lower risk of diminishing the viability of source populations (Evans et al., 2022;Mitchell et al., 2022). Further, larger sample sizes of common species can enable true 'experiments' with replicated and controlled manipulations that test specific variables hypothesised to influence translocation success, maximising the potential for learning (Kemp et al., 2015). ...
... Translocations, the deliberate movement of organisms from one location to another (IUCN/SSC 2013), are an effective conservation tool used to recover populations and reduce extinction rates (Berger-Tal, Blumstein, and Swaisgood 2020). However, translocations are inherently risky and prone to failure (Fischer and Lindenmayer 2000), mainly due to their low foundation population numbers (Verbeylen, De Bruyn, and Matthysen 2003) and isolation (Fahrig and Merriam 1985), making them susceptible to extinction. Generally, the success of a translocation is measured by the establishment of a self-sustaining population (Fischer and Lindenmayer 2000). ...
... However, translocations are inherently risky and prone to failure (Fischer and Lindenmayer 2000), mainly due to their low foundation population numbers (Verbeylen, De Bruyn, and Matthysen 2003) and isolation (Fahrig and Merriam 1985), making them susceptible to extinction. Generally, the success of a translocation is measured by the establishment of a self-sustaining population (Fischer and Lindenmayer 2000). However, this definition is controversial as it can only indicate success at the time of assessment and does not necessarily indicate the long-term viability of the population (Seddon 1999). ...
... However, numerous factors can impede this growth, including predation (Moseby et al. 2011;Plein et al. 2016), competition for resources (Danielson and Gaines 1987;Losos and Spiller 1999) and an unsuitable habitat (Blyton et al. 2023;Nafus et al. 2017). Additionally, the failure to remove the original issue prompting the translocation (Fischer and Lindenmayer 2000;Wilson 2018) and social structure disruption (Shier 2006;Shier and Swaisgood 2012) can also hinder population expansion and survival during the growth phase. While these factors may not directly cause mortality in the founding population, their cumulative negative effects may become apparent over time, affecting the overall success of the translocation. ...
Article
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Translocations, a conservation tool used to conserve and restore dwindling species, are often associated with high failure rates. Inadequate long‐term monitoring of both populations and their introduction sites beyond the initial years post‐translocation creates a gap in our understanding of the factors that determine translocation success or failure, resulting in less informed projects in the future. This lack of long‐term monitoring is partly caused by the absence of a well‐defined framework by which the success of the translocation can be measured, leading to premature and sometimes inaccurate assessments of their outcome. We investigated the long‐term outcome of a red squirrel translocation in the west of Ireland, specifically assessing the habitat changes in the translocation site since the introduction in 2005, and their impact on the capacity of the forest to sustain a population of a given size. Using digitised historical map data, we showed that the translocation site experienced a 53% reduction in suitable habitat. Additionally, there was a 41%–81% reduction in the total number of red squirrels the forest could support, according to feeding survey data. Clear‐felling, a forest fire and a shift in tree species composition collectively contributed to this decline in site suitability. This investigation underscores the complexity of translocation projects and emphasises the pivotal role of habitat quality in their outcomes. We advocate for detailed habitat assessments during the planning phase, avoidance of unstable habitats as translocation sites, and the implementation of long‐term monitoring practices.
... Introduction Reinforcement or 'restocking' programs are widely used in biodiversity conservation to sustain or restore declining or threatened populations (Fischer & Lindenmayer, 2000;Guy, Curnoe & Banks, 2013;Bubac et al., 2019). Reinforcement is defined as the intentional addition of captive-bred individuals or individuals from a stable wild population to an existing group of conspecifics, to recover endangered populations (Zlatanova, 2016). ...
... Reinforcement programs have been implemented worldwide on a variety of taxa, ranging from invertebrates to mammals (Soorae, 2018). Unfortunately, their success is often limited (Beck et al., 1994;Black et al., 1997;Fischer & Lindenmayer, 2000;Short, 2009). This is mainly due to the high short-term mortality of animals released during restocking programs McPhee & Silverman, 2004;Shier & Owings, 2007;Brichieri-Colombi & Moehrenschlager, 2016; Berger-Tal, Blumstein & Swaisgood, 2020). of the instinctive anti-predator behaviour when reared in captivity over many generations Fischer & Lindenmayer, 2000;. ...
... Unfortunately, their success is often limited (Beck et al., 1994;Black et al., 1997;Fischer & Lindenmayer, 2000;Short, 2009). This is mainly due to the high short-term mortality of animals released during restocking programs McPhee & Silverman, 2004;Shier & Owings, 2007;Brichieri-Colombi & Moehrenschlager, 2016; Berger-Tal, Blumstein & Swaisgood, 2020). of the instinctive anti-predator behaviour when reared in captivity over many generations Fischer & Lindenmayer, 2000;. ...
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The Common hamster (Cricetus cricetus) is one of the most endangered mammal in Europe. In Alsace, relict and fragmented populations persist. Population reinforcements have been implemented since the 2000s as an attempt to preserve the species. My thesis sought to identify solutions to improve these reinforcements by examining two main factors: an extrinsic one (a temporary pre-release in a semi-natural environment, known as soft-release) and an intrinsic one related to the age of hamsters at the time of release (adults and subadults). Main results of my work highlighted that a soft-release increased the reactivity of hamster females when facing predation risk, resulting in better survival after release compared to naïve females of the same age. This difference was noticeable for up to one month after release. Furthermore, female hamsters released into the wild 1.5 or 3 months after their birth in captivity had a similar survival rate and reproduction than one-year-old adult females. These findings can be used to inform conservation actions and improve the success of population reinforcements.
... Given the recognition of P. anta-nosy as an urgent candidate for conservation action (Raxworthy & Nussbaum 2000), an early 'Phelsuma antanosy Action Plan' (Randrianantoandro et al. 2012) was drawn up by local stakeholders including QMM, and translocation was proposed as a plausible conservation strategy. Translocation, or the intentional release of animals within their range in an attempt to augment a population, is increasingly being employed as a conservation tool in a variety of situations (Fischer & Lindenmayer 2000, Seddon 2010, with recent genomic evidence supporting its effectiveness (Capel et al. 2022). Yet, assessing the likely outcomes of translocation can be difficult (Weeks et al. 2011). ...
... Indeed, relocating individuals to unsuitable habitat has been identified as a reason for past failures in studies of translocation efficacy (Griffith et al. 1989). Past rates of success in reptile translocations have been low relative to other taxa (Dodd & Seigel 1991), though this disparity may be narrowing (Fischer and Lindenmayer 2000). In addition, the purpose behind a translocation has a strong effect on its outcome, with those motivated by conservation far more likely to succeed than those undertaken to mitigate humanwildlife conflict (Germano & Bishop 2009). ...
... Knowledge of habitat requirements aids the selection of suitable sites for translocation, in which environmental conditions are likely to facilitate subsequent survival and successful reproduction (Griffith et al. 1989). Past work on the efficacy of translocation projects has highlighted the role of release of translocated individuals into unsuitable habitat as a key cause of poor long-term outcomes (Griffith et al. 1989, Fischer & Lindenmayer 2000. Further, the quality of the release habitat for the species of concern is repeatedly shown to be the most important factor in reptile translocation success, yet conflictmitigation translocations often suffer from poor habitat suitability of release sites (Dodd & Seigel 1991, Germano & Bishop 2009. ...
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The Critically Endangered day gecko Phelsuma antanosy is micro-endemic to 2 humid forest sites in southeastern Madagascar. At one of these, Sainte Luce, it inhabits 4 forest fragments, 2 of which are set to be cleared for mining. Translocation of individuals from within the mining path to protected forest fragments has been proposed to mitigate the impact of habitat loss and the resulting reduction in population size. However, lack of knowledge of its habitat requirements and population structure inhibits efforts to evaluate the likely ecological consequences of translocation. We sampled 92 P. antanosy individuals across each of the known subpopulations in Sainte Luce and assessed the habitat conditions in which they occur, alongside levels of morphological variation. Using 5 morphological trait measures, we found no evidence of subpopulation differentiation. Almost all (>87%) P. antanosy individuals were found on Pandanus longistylus plants and occupancy levels were higher in areas with moderate (30-60%) canopy cover and no other Phelsuma spp. present, suggesting that translocated individuals should be located into these conditions and within a short (<5 m) distance of P. longistylus plants. We propose that siting individuals in patches meeting these criteria may help to maximise translocation efficacy. We discuss our results in the context of the lack of ecological and genetic information on this species, the general need for long-term monitoring of threatened species and the utility of translocation projects to inform and benefit conservation science.
... Translocating individuals has become an increasingly important conservation strategy for many threatened populations (IUCN/SSC, 2013), yet their post-release survival is often low (Fischer & Lindenmayer, 2000;Morris et al., 2021). Released animals need to learn to survive in the wild quickly and the failure to acquire necessary skills can lead to poor survival outcomes (Jule, Leaver, & Lea, 2008), thus hampering recovery efforts (Seddon, Armstrong, & Maloney, 2007). ...
... Released animals need to learn to survive in the wild quickly and the failure to acquire necessary skills can lead to poor survival outcomes (Jule, Leaver, & Lea, 2008), thus hampering recovery efforts (Seddon, Armstrong, & Maloney, 2007). While a number of variables can contribute to poor post-release survival, problems resulting from social behaviour have been identified as one of the key issues impacting translocation success (Berger-Tal, Blumstein, & Swaisgood, 2019), in part because the way animals interact can have carry-over consequences for other threats such as predation which has been documented to be a significant danger for many species (Fischer & Lindenmayer, 2000;White et al., 2012). For some species, successful integration into an existing group post-release has shown to be crucial for survival (Snyder et al., 1994), both for the safety provided by the group (Elgar, 1989) and learning important skills from wild conspecifics (Brakes et al., 2019). ...
... However, the migration survival probability of released captive-bred adults is reportedly very low (Smales et al., 2000;BirdLife Australia, 2020) making this group much less likely to survive their first migration compared to both juveniles and wild adults. This is surprising because the majority of captive-bred adults released in spring have already survived several months in the wild, yet few go on to successfully complete the migration (Smales et al., 2000;BirdLife Australia, 2020).The poor migration survival of released captive-bred adults is of conservation concern due to the extensive resources required to breed and release captive animals (Fischer & Lindenmayer, 2000). ...
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Reintroductions of threatened species is a conservation strategy utilised around the world. Unfortunately, many translocated individuals have poor rates of survival post‐release. If released individuals are unable to socially integrate into wild populations, they might lose the safety of the group or fail to learn critical skills. We examined the effects of age and captivity on sociality and migration survival for the critically endangered orange‐bellied parrot (Neophema chrysogaster). As part of recovery efforts, adult birds are released in spring to contribute to breeding and juveniles are released in autumn prior to migration. Historically, captive‐bred adults have low rates of migration survival, whereas captive and wild juveniles survive at comparable rates. We investigated both the long‐term impacts of captivity on sociality and how sociality impacted migration survival by constructing social networks and comparing captive and wild birds of different age classes. We found no differences between captive and wild birds, suggesting that released birds integrated into the population. However, juveniles were more strongly connected and demonstrated greater network stability than adults. While we found no impact of sociality on survival, our results provide evidence of different migration strategies previously described for juveniles and adults: adults depart in small groups and juveniles depart as a larger flock a few weeks later. We suggest that the low migration survival of captive‐bred adults may be attributable to this cohort missing the juvenile flocking phase. These results suggest that a juvenile developmental phase may be impactful in this species for future survival.
... Besides habitat restoration, predator control and the improvement of reproductive performance (Miskelly and Powlesland 2013;Johnson et al. 2018;Ewald, Sotherton, and Aebischer 2020), supplementation with individuals, captive-bred or wild-caught, is sometimes the last chance to avoid extinction (Armstrong and Seddon 2008;Miskelly and Powlesland 2013). Hence, translocations, the movement of individuals from one population to another (IUCN/SSC 2013) are an increasingly applied conservation strategy for recovering populations of endangered species (Fischer and Lindenmayer 2000;Berger-Tal, Blumstein, and Swaisgood 2020). ...
... However, conservation translocations are often cost-intensive projects that may not succeed from the perspective of population persistence (Taylor et al. 2017;Berger-Tal, Blumstein, and Swaisgood 2020). In most cases of failure, the original cause of decline has not been adequately addressed and eliminated before translocation (Fischer and Lindenmayer 2000;IUCN/SSC 2013). Habitat assessment is crucial, ensuring that site conditions and food availability meet the requirements of the species for long-term persistence (Armstrong and Seddon 2008;Johnson et al. 2018). ...
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Translocations are a conservation measure that is increasingly applied to assist the recovery of animal populations threatened with extinction. Long‐distance migrating passerines, however, have been rarely addressed in translocation projects so far. One such species is the globally threatened Aquatic Warbler Acrocephalus paludicola, a habitat specialist breeding in fen mires in Central Europe and wintering in sub‐Saharan Africa. The global breeding population has severely declined during the last decades due to habitat loss. Although the implementation of conservation measures has stopped the decline in the core breeding area, peripheral populations continue to decline. The aim of this pilot study was to reveal whether translocated Aquatic Warblers will return to a distant release site after wintering in Africa. Our translocation method is based on natal habitat imprinting of juvenile passerines before their first migration. In 2018 and 2019, 50 chicks (10–12 entire broods) each year were translocated 526 km from Belarus to Lithuania at an age of about 7 days and hand‐reared with predominantly wild insects captured in the surroundings of the release site. The survival rate of chicks until soft release from outdoor aviaries was 98% (49 fledglings released) in 2018 and 100% (50 fledglings released) in 2019. In 2019, 11 Aquatic Warblers (9 males, 2 females) were resighted at the release site after returning from wintering grounds. In 2020, nine birds (6 males, 3 females) were observed, including three males from the 2018 release cohort. An average apparent first‐year survival of 0.30 was estimated. The very successful outcome gives new impetus for the restoration prospects of declined populations of the Aquatic Warbler to halt extinction at the margins of the breeding range.
... Comparing outcomes of conservation translocations is inherently difficult due to the lack of clearly defined objectives and success indicators in many published studies and varying definitions of success among projects (Dodd & Seigel, 1991;Fischer & Lindenmayer, 2000;Seddon & Armstrong, 2016). Furthermore, failed translocations are often not published in peer-reviewed journals, creating the potential for bias toward more successful projects (Fischer & Lindenmayer, 2000;Germano & Bishop, 2009). ...
... Comparing outcomes of conservation translocations is inherently difficult due to the lack of clearly defined objectives and success indicators in many published studies and varying definitions of success among projects (Dodd & Seigel, 1991;Fischer & Lindenmayer, 2000;Seddon & Armstrong, 2016). Furthermore, failed translocations are often not published in peer-reviewed journals, creating the potential for bias toward more successful projects (Fischer & Lindenmayer, 2000;Germano & Bishop, 2009). Despite these challenges, a subset of the literature on conservation translocations is well-suited to comparative analyses. ...
Article
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Suites of coevolved traits related to reproduction and demography enable species to persist in the face of environmental change. In the case of biological invasions, the suite of life history traits, “life history strategies,” can be linked to successful establishment after an introduction. Conservation translocations share many similarities with biological invasions, yet studies examining the relationship between life history and translocation outcome are scarce. We collected data on key life history traits for all herpetofauna profiled in the IUCN Global Conservation Translocation Perspectives series to examine how life history can predict outcomes and difficulties of conservation translocations. For reptiles, our model showed that age at maturity showed a significant positive association with higher probabilities of more successful outcomes, while increased clutch/litter size and lifespan predicted less successful outcomes. We found no relationship between any life history trait and translocation outcome for amphibians. Our results showed that difficulties with conservation translocations are related more to phylogeny than life history. Amphibian translocations faced more difficulties due to the physical environment of release sites, but reptile translocations experienced more socio‐political difficulties. These relationships provide important insights for conservation practitioners that can be used in the feasibility and planning stages of translocations to anticipate and avoid challenges facing this complex and increasingly common form of conservation intervention.
... 27,28 The hunting interest for the red-legged partridge has developed both programs of reintroduction and environmental improvement, which has favored the resumption of land for cereal cultivation, as well as programmes of maintenance of meadows and pastures, managed by local hunting offices (hereafter, ATC: "Ambito Territoriale di Caccia") and Council Administrations. 22,29 On the other hand, programs of reintroduction have become an important conservation method to restore locally game species, 30,31 even if many reintroductions have been compromised by highly predation or breeding failure. 30,32,33 Some authors linked the failure of reintroduction to others factors such as genetic deterioration of the captive stock, 24,25,34 modifications of physiological and morphological characteristics 35 and changes in behavior. ...
... 22,29 On the other hand, programs of reintroduction have become an important conservation method to restore locally game species, 30,31 even if many reintroductions have been compromised by highly predation or breeding failure. 30,32,33 Some authors linked the failure of reintroduction to others factors such as genetic deterioration of the captive stock, 24,25,34 modifications of physiological and morphological characteristics 35 and changes in behavior. [36][37][38] Moreover, the habitat suitability plays a key role for successful species reintroduction 13,39,40 and breeding success. ...
Article
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Red-legged partridge restocking is a common practice in hunting management in Italy, as the species has become very uncommon in its native range, mostly following habitat loss. Therefore, habitat suitability plays a key role in the successful Reintroduction and especially in the breeding success of this game species. A landscape mosaic can affect the persistence and the reproductive success of partridges. We performed spring and summer censuses, in two consecutive years, to investigate the reproductive success and possibility to increase density of red-legged partridges in the province of Massa-Carrara, following programmes of sustainable habitat management and the creation of landscape mosaic.
... Unfortunately, despite increasing research, reintroduction programmes still have a low chance of success (Bubac et al., 2019), so it is important to understand the factors impacting reintroduction outcomes. Some of the key factors thought to increase the risk of failure include unsuitable habitat (Berger-Tal et al., 2020;Germano & Bishop, 2009;Wolf et al., 1996), not removing the initial cause of decline (Bubac et al., 2019;Fischer & Lindenmayer, 2000;Kleiman, 1989) and an insufficient number of individuals released (Fischer & Lindenmayer, 2000;Wolf et al., 1998). Reintroductions are generally more successful if the species is released within its historical range (Berger-Tal et al., 2020;Bubac et al., 2019;Griffith et al., 1989;Wolf et al., 1998). ...
... Unfortunately, despite increasing research, reintroduction programmes still have a low chance of success (Bubac et al., 2019), so it is important to understand the factors impacting reintroduction outcomes. Some of the key factors thought to increase the risk of failure include unsuitable habitat (Berger-Tal et al., 2020;Germano & Bishop, 2009;Wolf et al., 1996), not removing the initial cause of decline (Bubac et al., 2019;Fischer & Lindenmayer, 2000;Kleiman, 1989) and an insufficient number of individuals released (Fischer & Lindenmayer, 2000;Wolf et al., 1998). Reintroductions are generally more successful if the species is released within its historical range (Berger-Tal et al., 2020;Bubac et al., 2019;Griffith et al., 1989;Wolf et al., 1998). ...
Article
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Reintroductions are increasingly being used as a conservation tool to restore species to areas where they once existed. Unfortunately, many reintroduction projects fail to establish viable populations. Climate suitability at release sites is thought to be important in determining reintroduction outcomes, and future climate change is an essential consideration for effective reintroduction planning. Climate change threatens species in a variety of ways, such as by impacting life history traits or causing spatial and temporal distribution mismatches of interdependent species. Hibernating species, such as the hazel dormouse (Muscardinus avellanarius), may be particularly susceptible to changes in climate. For example, milder winters may increase the number of interbout arousals during hibernation, which are energetically costly. Timing of food availability may also be impacted by changing climates, potentially causing mismatches between activity and feeding opportunities. Here, we use species distribution models (SDMs) to map climate suitability for dormice in the UK. We also investigate the impact of climate suitability on a long‐running dormouse reintroduction programme, providing the first such investigation for a reintroduced mammal. We find that higher levels of current climate suitability increase the probability of reintroduction success. We find no effect of climate suitability on adult dormouse counts at reintroduction sites, but dormouse counts decline with time since reintroduction. Future projections predict that climate change may lead to more widespread climate suitability for dormice in the UK, reflecting predicted changes in seasonality, winter temperature and precipitation. Our work demonstrates the importance of understanding changing climate suitability for reintroduction planning, with potential widespread applications of SDMs for conservation projects of low‐dispersing mammals.
... Teixeira et al. 2007), detecting a self-sustaining population (e.g. Fischer & Lindenmayer 2000), or persistence of the translocated population for a defined period (Short 2010). However, if such definitions are applied to translocations of long-lived species with slow life histories (including many of New Zealand's endemic reptiles), the first signs of success may not be detectable for decades. ...
... Among several other key factors, the number of individuals released is a commonly reported driver behind translocation success or failure (Wren et al. 2023). There will be a threshold at which point the release cohort is too small to enable stages of translocation success, whether that is the result of the ease of finding breeding conspecifics or the effects of limited genetic diversity (Fischer & Lindenmayer 2000;Germano & Bishop 2009;Miller et al. 2009;Wren et al. 2023). These effects are particularly applicable to species with relatively small home ranges. ...
... Species translocations are a valuable and increasingly common conservation management tool used to reverse biodiversity loss through re-establishing, augmenting and/or expanding populations. Most translocations aim to establish viable populations at the release site (Fischer & Lindenmayer 2000) or permanently remove animals from the source site (Richard-Hansen et al. 2000). However, failures have been reported (e.g. ...
... However, failures have been reported (e.g. Linnell et al. 1997;Fischer & Lindenmayer 2000;Massei et al. 2010;Fontúrbel & Simonetti 2011). One such impediment to success is post-release hyper-dispersal, which is the long-distance movement of individuals post-translocation (any direction) rather than homing to their original location. ...
... For example, the reintroduction of wolves into Yellowstone National Park produced a series of cascading effects on major vertebrate species, but also on vegetation, effectively rewilding the Yellowstone area (Boyce 2018). Long-term monitoring and a higher effort in publishing the results of relocations are needed to improve our knowledge of the factors that affect the success of these projects (Fischer and Lindenmayer 2000). ...
... However, given the limited experimental evidence on the effectiveness of headstarting (Golba et al 2022), our knowledge of the benefits of this technique for E. orbicularis reintroduction is limited. The success of reintroductions is also highly variable (for an unsuccessful example see Bertolero and Oro 2009), but a large of number of founders is normally associated with successful projects (Fischer and Lindenmayer 2000). ...
Article
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Reintroduction programs can be an effective management tool for conservation of threatened chelonians, yet the success of such programs relies highly on numerous factors, such as the number of founders and the size of introduced individuals. We conducted a reintroduction experiment of the European pond turtle Emys orbicularis in a pond located within its historical range, using a small number of founders (N = 20), most of which were hatchlings maintained over winter and then released in June 2004 (mean weight about 33 g, head-started cohort, N = 7), and others were released within one month after hatching in October 2006 (mean weight about 8 g, control cohort, N = 8). One female contributed two hatchlings (out of seven) to the 2004 cohort and the eight hatchlings released in 2006, so most hatchlings were half siblings. Two adult males and three females from nearby recovery centres were also released in order to increase the genetic variability of the population. At the end of 2023, at least five founder individuals were alive and their weight was about 500 g. The growth rate was similar for both cohorts and is among the highest recorded for the species, suggesting that the habitat in the main pond is optimal. Based on Jolly-Seber and Manly-Parr estimates, reproduction within this population was confirmed by the increase to 42-44 individuals by 2023, respectively. Genetic analysis confirmed the expected low level of genetic diversity, the lowest for the subspecies E. o. occidentalis distributed across the Iberian Peninsula and northern Morocco.. For this population to thrive, a management plan with long-term monitoring is needed to maintain a favourable habitat and genetic diversity, and thus minimize the risk of extinction. Our findings suggest that a small number of E. orbicularis hatchlings can be used as founders to successfully reintroduce the species in suitable habitats, even without headstarting.
... Conservation translocations (hereafter, translocations) benefit species at imminent risk of decline and extinction by moving organisms from one location to another, and include reintroductions (e.g., into the historical range from which a species has been extirpated) and (or) as reinforcements (e.g., to augment extant populations, IUCN/SSC, 2013; Seddon et al., 2014). Translocations generally require a high degree of conservation effort (e.g., time and resources, Fischer and Lindenmayer, 2000), involve a high degree of uncertainty, and result in varying degrees of success (Griffith et al., 1989;Fischer and Lindenmayer, 2000). Translocation program success is often difficult to measure because this assessment requires long-term data and standardized criteria success, both of which are often lacking (Morris et al., 2021;Marino et al., 2024). ...
... Conservation translocations (hereafter, translocations) benefit species at imminent risk of decline and extinction by moving organisms from one location to another, and include reintroductions (e.g., into the historical range from which a species has been extirpated) and (or) as reinforcements (e.g., to augment extant populations, IUCN/SSC, 2013; Seddon et al., 2014). Translocations generally require a high degree of conservation effort (e.g., time and resources, Fischer and Lindenmayer, 2000), involve a high degree of uncertainty, and result in varying degrees of success (Griffith et al., 1989;Fischer and Lindenmayer, 2000). Translocation program success is often difficult to measure because this assessment requires long-term data and standardized criteria success, both of which are often lacking (Morris et al., 2021;Marino et al., 2024). ...
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Translocation of captive-bred animals is a widely used conservation strategy to support the recovery of imperiled wild populations. Identifying which factors enhance or limit survival after release can be important in adapting translocation strategies, particularly for species with low survival rates after release from captivity. Many translocation programs track post-translocation survival, but few complete spatial-statistical assessments of mortality risk associated with release environments. Typically, few animals are released from captive breeding programs, limiting the sample size available for analyses. We aimed to create a workflow that used limited datasets to evaluate the influence of spatial conditions and other factors on mortality risk. Greater sage-grouse ( Centrocercus urophasianus ) are endangered in Canada and of conservation concern throughout their range in the United States. After the species declined precipitously in Canada, a captive breeding program was initiated with subsequent releases in Alberta and Saskatchewan. Despite success in captive breeding, mortality rates of released sage-grouse were high. We used GPS- and VHF-based locations of released sage-grouse to determine how spatial features influence mortality risk of sage-grouse after release from captivity. We implemented a multistep approach to quantify and map risk relative to the environmental features associated with mortality. We also assessed whether the movement behaviors of sage-grouse correspond with environmental risk factors by using a combination of survival models and integrated step-selection functions. Mortality of sage-grouse in Alberta was hastened in areas close to anthropogenic disturbance. Although birds in Alberta avoided areas of higher mortality risk, those in Saskatchewan did not, perhaps due to environmental and selection constraints. This multistep approach allowed us to utilize small sample sizes to assess key risk factors in the landscape. This process supports the adaptive modification of translocation plans and can similarly support other data-limited scientists and managers in assessing environmental mortality risk and defining conservation actions for endangered species.
... Reintroduction attempts often fail to result in the establishment of viable populations for numerous reasons [14,17]. Translocations cause unintended consequences to the animal, including behavioral changes, reproductive dysfunctions [18], predator naivety [19], and the inability to locate suitable food or shelter [20]. ...
... The low success of reintroduction programs has led to the advancement of many novel techniques that seek to improve the survival and reproduction of translocated individuals. Previous studies suggest several crucial improvements for wildlife relocations, including the need for more rigorous testing to assess the appropriateness of the approach, the establishment of criteria to evaluate relocation a success or failure, comprehensive post-relocation monitoring, financial accountability to ensure responsible resource allocation, and increased transparency in publishing results [17,21]. In the realm of habitat restoration, a study reports four pivotal elements: identifying and securing suitable areas, restoring indigenous vegetation before translocation, and implementing long-term habitat management to prevent elevated mortality or dispersal [22]. ...
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Homing is often a critical aspect of an animal’s behavioural and spatial ecology. Translocation is considered to be a wildlife management strategy that could reduce human-wildlife confrontation, but this strategy may not be effective if animals attempt to home to their original capture location. Translocation of animals from sites where possible human-wildlife interaction occurs is a widespread but controversial intervention to resolve conflicts. In India, snakes are often the subject of such translocations, but there is a paucity of information on the behaviour of translocated snakes compared to resident snakes. The Indian python (Python molurus), one of the largest carnivores in the Indian subcontinent, is classified as Near Threatened by the IUCN. We conducted a two-year radio-tracking study (December 2018 to December 2020) on the movements of 14 adult Indian pythons in the Moyar River Valley, within the Sathyamangalam and Mudumalai Tiger Reserves. Eleven of the 14 pythons were translocated 0.28 -55.7 kms from their capture locations, while 3 pythons were not translocated: 6 were translocated short distances (<5km from capture; range 0.28 - 4.67 kms), 2 were translocated to medium distances (9-11 kms from capture location), and 3 were translocated to long distances (21 – 55.7 kms from capture location). Four of the six snakes translocated short distances all returned to within 500m of their original capture locations, and all 6 returned over 60% of the translocated distance to the initial capture location. Of the two snakes translocated medium distances, both returned to within 1.1km of the capture location (∼90% of the distance home). None of the three snakes that were translocated long distances successfully returned to their capture locations. Translocated pythons exhibited greater net movement distances than resident snakes within the first 2 months of release. Based on these results, long-distance translocation may be an effective strategy to minimize human-python conflict, while short or medium distance translocation is unlikely to be successful. However, more research is needed about the long-term survival of translocated snakes as well as soft-release methodologies that could prevent aberrant movement behaviour directly following release.
... However, there are often many environmental unknowns that can hinder the success of translocation efforts, even after careful consideration of potential risks. As a result, translocations may fail due to unexpected factors, such as unknown criteria for suitable habitat, especially if the species is reintroduced outside of their historic range (Fischer and Lindenmayer, 2000;Stadtmann and Seddon, 2018). This is especially apparent at the beginning of restoration initiatives that work with species and sites with unknown risks (e.g., see outcomes of mussel translocations reported in De Paoli et al., 2015;Wilcox et al., 2018;Alder et al., 2020). ...
... Predators in the recipient environment often pose one of the biggest limitations to the success of species translocations by consuming newly translocated individuals (hereafter founders; Fischer and Lindenmayer, 2000;Moseby et al., 2015;Robinson et al., 2020). Managing the risk of predation to founders can be difficult, but addressing this early in the translocation process can yield successful outcomes (e.g., see approaches to predation risk management in Robinson et al., 2020). ...
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The assessment of site suitability is a crucial step for informing future successful species reintroductions. It ensures that translocated species have the highest chance of survival in their new environment while minimising ecological risks. However, it can be challenging when risk factors are unknown, especially when working with sessile species that cannot easily relocate to more favourable conditions. Under these scenarios, rapid (1-2 week-long), small-scale (< 1 m²) experimental translocations can help reduce uncertainty and improve restoration outcomes. This study conducted small-scale experimental translocations of green-lipped mussels, Perna canaliculus, to 11 shallow coastal sites spread across Tīkapa Moana/the Hauraki Gulf, Aotearoa/New Zealand to investigate the relationship between predator abundance, environmental factors, and mussel loss to help refine existing site selection criteria. The total number of known mussel predators counted from timelapse images was used as a proxy for potential predator pressure. Translocated mussel survival ranged from 10 - 99% and was best predicted by current speed, wind direction, predator abundance, water clarity, and depth (adjusted R² = 0.505). Predator abundance was best explained by site location (p = 0.001) and had weak correlations among environmental parameters (Rho = 0.067). These results suggest that small, short-term (1-2 week) experimental translocations can help to refine site selection criteria and reduce uncertainty in the site-selection process for larger-scale shellfish reintroduction efforts with unknown and/or hard-to-control risk factors.
... Translocation of individuals within their historical range is one of the most common actions employed for augmenting an existing population to increase size, stabilize demographic rates, or increase genetic diversity for genetic rescue and to reestablish extirpated populations (Gaywood & Stanley-Price, 2023;IUCN SSC, 2013). Translocations are often utilized under threat of extirpation (Brichieri-Colombi & Moehrenschlager, 2016;Seddon et al., 2007), can be logistically difficult and expensive to implement (Berger-Tal et al., 2020;Fischer & Lindenmayer, 2000;Wolf et al., 1996), and are often conducted with limited resources for monitoring (Berger-Tal et al., 2020;Griffith et al., 1989). Changes in population size, demographic rates, range size, and genetic composition can be used to assess translocation performance (Dalrymple & Bellis, 2023). ...
... Augmentation outcomes have been highly variable among wildlife species for myriad interacting reasons (Berger-Tal et al., 2020;Fischer & Lindenmayer, 2000;Griffith et al., 1989;Wolf et al., 1996). The potential role of local adaptation among source and recipient populations is an infrequently explored Hohenlohe et al., 2021;Seaborn et al., 2021) component of augmentation that becomes more accessible as technology advances (Andrews et al., 2016;Hohenlohe et al., 2018;Oyler-McCance et al., 2020). ...
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Conservation translocations are an important conservation tool commonly employed to augment declining or reestablish extirpated populations. One goal of augmentation is to increase genetic diversity and reduce the risk of inbreeding depression (i.e., genetic rescue). However, introducing individuals from significantly diverged populations risks disrupting coadapted traits and reducing local fitness (i.e., outbreeding depression). Genetic data are increasingly more accessible for wildlife species and can provide unique insight regarding the presence and retention of introduced genetic variation from augmentation as an indicator of effectiveness and adaptive similarity as an indicator of source and recipient population suitability. We used 2 genetic data sets to evaluate augmentation of isolated populations of greater sage‐grouse (Centrocercus urophasianus) in the northwestern region of the species range (Washington, USA) and to retrospectively evaluate adaptive divergence among source and recipient populations. We developed 2 statistical models for microsatellite data to evaluate augmentation outcomes. We used one model to predict genetic diversity after augmentation and compared these predictions with observations of genetic change. We used the second model to quantify the amount of observed reproduction attributed to transplants (proof of population integration). We also characterized genome‐wide adaptive divergence among source and recipient populations. Observed genetic diversity (HO = 0.65) was higher in the recipient population than predicted had no augmentation occurred (HO = 0.58) but less than what was predicted by our model (HO = 0.75). The amount of shared genetic variation between the 2 geographically isolated resident populations increased, which is evidence of periodic gene flow previously assumed to be rare. Among candidate adaptive genes associated with elevated fixation index (FST) (143 genes) or local environmental variables (97 and 157 genes for each genotype–environment association method, respectively), we found clusters of genes with related functions that may influence the ability of transplants to use local resources and navigate unfamiliar environments and their reproductive potential, all possible reasons for low genetic retention from augmentation.
... Furthermore, small estimates of effective population sizes for lochs Lomond and Eck suggest limited capacity to adapt to future environmental change and, perhaps even more limited capacity for their refuge populations. The rigorous evaluations of these translocation efforts revealed the importance of avoiding founder effects by seeking to translocate relatively large numbers (e.g., >100) of genetically representative animals (Fischer and Lindenmayer, 2000) to not only maximize survival but also to prevent bottlenecks and founder effects in the refuge populations. ...
... We found two other case studies where a coregonine fishery was closed in response to low population abundance. The first was the C. albula fishery in the Estonian waters of Lake Peipsi (58.667, 27.296) from 2000(Kangur et al., 2020. When environmental conditions improved, a lower level of harvest was resumed but the population is still low enough that it is subject to future closures to sustain the population (K. ...
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Over the past centuries, coregonines have been exposed to a range of stressors that have led to extinctions, extirpations, and speciation reversals. Given that some populations remain at risk and fishery managers have begun restoring coregonines where they have been extirpated, we reviewed the primary and gray literature to describe the diversity of coregonine restoration or conservation actions that have been previously used. Although stocking of hatchery-reared fish has been commonly used for supplementing existing coregonine fisheries, we considered stocking efforts only with specifically conservation or restoration goals. Likewise, conservation-driven efforts of translocation were not widespread, except in the United Kingdom for the creation of refuge populations to supplement the distribution of declining stocks. Habitat restoration efforts have occurred more broadly and have included improving spawning habitat, connectivity, or nutrient concentrations. Although harvest regulations are commonly used to regulate coregonine fisheries, we found fewer examples of the creation of protected areas or outright closures. Finally, interactions with invasive species can be a considerable stressor, yet we found relatively few examples of invasive species control undertaken for the direct benefit of coregonines. In conclusion, our review of the literature and prior Coregonid symposia revealed relatively limited direct emphasis on coregonine conservation or restoration relative to more traditional fishery approaches ( e.g. , supplementation of fisheries, stock assessment) or studying life history and genetics. Ideally, by providing this broad review of conservation and restoration strategies, future management efforts will benefit from learning about a greater diversity of potential actions that could be locally applied.
... Efforts to restore ecosystem function are now commonplace (Fischer and Lindenmayer, 2000;Morandini and Ferrer, 2017;Seddon et al., 2007); however, other concerns can result from the re-establishment process including unforeseen interactions (Laves et al., 1999;Lewis et al., 2009;Swaisgood et al., 2019). The redcockaded woodpecker (RCW; Dryobates borealis) is a federally threatened species endemic to pine forests of the southeast United States and has been reintroduced to many parts of its former range (Carrie et al., 1999;Saenz et al., 2002;US Fish and Wildlife Service [USFWS], 2003). ...
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Southern flying squirrels (Glaucomys volans) occupy and destroy the nests of the endangered red‐cockaded woodpecker (RCW; Dryobates borealis), yet few studies have assessed habitat use within and outside of forest partitions managed for RCW cavities (“cluster partition”). We estimated flying squirrel densities of 0.23 squirrels/ha (95% CI: 0.21–0.26). Little to no evidence of differences was found between flying squirrel home range sizes nor the relative importance value of mast trees within home ranges (P > 0.05) despite vegetation differences between areas inside and outside of cluster partitions (P ≤ 0.01). The lack of evidence may be due to large nightly movements allowing home ranges to overlap cluster partitions and surrounding hardwood habitats. Future management efforts to reduce flying squirrel and RCW interactions should consider multiple strategies including hardwood reduction near cluster partitions and cavity supplementation.
... Animal translocations for conservation efforts include the transfer or release of animals, which aim to improve the conservation status of species locally and globally and restore ecosystem functions in a location [3]. Reintroduction has long been used in conservation efforts for various wildlife species to establish stable populations in their natural habitats [4,5]. Animals released into the wild may come from rehabilitation and captive breeding in conservation facilities [6]. ...
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One of the conservation efforts for the Komodo Dragon (Varanus komodoensis) is the translocation of the Komodo. Six juvenile captive-bred Komodo Dragons were translocated from Bogor to Wae Wuul Nature Reserve, East Nusa Tenggara Province, on 23rd September 2023. This research aims to calculate and describe home ranges total daily movements and the habitat conditions of Komodo Dragons. The research was carried out at the Wae Wuul Nature Reserve using the radio tracking method for 11 days, as most of the translocated Komodo Dragons could only survive in the short term. Results showed that translocated Komodo Dragons tend to stay near the initial release location. The average total daily movement translocated Komodo Dragons was 424.53 m day–1 with an average home range of 34.11 ha and an average core area of 8.20 ha. The habitats used by Komodo Dragons are savanna and monsoon forests dominated by bushes and trees. The presence of feral dogs and vehicle road access have the potential to pose a threat to the translocated Komodo Dragons.
... Animal translocations for conservation efforts include the transfer or release of animals, which aim to improve the conservation status of species locally and globally and restore ecosystem functions in a location [3]. Reintroduction has long been used in conservation efforts for various wildlife species to establish stable populations in their natural habitats [4,5]. Animals released into the wild may come from rehabilitation and captive breeding in conservation facilities [6]. ...
Article
Full-text available
One of the conservation efforts for the Komodo Dragon (Varanus komodoensis) is the translocation of the Komodo. Six juvenile captive-bred Komodo Dragons were translocated from Bogor to Wae Wuul Nature Reserve, East Nusa Tenggara Province, on 23 rd September 2023. This research aims to calculate and describe home ranges total daily movements and the habitat conditions of Komodo Dragons. The research was carried out at the Wae Wuul Nature Reserve using the radio tracking method for 11 days, as most of the translocated Komodo Dragons could only survive in the short term. Results showed that translocated Komodo Dragons tend to stay near the initial release location. The average total daily movement translocated Komodo Dragons was 424.53 m day-1 with an average home range of 34.11 ha and an average core area of 8.20 ha. The habitats used by Komodo Dragons are savanna and monsoon forests dominated by bushes and trees. The presence of feral dogs and vehicle road access have the potential to pose a threat to the translocated Komodo Dragons.
... It is premature to conclude on long-term viability after one year, but the results strongly support that the ongoing restoration efforts on this island have been successful in improving habitat quality. To ensure a successful reinforcement, the cause of the initial decline has to be eliminated (Fischer & Lindenmayer, 2000), and removal of shrub and tree overgrowth seems key to maintain population viability of the chequered blue butterfly (Marttila et al., 2000). ...
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Many Lepidoptera species are declining to the point that active measures such as reinforcements and reintroductions are necessary to maintain viable populations. To maximise success of such efforts, we need to understand the factors influencing habitat preferences for oviposition. In a Swedish island population of the red‐listed chequered blue butterfly (Scolitantides orion), we characterised oviposition preference by documenting whether the presence and abundance of eggs (i) increased with size and local density of its host plant, orpine (Hylotelephium telephium), and (ii) was associated with nectar plant abundance, degree of shading, and ground cover composition within small and large circular plots (1 m vs. 5 m radius) around focal plants. To reinforce a tiny population on a neighbouring island, we released 127 pupae and 46 imagos and recorded oviposition for two seasons. The probability of receiving eggs increased with focal host plant size, and also with mean size of other host plants and cover of lichens within the large plots. The abundance of eggs within large plots increased with host plant density and amount of lichen cover. Habitat characteristics of the large plots predicted oviposition better than did those of small plots, and both outperformed models including host plant size only. In the reinforcement population, all released pupae eclosed, and we found a total of 507 eggs on 272 host plants during the release season. Eggs were present on 5% of examined host plants, and median distance to a release spot was 19.3 m. In the following year, we found 420 eggs on 209 plants, and median distance to a release spot increased to 35.7 m, indicating diffusion through the habitat. Practical implication. The chequered blue butterfly prefers to oviposit on large host plants in patches with high host density and high cover of lichens. To identify suitable release habitats, environmental conditions should be considered in an area of ca 80 m². The reinforcement shows that small releases can be successful and suggests that similar low‐effort approaches can be effective to boost local populations of many threatened butterflies, provided suitable habitats are available.
... The second lesson is to consider how best to balance investment in the reintroduction of zoo-bred animals against attempting to boost breeding productivity of the remaining wild population through nest protection. Zoobreeding and release is a central component of many threatened species recovery programs (Conde et al. 2011), but such programs are expensive to run (Fischer and Lindenmayer 2000) and can lead to the release of animals that are less fit for survival in the wild than their wild-born counterparts . Whilst zoobred Regent Honeyeaters can survive in the wild, there is currently little evidence that zoo-bred birds are contributing substantially to the recruitment of juveniles to the wild population through successful breeding (Tripovich et al. 2021). ...
Article
Nomadic species are challenging to conserve, because their high mobility and irregular settlement patterns make it difficult to implement targeted conservation actions. Here, we report on the first sustained attempt to protect nests of Critically Endangered Regent Honeyeaters from predation and to release zoo-bred birds into a wild breeding event. During the 2023 breeding season, targeted culling of known nest predator species within the area of 10-12 wild breeding pairs within Capertee National Park was associated with a daily nest survival rate of 97.9%. This equated to an overall nest success rate of 48.6% and resulted in the fledging of 18 juveniles from nine nests-double the average nest success rate from 2015, 2016 and 2017 (24.1%) when Regent Honeyeaters bred in the same location. Population viability analysis indicates nest protection alone could slow the rate of population decline, but its effectiveness depends on the proportion of nests that can be located and protected each year. Fourteen zoo-bred Regent Honeyeaters were released approximately half way through the breeding event. Seven zoo-bred birds were confirmed alive 5 weeks post-release, but no zoo-bred birds released in 2023 attempted to breed in this year. Although our sample is small and prone to stochastic effects, we provide non-experimental evidence that nest predator management can play a key role in boosting recruitment of juvenile Regent Honeyeaters to the wild population. In combination with the reintroduction of zoo-bred birds and habitat restoration, nest predator management can help prevent imminent extinction of the Regent Honeyeater. ARTICLE HISTORY
... A recent review of published field studies found that release success increased up to about 20-50 individuals butparadoxicallydeclined slightly above several hundred individuals (Morris et al., 2021). In practice, in many reintroductions of vertebrates, adult animals especially breeding femalesare preferred because this demographic component is most likely to survive and contribute to population growth (Fischer and Lindenmayer, 2000;Seddon et al., 2007). Further considerations when selecting animals to translocate to a rewilding site include ensuring, as far as possible, that individuals are not closely related and collectively have at least moderate levels of genetic diversity and are healthy and free of parasites or pathogens that could otherwise compromise individual welfare and population growth (Dunlop and Watson, 2022). ...
Chapter
Rewilding is the deliberate (re)introduction of animal species into local or regional areas with the joint aims to assist the conservation of those species and promote the re-establishment of lost or degraded ecological processes. In Australia and Aotearoa New Zealand rewilding is particularly important in reversing losses of species and ecological processes that are among the most severe in the world. This chapter outlines the benefits and the challenges of rewilding in Australia and New Zealand, noting that much successful rewilding occurs in places where invasive species have been removed. Four case studies are presented. The first two describe rewildings on formerly degraded agricultural land (Tiritiri Matangi Island, Scotia Sanctuary), while the third posits a conceptual rewilding program using a continental top predator, the dingo. The fourth case study describes a digitally-enabled survey and monitoring system on a mixed-agriculture farm that provides a step towards rewilding such landscapes in future.
... Conservation translocations and reintroductions are inherently complex, high-risk activities, and reviews of their outcomes have typically reported low rates of success (Wolf et al., 1996, Fischer & Lindenmayer, 2000, Seddon, 2010, Sainsbury & Vaughan-Higgins, 2012, Weise et al., 2014, Berger-Tal et al., 2020. Nonetheless, in circumstances where natural recovery or recolonization is unlikely, translocations may be necessary to re-establish a species following extirpation, ensure population viability and restore or expand geographic distribution. ...
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The successful onset of recovery of the European pine marten (Martes martes) in some parts of Britain through range expansion and, more recently translocation for reintroductions, has resulted in a strong interest in reintroduction projects throughout the country. However, the geographic scope and conservation goals of these initiatives are often local and lack consideration of how they fit within the wider context of national-scale pine marten conservation. Here, we aim to maximize conservation benefit strategically at a national level by developing a simple, transparent, and transferable framework based on landscape modelling methods and spatially explicit population viability analyses. Our new methodology has been developed specifically to inform decisions involving the spatial targeting of pine marten conservation measures. We began by applying habitat suitability and connectivity modelling at a national scale. Then, we performed spatially explicit life history simulations to assess the natural recovery of the species. This information was used to identify regions of interest for future reintroductions, and we performed subsequent simulations to assess the viability of a reintroduced population within each region. From all the regions assessed, we identified two that should be prioritized for further consideration based on our analyses of habitat suitability, connectivity and the viability of reintroduced populations. While our framework can be used to identify and prioritize regions of conservation value generally, our focus here is on the biological considerations associated with identifying suitable landscapes for pine marten reintroduction.
... Despite the above examples of successful reintroductions, an assessment of historic global reintroduction efforts thus far shows that many wildlife reintroductions do not result in survival and reproduction of the released animals, much less establishment of self-sustaining populations (Fischer & Lindenmayer, 2000;Jule et al., 2008;Stepkovitch et al., 2022). Carnivore reintroductions specifically can face challenges from carnivores' ecological needs for large amounts of prey and habitat Wolf & Ripple, 2016) plus their often-slow life histories (Stier et al., 2016). ...
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Reintroductions are often needed to recover carnivore populations and restore ecological processes. Felids are common subjects of reintroduction efforts, but published population models informing felid reintroduction plans are uncommon, and poor planning has sometimes caused issues in felid reintroduction programs. In the United States, ocelots (Leopardus pardalis pardalis) are classified as endangered, and recovery requires population expansion into historic habitat. A multi‐organization effort is underway to establish a new ocelot population in Texas by releasing ocelots into an area of 478 km² of suitable habitat in ocelots' historic but now unoccupied range. In this study, we used population viability analyses to compare different ocelot reintroduction strategies for the identified reintroduction area. Based on a potential ocelot breeding program's limitations, we modeled reintroduction using a founding population of no more than six ocelots and no more than four ocelots released per year for no more than 15 subsequent years. Within these limitations, we assessed projected population abundances and extinction risks after 30 years for 20 different reintroduction strategies. We found that long‐term releases are necessary to establish a viable population; under conservative model assumptions, releasing six ocelots in the initial year and then releasing four individuals annually for an additional 10–15 years is necessary for attaining a projected population greater than 36.62 ocelots (baseline) with <6% extinction risk. We also found that ocelot population abundance is about equally sensitive to post‐release mortality and inbreeding depression. This highlights the importance of not only supporting reintroduced ocelots' survival but also managing for high genetic diversity in the reintroduction program. Further, we found that realistic but more liberal assumptions on the carrying capacity of the reintroduction area and the age of first reproduction for ocelots increase projected population abundances (53.95 individuals and 61.26 individuals, respectively), and thus reintroduction success. The model's sensitivity to carrying capacity suggests that long‐term habitat protection and expansion are among the most important management actions to support ocelot reintroduction. Our study establishes the first population viability model for an ocelot reintroduction plan anywhere across the species' wide geographic range, and it reinforces several key considerations for wildlife reintroduction efforts worldwide.
... text. Moreover, many reintroduced populations fail to successfully establish themselves, with fewer than half of historical reintroductions of those threatened or endangered species resulting in established populations (Fischer & Lindenmayer, 2000;Griffith et al., 1989). As ecoregions continue to shift due to climate change, attempts to maintain historical ecological baselines are increasingly difficult and, in some cases, may be counterproductive (Schlaepfer et al., 2011). ...
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For centuries, humans have intentionally moved species around the world, and such actions have rarely been laudable from conservation perspectives. The notion that introduced populations of cold‐adapted species hold conservation value despite their non‐native status remains controversial. Many such populations exist as a legacy of humans moving wildlife to novel environments with little true consideration of species conservation. Herein, we identify cases in which individuals from inadvertent climate refugia (ICR) are returned to formerly occupied ranges or used to augment declining native populations. While conservation benefits have been infrequently realized, the global distribution of ICR offers a potentially untapped resource. Lessening biodiversity loss under increasing climate challenges will likely require assisted migration of many species and necessitate novel valuation of extant introduced populations—such as those within ICR. While ecological costs of translocated species are widely known, we highlight how species moved generations ago to ICR offer a reservoir for reintroductions and a buffer against rapidly changing climates.
... Numerous reintroduction projects involving endangered species have been implemented worldwide, including those involving red deer (Cervus canadensis) (Guo et al., 2022), Javanian bison (Bos javanicus) (Chaiyarat et al., 2020), black bears (Ursus thibetanus) (Clark et al., 2002), and giant pandas (Ailuropoda melanoleuca) (Shan et al., 2014;Yang et al., 2018). However, the average success rate of these reintroductions remains low, indicating a need for further research and analysis to improve outcomes (Dallas & Warne, 2023;Fischer & Lindenmayer, 2000;Seddon et al., 2012;Tang et al., 2020). One contributing factor to these low success rates may be conditions associated with captivity: limited space to move around, high population densities, and suboptimal hygiene can lead to increased levels of pathogenic bacteria in the gut microbiota of captive animals, potentially compromising their health and adaptability upon release (Kedia et al., 2021;Lecorps et al., 2021;Li, Hu, et al., 2018;Mosca et al., 2016). ...
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Prey populations significantly influence the distribution of top predators. The sika deer (Cervus nippon), a key prey species for the Amur tiger in Northeast China, plays a critical role in the recovery and dispersal of Amur tiger populations. Reintroduction is a pivotal strategy for restoring prey populations, but it presents challenges, especially in terms of adaptation to the natural environment during the natural training process before animals are released. In this study, we sampled six adult and six sub‐adult sika deer and employed high‐throughput sequencing of the 16S ribosomal RNA gene to investigate changes in gut microbial diversity, composition, and function during natural training. The results showed that adult sika deer had higher gut microbiota diversity compared to sub‐adults. However, as natural training progressed, the gut microbial diversity in sub‐adults approached that of adults. Additionally, beneficial, fiber‐digesting bacteria associated with adaptation to the natural environment tended to increase during nature training in both adult and sub‐adult sika deer, while pathogenic bacteria tended to decrease. We also compared the metabolic function of the gut microbiota in adult and sub‐adult sika deer, which showed that the carbohydrate metabolic function of both adults and sub‐adults decreased significantly with natural training, declining more rapidly in sub‐adults. Conversely, the lipid metabolic function in sub‐adults increased significantly with natural training. Overall, a period of nature training is necessary before reintroducing animals to their natural habitats, and sub‐adult sika deer, in particular, exhibit greater adaptability to environmental changes as reflected by their gut microbiota dynamics. These findings offer valuable insights for the reintroduction of sika deer and other ungulates. We recommend incorporating natural training in reintroduction programs and prioritizing sub‐adult animals for reintroduction.
... Species translocations have contributed to major conservation successes, such as the recovery of the declining populations of the large blue butterfly Maculinea arion in the United Kingdom (Thomas, Simcox, and Clarke 2009). However, many animal species often fail to establish viable populations in new areas after reintroduction attempts (Fischer and Lindenmayer 2000) because environmental conditions, notably climatic conditions, are unsuitable for the target species at the recipient site (Bellis et al. 2020). Trait and phylogenetic-based studies might be useful to increase our understanding of species-environment matching (Balazs et al. 2020). ...
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Aim: The relative importance of traits and phylogeny to predict species extinction risk is unclear and it depends on which traits are measured and their phylogenetic conservatism. Here, we evaluate the power of functional traits, ecological characteristics, such as range size and specialization, and phylogeny to predict climatic risks in European butterflies. Location: Europe. Time Period: Distribution data from 1981 to 2002 was used to project range shifts up to 2080. Major Taxa Studied: In total, 268 European butterfly species (Rhopalocera). Methods: We extracted information on climatic risk for each species from the literature. Two hypothetical conditions were assumed: full climate tracking and no climate tracking. We used variation partitioning to quantify and disentangle the effects of phylogeny, four traits (wingspan, voltinism, overwintering and egg volume) and two ecological characteristics (range size and specialization) on climatic risk. We used Random Forest as an imputation method to predict climatic risk values for additional European butterfly species that have not been previously modelled. Results: Range size and degree of specialization strongly predicted climatic risk of European butterflies, but only for no climate tracking scenarios. Overall, more generalist species have larger ranges and are less vulnerable to climate change. Furthermore, we found that phylogenetic information adds strong power to explain climatic risk, especially, but not exclusively for scenarios that assume full climate tracking. Main Conclusions: Considering current scenarios of habitat fragmentation in Europe, it is likely that species with smaller ranges and high degree of specialization will be unable to track their climates and thus be more at risk. However, our results imply that assisting dispersal and colonization might allow small ranged species to cope with climate change. Our analysis also indicate that phylogeny can be used as a proxy of unmeasured traits to predict climatic risk under certain circumstances.
... However, many studies fail to do one or more of these things, which limits our ability to generate empirically based recommendations to inform future translocation projects. Even when clear goals are set, many translocation studies do not produce desired outcomes for reasons including predation of translocated animals, unexpected dispersal, disease, and unsuitable management of habitat or populations (Bennett et al., 2012;Carrlson et al., 2014;Destro et al., 2018;Fischer & Lindenmayer, 2000;Letty et al., 2007). The fragmentation of literature across multiple disciplines also may hinder the development of unifying recommendations in reintroduction biology (Seddon et al., 2007). ...
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The success of avian translocations depends on many factors. Release age is often cited as an influential factor that warrants further study, yet no general guidelines exist to improve the outcome of translocations. We conducted a systematic review of literature on captive‐reared or wild‐caught birds that incorporated >1 age class in their analyses of post‐release survival, dispersal, or reproduction. Fifty‐two studies met our search criteria, and 39 were retained for an evaluation of post‐release survival. For studies reporting at least one trend, more reported higher post‐release survival when birds were translocated at younger ages (68%) than at older ages (32%). This pattern was most pronounced for wild‐caught birds and for captive‐reared birds released within their first year of life. Captive‐reared birds of prey were an exception, with birds released at older ages often having higher survival than birds released at younger ages. We review the authors' hypotheses for why birds released at younger ages are more likely to settle, survive, and breed. More research is needed on the potential effects of release age on dispersal and reproduction. We recommend that future studies incorporate age of release as a covariate and control for the effect of season of release in experiments.
... Common criticisms include a lack of clear program objectives, poor follow-up monitoring, concerns that translocations do not address, and may even legitimise, the processes that drive local extinctions (e.g., habitat loss), and fears of outbreeding depression caused by the movement of individuals between genetically dissimilar populations (i.e., genetic rescue) (Dresser et al., 2017;Fischer & Lindenmayer, 2000;Germano et al., 2015). Fortunately, there is a growing body of evidence that the risks of outbreeding depression are often exaggerated, and that any negative consequences will typically only persist for a few generations, if they manifest at all (Frankham, 2015;Ralls et al., 2020 where possible, with the understanding that precautions must also be taken to reduce the possibility of negative non-genetic effects caused by the introduction of pathogens (Dalziel et al., 2017;Kock et al., 2010;Woodford & Rossiter, 1993) or the modification of existing host-parasite dynamics (Aiello et al., 2014;Dunlop & Watson, 2022;Lott et al., 2012Lott et al., , 2018Lott, Hose, et al., 2015;Lott, Isberg, et al., 2015). ...
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Genetic management is a critical component of threatened species conservation. Understanding spatial patterns of genetic diversity is essential for evaluating the resilience of fragmented populations to accelerating anthropogenic threats. Nowhere is this more relevant than on the Australian continent, which is experiencing an ongoing loss of biodiversity that exceeds any other developed nation. Using a proprietary genome complexity reduction‐based method (DArTSeq), we generated a data set of 3239 high quality Single Nucleotide Polymorphisms (SNPs) to investigate spatial patterns and indices of genetic diversity in the koala (Phascolarctos cinereus), a highly specialised folivorous marsupial that is experiencing rapid and widespread population declines across much of its former range. Our findings demonstrate that current management divisions across the state of New South Wales (NSW) do not fully represent the distribution of genetic diversity among extant koala populations, and that care must be taken to ensure that translocation paradigms based on these frameworks do not inadvertently restrict gene flow between populations and regions that were historically interconnected. We also recommend that koala populations should be prioritised for conservation action based on the scale and severity of the threatening processes that they are currently faced with, rather than placing too much emphasis on their perceived value (e.g., as reservoirs of potentially adaptive alleles), as our data indicate that existing genetic variation in koalas is primarily partitioned among individual animals. As such, the extirpation of koalas from any part of their range represents a potentially critical reduction of genetic diversity for this iconic Australian species.
... The success of this process may vary considerably. In Australia, over half of the translocations undertaken fail in producing self-sustaining populations (Fischer and Lindenmayer 2000;Short 2009; Moseby et al. 2015). ...
Article
Animal social relationships affect animal survival, reproduction, and resource exploitation, and are important to translocation success, but little is known on how they are impacted in reintroduced populations. Here, we investigate the social genetic structure in a reintroduced population of boodies (Bettongia lesueur), one of few social burrowing marsupial species in Australia. Pairwise relatedness of male and female individuals located within seven warrens was determined using 12 microsatellite markers, while mitochondrial DNA was used to identify maternal ancestral lineage. Females were significantly more related within warrens than between warrens, while the difference among males was not significant. We also found evidence of fine-scale genetic structure up to distances of 2 km in females consistent with patterns found in natural populations. Although mean relatedness values were low, our results support the hypothesis that boodies exhibit a female social structure. Multiple maternal lineages were present within all warrens with one exception, suggesting boodies appear to be non-selective when living with individuals from different ancestral backgrounds. We found a significant positive relationship between female sex bias and the number of active entrances in each warren. Together, these results suggest that social structuring should be a key consideration in future reintroductions of boodies.
... Humans are more likely to show preferences for the survival of phylogenetically closer species (Tisdell et al., 2006), potentially due to feelings of compassion and empathy that are common for such species (Miralles et al., 2019;Prokop et al., 2021). As a result, species that are phylogenetically closer to humans are over-represented within conservation education campaigns (Clucas et al., 2008), conservation projects (Fischer & Lindenmayer, 2000), and the scientific literature (Albert et al., 2018). Nevertheless, despite the potential to influence decisions to sponsor particular animal species, the effect of phylogenetic distance from humans on zoo animal sponsorship is poorly known. ...
Article
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Public donations are an important form of fundraising for zoos and are used to support conservation activities. Understanding what influences zoo animal sponsorship by the public is crucial if zoos are to optimize strategies for increasing income from sponsors. Using sponsorship data obtained from seven diverse zoos within the UK, we used a phylogenetically informed approach to investigate predictors of the number of sponsors a species receives. We found no support for an effect of body mass, conservation status, solitary versus group housing, phylogenetic distance from humans, daily activity patterns, or the diet of the species on the number of sponsors a species attracts. However, we found strong phylogenetic signal, suggesting that particular groups of animals attract disproportionate sponsorship attention (but the specific species within these groups is of limited importance). Moreover, we found support for species with common names that are found toward the start of the alphabet having more sponsors. This is likely driven by the common practice of listing species that can be sponsored in alphabetical order when presenting them to potential sponsors (with people being more likely to choose species near the start of a list). Interestingly, the lack of effect of body mass, phylogenetic distance, and conservation status contrast with previous work on non‐zoo conservation preferences, suggesting possible differences between motivations of zoo and non‐zoo conservation donors, or between animal sponsorship and other forms of conservation involvement. We suggest two strategies for maximizing sponsorship for zoo animals. If zoos manage sponsorship income as a collective pool then allowing sponsorship of a range of species within particularly well‐sponsored animal groups should improve uptake. Alternatively, if zoos allocate sponsorship income to the specific species sponsored, then funding may be effectively diverted to priority species simply by altering the order of lists of animals which can be sponsored.
... Quenda is a species that is commonly translocated (Morris et al. 2015;Lohr and Valentine 2017), in part due to the number of individuals available from land clearing for housing and other developments in and around Perth ('salvage translocations') or from sites where quenda is deemed a pest species. However, little information is available on the longterm fate of reintroductions, despite reviews suggesting the importance of long-term monitoring (Fischer and Lindenmayer 2000;Short 2009;Sheean et al. 2012;Bubac et al. 2019). ...
Article
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Context Quenda (bandicoots, Isoodon fusciventer) have shown a major decline in range since European settlement, contracting to the more mesic coastal and forest zones in south-west Western Australia. Key actions to recover this species include broad-scale fox control, cat control and reintroductions. Most reintroductions have been to coastal and forest habitats. Aims To monitor the reintroduction of quenda to fox-free habitat of Wadderin Sanctuary in the wheatbelt of Western Australia, close to the eastern and drier margin of the species’ former range. Methods Relative abundance of the population was monitored over a 12-year period by regular standardised trapping throughout the sanctuary. Key results Quenda were reintroduced in 2010 and have persisted for >12 years. They were protected from fox predation by an exclusion fence, but were subject to a low level of cat predation for the first 8 years. Quenda showed both a ~20% drop in mean body condition over time and a trend of decreasing number of pouch young per female over time, likely a result of a succession of dry years and intra-and inter-specific competition for food resources. However, despite this, the index of abundance suggests that quenda numbers substantially increased, aided by high annual recruitment, in years following removal of the feral cat. Conclusions Quenda appear resilient at this site despite consecutive years of very low rainfall and apparent competition for food resources. Implications Quenda seem able to persist on the drier margin of their former range when protected from high levels of predation.
... However, setting aside any potential bias associated with the activities of the Department of Environment in Iran, it is presently reported that more than 400 deer are inhabiting a total of 12 enclosures established across the country [43][44][45]. While translocation to enclosed areas appears to have been successful in terms of increasing the species' population under human care, it's important to note that translocation success is ultimately defined as the establishment of self-sustaining new populations in the target areas [66] for a significant duration, contingent upon the lifespan of the species [67]. To assess the effectiveness of translocation programs, various criteria have been reported, including the establishment of a Minimum Viable Population (MVP), successful breeding of the first wild-born animals, achieving a positive recruitment rate over three years, quantifying post-release survival and reproduction rates, and determining the finite rate of increase [34,67,68]. ...
Article
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The Persian fallow deer or Mesopotamian fallow Deer ( Dama mesopotamica , Brook 1875), a species of significant ecological importance, had faced the threat of extinction in Iran. One conservation strategy involved the translocation of Persian deer to enclosed areas across Iran, where they were afforded protection from external threats and provided with essential care by human caretakers. While human caretakers diligently attend to their needs and mitigate external threats, climate variables may now become critical factors affecting population dynamics in enclosed areas. This study aims to assess the similarity in climate niches between the original area (Dez and Karkheh) of the Persian deer species and 11 newly enclosed areas. To achieve this, we employed climate data and ecological niche modeling (ENM) techniques to assess the variations in climate among 12 areas. We utilized the environmental equivalency test to determine whether the environmental spaces of area pairs exhibit significant differences and whether these spaces are interchangeable. Extrapolation analyses were also constructed in the next steps to explore climatic conditions in original fallow deer habitats that are non-analogous to those in other parts of Iran. Our results reveal significant disparities in climate conditions between the original and all translocated areas. Based on observations of population growth in specific enclosed areas where translocated deer populations have thrived, we hypothesize that the species may demonstrate a non-equilibrium distribution in Iran. Consequently, these new areas could potentially be regarded as part of the species’ potential climate niche. Extrapolation analysis showed that for a significant portion of Iran, extrapolation predictions are highly uncertain and potentially unreliable for the translocation of Persian fallow deer. However, the primary objective of translocation efforts remains the establishment of self-sustaining populations of Persian deer capable of thriving in natural areas beyond enclosed areas, thus ensuring their long-term survival and contributing to preservation efforts. Evaluating the success of newly translocated species requires additional time, with varying levels of success observed. In cases where the growth rate of the species in certain enclosed areas falls below expectations, it is prudent to consider climate variables that may contribute to population declines. Furthermore, for future translocations, we recommend selecting areas with climate similarities to regions where the species has demonstrated growth rates.
... In contrast, in Mediterranean areas of Spain and Portugal, the species selects dry crops with a high diversity of habitat characteristics, scrublands of yellow broom (Retama sphaerocarpa) and alfa grass (Stipa tenacissima), and riparian vegetation, often in non-permanent water courses (Mestre et al. 2007, Barrientos and Bolonio 2009, Barrientos and Miranda 2012, where rabbits, its main prey here (Santos et al. 2009), are particularly abundant. Before accomplishing any translocation or stocking (which can also encompass artificial selection; Horreo et al. 2008), the causes leading to population decline must be clearly identified and reversed or population reinforcement will fail (Fischer and Lindenmayer 2000). In this sense, several potential factors affecting polecat populations have been suggested, from habitat alteration, prey scarcity, poisoning or human-related mortality to hybridization and competition with other mustelids (Barrientos 2015, Sainsbury et al. 2018 ...
Article
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Volunteer‐based roadkill monitoring schemes, including road carcass sampling, can represent considerable advances with respect to classical methods employed in conservation biology. We studied the genetic diversity, structure, and dynamics of the European polecat ( Mustela putorius ) across the Iberian Peninsula. We used samples of road carcasses collected by volunteers because this carnivore is an elusive species otherwise difficult to monitor with standard field protocols. We gathered 238 samples obtained from 2004 to 2022 from 13 different areas (8–31 samples/area). Using microsatellite loci, we identified 4 genetic units with gene flow among 3 of them in the Iberian Peninsula. The genetic variability was steadily low in 1 of the areas (Girona) for all the parameters evaluated. This area is also genetically isolated from the other studied areas. The inbreeding coefficient was significant in the north‐ and south‐Iberia units, and we did not detect a bottleneck signature in any of the 4 genetic units. Future conservation actions should consider the genetic dissimilarity among detected units and elucidate the ecological factors that have led to the observed genetic patterns.
... Reintroduction is an important tool used worldwide to protect species that are endangered or even extinct in some countries or regions (Fischer and Lindenmayer 2000;Seddon et al. 2007;Bajomi et al. 2010). One of the most famous and perhaps the most effective example of bringing back species to their former native range is the series of conservation programmes aimed at protecting the ecosystem engineer Eurasian beaver (Castor fiber) and strengthening its population across Europe (Halley et al. 2012). ...
Article
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The Eurasian beaver is an ecosystem engineer species capable of altering the riparian vegetation and the hydrology of freshwater habitats. The study of its distribution process is therefore important for both nature conservation and conflict management. Thanks to protection efforts and natural expansion, the beaver has already inhabited most of its former range, starting from the brink of extinction. The changes in the Eurasian distribution and population size have been continuously documented in the scientific literature. In these studies, however, Hungary, as a country with an important position along the beavers’ colonisation routes provided by the Danube drainage basin, has hitherto been underrepresented due to a severe lack of data. In this paper, we summarise all the available information about the thirty-year history, colonisation process, current distribution, as well as the management of the Hungarian population. Based on the newest available data, the beaver is present along all of the large rivers and along most permanent watercourses in the country. Despite the continuing growth trend of the population, a beaver management strategy has not yet been developed. Its establishment could be significantly supported by further monitoring surveys and scientific studies focusing on the region- and site-specific ecological effects of the species.
... The primary goal of a translocation is to restore a species to an area from which it has been extirpated (reintroduction), enhance existing populations (reinforcement), replace extinct species (ecological replacement), or establish populations beyond the species' native range (assisted colonization) (Seddon 2010). Despite their popularity, translocations have achieved only low levels of "success", which has been attributed to poor planning and monitoring (Griffith et al. 1989;Seddon 1999;Fischer and Lindenmayer 2000). A second contributing factor may be unreasonably high expectations over short time frames (for instance, establishing a self-sustaining population from a single translocation). ...
Article
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Translocations are a critical tool for reversing biodiversity loss but are often characterized by unreasonably high expectations, leading to many translocation programs being brief and terminated before achieving their full potential. To address these issues, we developed the “Translocation Continuum Framework”, an easy‐to‐use tool that clarifies the criteria, strategies, tactics, progress measures, and expected outcomes for five key translocation “phases”: Feasibility Studies, Pilot Studies, Primary Trials, Secondary Experiments, and Tertiary Reinforcements. By accounting for uncertainty, the Framework aims to empower practitioners to design translocation programs that suit their context. We also discuss the limitations of “success” and “failure” labels in translocations, and the importance of parsimonious decision making to maximize learning with the least amount of loss. Only by managing expectations of the likelihood of establishment, growth, and regulation throughout a program's lifetime can we galvanize trust and investment in translocations so they can contribute meaningfully to long‐term restoration.
... Reports on the long-term status of translocated populations of herpetofauna are also rare (Seigel and Dodd 2002): several researchers have observed that post-release monitoring is only occasionally performed, and when data is gathered it is rarely published (Dodd and Seigel 1991, Bullock et al. 1996, Clemons and Langton 1998, Fischer and Lindenmayer 2000, Sheean et al. 2012. As a result, much knowledge is being obtained but not disseminated, despite this being required by the JNCC for translocation projects (McLean 2003). ...
Research
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Translocation of species is a controversial conservation technique which is widely used but often has unknown outcomes. In the mid-2000s, populations of slow worm Anguis fragilis and grass snake Natrix natrix were translocated to a nature reserve in southwest London. A refugia-based survey of these reptiles has been running since their introduction, and this paper evaluates the success or otherwise of the releases. A total of 72 refugia were distributed across the reserve and the reptiles found under these were counted. The highest count for each year was used as a metric for comparison. Additionally, half of these refugia were made of felt and the other half made of tin, allowing a comparison of refugia material preference, by species and by age group. Analysis of refugia material preferences showed slow worms had a significant preference for felt refugia, while grass snakes showed a significant preference for tin refugia. These findings allow a future survey to target individual species more effectively. Good quality habitat has benefitted the slow worm population. They appear to be breeding in increasing numbers, and are spreading across the reserve. The grass snake population appeared to start well and began breeding rapidly, but after an initial peak, numbers of juveniles dropped substantially; adult numbers remain low. There are two likely causes of the grass snake decline: poor quality compost heaps, a vital breeding location for the species; and declining populations of breeding amphibians, their primary food source. This informs future translocation plans of the importance of these factors in grass snake translocation success. The long-term monitoring of these species has revealed the plight of the grass snake at the study site, allowing action to be taken before it is too late. This demonstrates the importance of long-term monitoring for the survival of translocated species.
... human effort). To ensure this cost is not in vain, it is important to set success criteria and to regularly monitor havened populations over time (Fischer and Lindenmayer 2000). Parameters that are essential to effective monitoring regimes include survival, especially of translocated founding individuals, and population growth, as these can be informative descriptors of early population establishment. ...
Article
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Context Predator free havens are increasingly relied upon to preserve populations of imperilled species, yet despite their substantial cost, the success of these ventures is rarely critically evaluated. Aims Based on 12 years of population monitoring data, we report on the translocation of woylies (Bettongia penicillata ogilbyi) to Perup Sanctuary, a 423 ha predator-free haven in the south west of Western Australia. Methods We built spatially explicit capture–recapture models to estimate population density, population growth rates, and survivorship of woylies inside the sanctuary. Using these estimates, and additional demographic information, we aimed to show key drivers of population density, evaluate the establishment of the sanctuary population against predetermined translocation success criteria, and run simulations of different sampling designs to determine a robust sampling design for future monitoring of this population. Key results The population rapidly increased in the first 3 years (2010–2013), and then fluctuated around a density of ~0.9 woylies ha⁻¹ before declining slightly in recent years to ~0.6 woylies ha⁻¹. All translocation success criteria evaluated were met. The previous 3 months’ rainfall was a key driver of population density and body weight declined over time, indicating that the population may be regulated by food resources. Conclusions Woylies have established and persisted in Perup Sanctuary, and against the criteria, the translocation of woylies into Perup sanctuary is a success. Harvests from this population appear to have been sustainable. We discuss these findings in the context of the Perup Sanctuary, and recommend ongoing monitoring continue to ensure that the population remains viable and well managed. Implications We describe important considerations for the supplementation and harvest of fenced populations, including: the source of animals (selecting free-living individuals over captive ones); the timing of release (releasing more individuals early on may improve establishment probabilities); and rates of harvest (<30% of adults harvested per generation seemeded to be sustainable for woylies in this case). The results from this study can inform the ongoing management of this and other havened populations, to ensure they continue to benefit mammal conservation.
... Additionally, achieving success (self-sustaining populations) with translocations can be challenging, with potential difficulties stemming from factors both intrinsic and extrinsic to the animal, such as the quality of the release habitat (including abiotic conditions and the presence of competitors and predators); environmental conditions like harsh weather; a lack of genetic or phenotypic diversity, possibly combined with local adaptation; and handling effects during collection and release (Seddon et al. 2014;Jourdan et al. 2019;Berger-Tal et al. 2020). Consequently, post-translocation monitoring, research, and publication of results, including unsuccessful attempts, is crucial to assess unbiased success rates and improve translocation methods (Fischer & Lindenmayer 2000;Jourdan et al. 2019). Current priority research needs for freshwater conservation include rigorous evaluations like before-after/ control-impact (BACI) designs (Maasri et al. 2022), particularly in translocations. ...
Article
Conservation translocations may be a useful tool for the restoration of declining freshwater invertebrates, but they are poorly represented in the literature. We conducted a before‐after/control‐impact (BACI) experiment to test the efficacy of conservation translocation for re‐establishing abundant populations of the amphipod Gammarus lacustris , a declining species and wildlife food resource in depressional wetlands in the upper Midwest of the United States of America. Each study site ( n = 19) contained at least one treatment wetland receiving translocated G. lacustris from a local donor and one control wetland. We selected study wetlands based on a suite of wetland characteristics and randomly assigned recipient versus control treatment. Gammarus lacustris was detected post‐translocation at only 2 of 22 recipient wetlands (1 of 19 sites). Overall, there was a statistical increase in G. lacustris density in recipient wetlands compared to controls; however, the results were of minimal biological significance due to being driven by a single site with low G. lacustris densities. Accordingly, our results suggest that future conservation translocations of amphipods might be successful if limited to recently restored wetlands or informed by a more complex habitat suitability model to differentiate dispersal limitations from habitat limitations. To develop such a model would involve identifying the fewest, most influential physical and biological factors (e.g. wetland size/structure, fish, aquatic vegetation, and water chemistry) from the numerous inter‐related factors that correlate with the abundance of naturally occurring G. lacustris ; candidate wetlands to receive amphipods would be those for which the model predicts abundant G. lacustris but in which they do not presently occur.
... Esto debe ser apoyado con indicadores de éxito definidos previamente dentro de una planificación que permita determinar el número de animales que podrían establecer una población autosustentada a largo plazo y el espacio necesario para su sustentación. En términos generales, en reintroducciones de ungulados se han observado mayores tasas de éxito cuando los individuos son de origen silvestre, en comparación con individuos provenientes de cautiverio[67]. Pero en caso de que se esté considerando la opción de extraer individuos fundadores de una población silvestre, debe evaluarse la potencial afectación de la viabilidad de la población de origen. Al respecto, los criterios de la UICN indican que, en ausencia de mejor información científica, los individuos deberían provenir de poblaciones cercanas geográficamente y de condiciones ecológicas similares. ...
Technical Report
El presente documento es resultado del trabajo colaborativo y voluntario de un conjunto de organizaciones y personas, quienes – en octubre de 2020 - conformaron un grupo de trabajo con el objetivo de realizar una planificación estratégica para la conservación del guanaco en Chile central, donde la especie se encuentra clasificada como Vulnerable
... muletensis (Kraaijeveld-Smit et al., 2006), potentially reducing a population's ability to be reintroduced to the wild successfully. This may be a contributing factor to the reduced success rate of reintroduction programmes for captive-born animals (13%) compared to wild translocations (31%) across 116 reintroduction programmes (Fischer & Lindenmayer, 2000). To mitigate against genetic adaptations to captivity, the number of generations in captivity should be reduced (Kleiman et al., 1994). ...
Article
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Fruit bats (genus Pteropus ) are typically island‐endemic species important in seed dispersal and reforestation that are vulnerable to increased extinction risk. An effective method of reducing extinction risk in vulnerable species that cannot be conserved in their native habitat is establishing an ex‐situ captive breeding programme. Due to anthropogenic threats and low population numbers, in the early 1990s, a captive breeding programme was established at Jersey Zoo, British Isles, for Critically Endangered Livingstone's fruit bats ( Pteropus livingstonii ). Here we use six polymorphic microsatellite loci to assess genetic diversity in the captive breeding population of Livingstone's fruit bats ( P. livingstonii ), 30 years after the programme's establishment, investigating change over generations and comparing our findings with published data from the wild population. We found no significant difference between the genetic diversity in the captive and wild populations of Livingstone's fruit bats ( P. livingstonii ), in both expected heterozygosity and allelic richness. The captive population has retained a comparable level of genetic diversity to that documented in the wild, and there has been no significant decline in genetic diversity over the last 30 years. We advise that a full pedigree of the paternal lineage is created to improve the management of the captive breeding programme and further reduce the possibility of inbreeding. However, it appears that the captive breeding programme is currently effective at maintaining genetic diversity at levels comparable to those seen in the wild population, which suggests reintroductions could be viable if genetic diversity remains stable in captivity.
... One such approach in species conservation in regions with high densities of farm ponds might be the translocation or repatriation of threatened species to these environments coupled with control of sportfish communities, thereby establishing self-sustaining populations that buffer losses due to anthropogenic alterations (Copp et al. 2007; Thomson and Berry 2009;Schumann et al. 2020;Pfaff et al. 2023). Translocation of wild individuals from stable populations can be a useful tool to increase the redundancy of populations and prevent local extirpation while maintaining genetic diversity (Minckley 1995;Fischer and Lindenmayer 2000;Seddon et al. 2007). ...
Article
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Small artificial impoundments such as farm ponds have recently been recognized as potential habitat for threatened native fish species. However, factors influencing translocation or colonization success into these environments, including connectivity to stream networks and interactions with existing fish community, are largely unknown. In this study we conducted a controlled experiment to quantify the influence of piscivorous Largemouth Bass Micropterus salmoides on the survival of a translocated native minnow species that we used as a surrogate for federally endangered Topeka Shiner Notropis topeka. We translocated or released 100 Bluntnose Minnow Pimephales notatus into each replicate treatment ponds with and without Largemouth Bass in the summers of 2020 and 2021. Each minnow was implanted with a passive integrated transponder (PIT) tag. Translocated populations were monitored using stationary and mobile passive integrated transponder antennas and estimates of apparent survival and probability of detection for each pond were derived from open population mark-recapture models. Apparent survival was nearly two times higher in ponds without bass suggesting predation by bass leads to higher mortality. Additionally, probability of detection was nearly 10 times higher in ponds without bass, suggesting reduced movement of translocated minnows when bass were present. While the direct effect of mortality impacts translocated populations, the indirect effect of altered behavior may also be impactful on translocation success. These results confirm that Largemouth Bass can limit the success of translocated minnow species.
... Comparing demographic responses such as survival, fidelity rates, and dispersal of translocated and non-translocated organisms can assist in evaluating the success of translocations (Healy, Budy, et al., 2022;Sheller et al., 2006;Yackulic et al., 2021). While translocations are commonly implemented, few efforts have been rigorously evaluated (Dresser et al., 2017;Fischer & Lindenmayer, 2000;Yackulic et al., 2021). ...
Article
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Fragmentation isolates individuals and restricts access to valuable habitat with severe consequences for populations, such as reduced gene flow, disruption of recolonization dynamics, reduced resiliency to disturbance, and changes in aquatic community structure. Translocations to mitigate the effects of fragmentation and habitat loss are common, but few are rigorously evaluated, particularly for fishes. Over six years, we translocated 1215 individuals of four species of imperiled fish isolated below a barrier on the San Juan River, Utah, USA, that restricts access to upstream habitat. We used re‐encounter data (both passive integrated transponder tag and telemetry detections and physical recaptures) collected between 2016 and 2023, to inform a spatially explicit multistate mark–recapture model that estimated survival and transition probabilities of translocated and non‐translocated individuals, both below and above the barrier. Individuals of all four species moved large (>200 km) distances upstream following translocation, with the maximum upstream encounter distance varying by species. Results from the multistate mark–recapture model suggested translocated fish survived at a higher rate compared with non‐translocated fish below the barrier for three of the four species. Above the barrier, translocated individuals survived at similar rates as non‐translocated fish for bluehead sucker (Catostomus discobolus) and flannelmouth sucker (Catostomus latipinnis), while survival rates of translocated endangered Colorado pikeminnow (Ptychocheilus lucius; mean, 95% CI: 0.75, 0.55–0.88) and endangered razorback sucker (Xyrauchen texanus; 0.86, 0.75–0.92) were higher relative to non‐translocated individuals (Colorado pikeminnow: 0.52, 0.51–0.54; razorback sucker: 0.75, 0.74–0.75). Transition probabilities from above the barrier to below the barrier were generally low for three of the four species (all upper 95% CI ≤ 0.23), but they were substantially higher for razorback sucker. Our results suggest translocation to mitigate fragmentation and habitat loss can have demographic benefits for large‐river fish species by allowing movements necessary to complete their life history in heterogeneous riverscapes. Further, given the costs or delays in providing engineered fish passage structures or in achieving dam removal, we suggest translocations may provide an alternative conservation strategy in fragmented river systems.
... For instance, natural habitats are generally very different from captive environments, and it has been demonstrated that captive individuals, when released in the natural environment, might have species fitness compromised due to changes in physiological, morphological, and behavioral traits (Kohane and Parsons 1988;Ruzzante and Doyle 1993;Lynch and O'Hely 2001;Wassink et al. 2022). Captive-reared individuals often have less capacity for quickly adapting to the natural habitat of their ancestors (Kleiman 1989;Fischer and Lindenmayer 2000;Seddon et al. 2007;Teixeira et al. 2007;Crates et al. 2022). ...
Article
Captive breeding and stocking are commonly employed strategies for enhancing fisheries and conserving endangered fish species. However, hatchery-raised fish often exhibit reduced performance in the wild, displaying alterations in physiological, morphological, and behavioral traits. We tested for differences in swimming capacity and metabolic traits between wild and hatchery-reared individuals of the Spanish toothcarp (Aphanius iberus) from two different populations. Furthermore, we experimentally tested if these changes translated into fitness differences after their stocking into the wild. There were significant differences in swimming capacity and metabolic traits between wild and hatchery-reared individuals and also between the two populations. Captive-bred individuals displayed consistently lower metabolic rates than wild individuals from the same population (30-76% lower). Critical swimming speed rather differed between the two populations. Sex-specific differences were observed in maximum and standard metabolic rates, with wild individuals and females generally exhibiting higher values but with some exceptions. During a three-month experiment, survival rates did not significantly differ between wild and captive-bred fish. Captive-bred individuals started smaller but exhibited rapid growth during the experiment. Initially, larger captive-bred fish had lower body condition than their wild counterparts, but these differences progressively diminished. In summary, captive-bred individuals of this fish species showed lower metabolic rates, although the differences with wild individuals slightly depended on sex and size.
... Reintroduction programs often seek to establish productive, selfsustaining natural populations (IUCN/SSC, 2013). However, they frequently fail to achieve their recovery and conservation objectives (Bellis et al., 2019;Bubac et al., 2019;Fischer & Lindenmayer, 2000;Godefroid et al., 2011). Many factors contribute to reintroduction success, or failure, including suitability of the source population (Bubac et al., 2019;Cochran-Biederman et al., 2015). ...
Article
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Reintroduction is an important tool for the recovery of imperiled species. For threatened Pacific salmonids (Oncorhynchus spp.) species, hatchery‐origin (HOR) individuals from a nearby source are often used to reestablish populations in vacant, historically occupied habitat. However, this approach is challenged by the relatively low reproductive success that HOR Pacific salmonids experience when they spawn in the wild, relative to their natural‐origin (NOR) counterparts. In this study, we used genetic parentage analysis to compare the reproductive success of three groups of adult Chinook salmon (Oncorhynchus tshawytscha) reintroduced above Cougar Dam on the South Fork McKenzie River, Oregon: HOR Chinook salmon from an integrated stock; first‐generation, wild‐born descendants (hereafter F1s) of Chinook salmon produced at the same hatchery; and NOR Chinook salmon that are presumed to have been produced below the dam, on the mainstem McKenzie River, or elsewhere and volitionally entered a trap below Cougar Dam. We found that F1s produced nearly as many adult offspring as NORs, and 1.8‐fold more adult offspring than HORs. This result suggests that, for the South Fork McKenzie reintroduction program, a single generation in the wild increases fitness for the descendants of HOR Chinook salmon. Although these results are encouraging, care must be taken before extrapolating our results to other systems.
Article
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Human-wildlife conflict has emerged as a global conservation issue. Large swaths of forest and biodiversity are under threat from human development operations that convert natural habitats into profitable agricultural landscapes and plantations. Elephants are also losing their habitats and corridors (traditional migratory routes) due to increased human populations, agricultural development, and infrastructure construction like roads, canals, and fences that split their habitats. Consequently, elephants come into contact with humans, which escalates human-elephant conflict (HEC). This often destroys crops and property and occasionally causes human and livestock fatalities. Elephants may be killed in retaliation as a result of these negative interactions. Hence, comprehending the dynamics of conflict patterns, their origins, and the reactions of involved parties becomes imperative in managing human-elephant conflict. Promoting the cultivation of crops that are less alluring to elephants while remaining economically feasible for local farmers has the potential to facilitate a shift in land use and income generation within areas where humans and elephants co-exist. Medicinal and aromatic plants (MAPs) rich in secondary plant compounds have shown promise as crops less affected by elephants. Cultivating suitable MAPs, particularly in and around elephant habitats, has the potential to provide a stable income for the farmers. Besides, MAPs are generally resistant to biotic and abiotic stress conditions and are well adapted to climate change. Therefore, such crops could be economically important options in reducing crop damage caused by elephants, mitigating human-elephant conflict and ensuring livelihood sustainability.
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Conservation biology draws from a diverse tange of academic fields. Already a number of textbooks are available on the subject. This book is the first attempt to place the concepts of conservation biology into a uniquely Australian context. The book aim1l to provide an introduction to the principles of conservation biology and supply information on the main quantitative methods and procedures important in detecting and solving conservation problems in Australia.
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Reviews information on relocations, repatriations, and translocations (RRT) projects involving amphibians and reptiles, examines the motives for advocating RRT strategies, and recommends biological and management criteria that should be considered prior to undertaking RRT projects. Most projects involving amphibians and reptiles have not demonstrated success as conservation techniques and should not be advocated as if they are acceptable management and mitigation practices. -from Authors
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Fifty percent of all the mammal species to have become extinct worldwide in the past 200 years have been lost from the Australian fauna giving Australia the worst record for mammal conservation of any country or continent. Sixteen species from a mammal fauna of 245 are believed to be extinct, 26 species now occur only as remnant populations occupying <20% of their former ranges. Offshore islands, tropical Australia, and the mesic fringe of the continent have provided refuges where mammal communities have survived.relatively intact. The drier interior regions, which include cereal growing areas, intensive and extensive pastoral areas, and the little-used Triodia deserts, have lost many species. Extinctions and declines have not occurred equally throughout the Australian fauna, but have occurred at a disproportionately higher rate among medium-sized ground-dwelling mammals in the weight range 0.035-5.500 kg. Historically, conservation of mammals has concentrated on protection from hunting and trade, reservation of land as national parks and nature reserves, and faunal surveys to map distribution and abundance. These approaches have been necessary but insufficient to either stabilize the decline of endangered mammals or to promote their recovery. The past 20 years have seen many attempts to conserve endangered mammals, either by evading the presumed cause(s) of extinction or decline by translocation to islands, or by managing these causes within reserves by controlling exotic predators, controlling or excluding exotic herbivores, or applying a particular fire pattern or regime. The most significant successes have come with effective control of exotic predators, either by establishing populations of endangered species on predator-free islands or by the intensive use of 1080 poison to control exotic predators at mainland sites.
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Disease may play an important role in the decline or extinction of small, isolated animal populations. Disease also has thwarted attempts to reintroduce some endangered captive-bred species. Despite this, the impacts of disease rarely have been considered in the planning and design of reintroduction programmes. A remnant wild population could be decimated by a disease cointroduced with reintroduced animals. Alternatively, diseases that are endemic in wild animal populations could be fatal for those immunologically naive individuals that are reintroduced. We contend that the planning of reintroduction programmes should include an examination of the potential impacts of disease on extant populations and on animals targeted for release. A number of steps are outlined to reduce disease risk and to minimise the probability of failure of reintroductions because of disease.
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Since 1986 the Conservation Commission of the Northern Territory has operated a programme to remove 'problem' saltwater crocodiles from waters in and adjoining the township of Nhulunbuy. Over a period of five years, 52 different saltwater crocodiles (44 male) were captured. Most (48) were released at remote sites designated by the traditional Aboriginal owners of the surrounding lands. Release distances from the township varied from 17 to 282 km (by coastline). Many crocodiles (47.9%), including those released at the most distant sites, returned to, and were subsequently recaptured at, the township. Total capture rates (initial captures and recaptures pooled) varied seasonally, with fewer crocodiles being caught in the cooler dry season. During the wet season capture rates remained high, but relatively fewer 'new' crocodiles were caught. Probability of recapture could not be related to distance and direction of release from the township, nor size and sex of the released crocodile. Frequency of capture of individual crocodiles (1-8 times) was also unrelated to these variables. The high rates of return indicate that relocation is unlikely to be an effective strategy for managing humancrocodile interactions, at least in areas where potential release sites already support saltwater crocodile populations near carrying capacity.
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Inbreeding depression is environmentally dependent, such that a population may suffer from inbreeding depression in one environment but not another. We examined the phenotypic responses of 35 inbred (F = 0.672) lineages of the red flour beetle Tribolium castaneum in two different climatic environments. We found a significant environmental effect on males but not females. More important, we found that the rank fitness order of lineages differs between environments; lineages of high fitness in one environment may have low fitness in another environment. This change in rank is evident in a significant genotype-by-environment interaction for inbreeding depression for both females and males. These results suggest that even if we know the average environmental effect of inbreeding depression in a population, for any particular lineage measurements of inbreeding depression in one environment may not predict the level of inbreeding depression in another environment. Conservation biologists need to be aware of the environmental dependency of inbreeding depression when planning wildlife refuges or captive propagation programs for small populations. Ideally, captive propagation programs should maintain separate lineages for release efforts. Refuge design programs should consider maintaining a range of habitat types.
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This study compared the growth and behavioral development of parent-reared, cross-fostered, and captive-reared Killdeer (Charadrius vociferus) chicks. Common species were used to test these techniques for possible application to rare endangered forms. Parent-reared chicks were raised naturally in the wild, cross-fostered chicks were raised by Spotted Sandpipers (Actitis macularia) in the wild, and captive-reared chicks were raised in captivity by humans. Both hatching and fledging success were significantly increased by captive-rearing, and cross-fostering produced approximately the same number of fledged young as natural parent-rearing. Captive-reared Killdeer chicks spent more time resting and less time feeding and stayed closer to siblings than cross-fostered or parent-reared chicks; these behavioral differences were not seen after release to the wild. Growth rates among the three groups were similar. All of the young Killdeer responded to Killdeer alarm calls. There was no evidence that captive-reared and cross-fostered Killdeer were negatively affected by their early experiences. Captive-rearing is a viable management technique for augmenting small populations of endangered shorebirds, such as the Piping Plover (Charadrius melodus). It is recommended over cross-fostering because captive-rearing is more flexible as a technique, produces more young, does not affect another species, and does not produce potential imprinting problems.
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The use of captive breeding in species recovery has grown enormously in recent years, but without a concurrent growth in appreciation of its limitations. Problems with (1) establishing self-sufficient captive populations, (2) poor success in reintroductions, (3) high costs, (4) domestication, (5) preemption of other recovery techniques, (6) disease outbreaks, and (7) maintaining administrative continuity have all been significant. The technique has often been invoked prematurely and should not normally be employed before a careful field evaluation of costs and benefits of all conservation alternatives has been accomplished and a determination made that captive breeding is essential for species survival. Merely demonstrating that a species' population is declining or has fallen below what may be a minimum viable size does not constitute enough analysis to justify captive breeding as a recovery measure. Captive breeding should be viewed as a last resort in species recovery and not a prophylactic or long-term solution because of the inexorable genetic and phenotypic changes that occur in captive environments. Captive breeding can play a crucial role in recovery of some species for which effective alternatives are unavailable in the short term. However, it should not displace habitat and ecosystem protection nor should it be invoked in the absence of comprehensive efforts to maintain or restore populations in wild habitats. Zoological institutions with captive breeding programs should operate under carefully defined conditions of disease prevention and genetic/behavioral management. More important, these institutions should help preserve biodiversity through their capacities for public education, professional training, research, and support of in situ conservation efforts.
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Translocation of individual carnivores has been a standard management tool for decades in North America and southern Africa in response to livestock depredation and other conflict behaviours. As carnivore populations across Europe begin to increase it is expected that management problems will also increase. Before translocation becomes established as a management tool in Europe its success needs to be reviewed. In general, there has been very little follow-up of translocated animals. Almost no data exist on the subsequent levels of damage after translocation. Large carnivores have shown a consistent ability to return to the site of capture over distances of up to 400 km. Even those individuals that do not succeed in returning home roam over very large distances, best measured in units of hundreds of kilometres. Very few individuals remain at the release sites. Survival of translocated animals has occasionally been shown to be poor, often as a result of the large movements. In general, there needs to be a large area (hundreds or thousands of square kilometres) without conflict potential where the individuals can be released for the strategy to work. When such areas are not available, management efforts should concentrate on reducing conflict potential, or, where this is not practical, lethal control.
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Reintroduction of animals to the wild to establish free-ranging viable populations is a valuable conservation tool, but ecological skills alone are not enough to ensure a successful reintroduction; also needed to do the work are effectively designed and managed programs. This article suggests general guidelines for organizing and managing reintroduction programs, reviews some basic organizational issues, and considers ways to develop high-performance teams The need to integrate reintroduction programs into their larger interorganizational context is discussed. The reintroduction program's structure must be appropriate for its function and should be properly staffed, led, and buffered from its political environment It should process information well, learn rapidly from its own mistakes, and be creative A high-performance team devotes most of its energies to solving external rather than internal problems
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Translocations have been widely used to conserve threatened fauna worldwide, and although the benefits of monitoring newly translocated animals are widely recognised, post-release monitoring seldom occurs. This paper reports the dispersal patterns, social organisation and survival of a newly translocated population of 26 South Island saddlebacks (Philesturnus carunculatus carunculatus), on Motuara Island, New Zealand. South Island saddlebacks dispersed widely through forest on Motuara Island after release and 8–10 months after release, territory sizes ranged from 1.9–8.8 ha ( ha, s=2.42). Saddlebacks in both subadult and adult plumage attempted to breed in the first breeding season after release and an estimated 10 fledglings were produced. Maximum mortality of the translocated group was 50% 8–10 months after release. Translocations of 15–59 South Island saddlebacks have been successful in the past, suggesting the success of the transfer to Motuara Island is not jeopardised by the relatively small size of the founder group. Saddlebacks appear relatively flexible in habitat requirements and are capable of high reproductive output, enhancing the success of translocations of this species.
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This paper describes six recent attempts to conserve threatened wallabies (Marsupialia: Macropodoidea) by reintroduction. All ended in failure. We place these attempts within the context of nineteen other reintroductions of macropods known to us. Success of reintroduction of macropods appears to depend critically on control or exclusion of exotic terrestrial predators. Islands without exotic predators support a success rate of reintroductions an order of magnitude higher than that of mainland sites and islands with exotic predators (82% cf. 8%).Reintroductions have generally been poorly monitored and poorly documented. Researchers have often failed to appreciate the enormity of the task of controlling introduced predators (foxes and feral cats and dogs) and herbivores (rabbits), and to make adequate use of existing technology (radiotelemetry), and have been unable to overcome the logistical problems of managing reintroductions far from their research bases. Successes in management and reintroduction of other threatened fauna in Australia suggest that effective control of introduced predators and rabbits using the poison 1080, for which many native species have a high tolerance, may provide an effective means of managing mainland reintroductions.
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Due to over-hunting c. 1200 Eurasian beavers Castor fiber survived in eight relict populations in Europe and Asia at the beginning of the 20th century. Following hunting restrictions and translocation programmes in 15 countries, the Eurasian beaver became re-established over much of its former range, and presently numbers c. 430 000. The translocated populations often consist of a mixture of geographical forms. Preservation of the original, unmixed populations has therefore top priority: all five in Europe have reached the assumed minimum viable population size of c. 1880 animals each, but the three in Asia are still endangered. Their protection should be carried out at the level of river catchments. Nowadays the main threats for beavers are habitat destruction and introduced North American beavers Castor canadensis. On the other hand, growing beaver populations cause increasing conflicts with man, and population and/or damage control may therefore be required. In view of these two very different problems, we conclude that the conservation of beavers is best served by preservation and restoration of riparian woods with intact natural water regimes.
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Inbreeding is known to lead to decreased survival and reproduction in captive populations of animals. It is also important to know whether inbreeding has deleterious effects in natural habitats. An estimate was made of the effects of inbreeding in white-footed mice, Peromyscus leucopus noveboracensis, derived from a wild population. This study demonstrates that inbreeding had a significant detrimental effect on the survivorship of mice reintroduced into a natural habitat. This effect was more severe than the effect observed in laboratory studies of the population.
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As the human impact on the earth leads to ever increasing environmental degradation, the restoration of dwindling populations of numerous plant and animal species is becoming ever more important. In this unique volume, the political, biological and experimental procedures affecting the restoration of natural populations are examined using a range of case studies.
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In Australia, Trichosurus vulpecula has adapted to life in urban areas, often conflicting with human interest there. This study investigated the fate of 64 possums trapped in Melbourne, Victoria, and translocated to nearby forest. Translocated possums rapidly disappeared from the study area following release, probably due both to predation and dispersal. The high mortality and low rate of establishment of urban possums in the release area appeared to be related to their unfamiliarity with the site and naivety in relation to the forest environment. Released possums denned frequently on the ground. They were also observed a higher percentage of time on the ground in transit and appeared to be less wary than resident possums. Translocation does not appear to be a viable tool in the management of nuisance urban possums and other ways of resolving human-possum conflicts need to be sought. -from Author
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European beaver, Castor fiber (Linnaeus, 1758) was reintroduced into the lowland part of the Vistula basin in 1975-1985. The animals originated from the river basins of Neman and Pergola rivers or came from a beaver farm. Sixteen small populations were formed, composing 2 to 11 (mostly 4) families. The total number of the reintroduced beavers was 168, and in the first year they set up 64 sites.
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As part of a study of Odocoileus virginianus in the Chicago Metropolitan Area, the fates of deer captured on metropolitan preserves and translocated to a rural location were monitored. Survival of translocated deer is contingent upon capture and handling procedures, nutritional status of the animals, and the presence of decimating factors at the release site including hunters, vehicular traffic and predators. Additional considerations are habitat quality, density of resident deer at the release site, and resultant negative interactions (eg competition for resources, transmission of diseases or parasites) between translocated and resident deer. -from Authors
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Reviews 33 introductions of Rangifer tarandus that took place in E North America from 1924-1985: 20 introductions resulted in sustained populations, and 13 failed. Outside Newfoundland, 6 introductions failed when animals were released where deer were common. In these instances, caribou probably contacted meningeal worm. In Newfoundland, 5 introductions failed when the animals joined nearby herds. Predation (natural and hunting) and disease from deer were probably major factors in the decline of caribou in E North America with settlement. -from Authors
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From February 1975 to May 1978, 104 wolves (Canis lupus) captured at or near Minnesota farms where depredations on livestock had been reported were translocated northward and eastward for 50-317 km into extensive forests; 3 others were released westward. Nine wolves were translocated twice, and one three times. Information on movements was obtained by radiotracking 17 wolves and by recovery of 16 others. All radio-tagged wolves left the release areas; adults left quickly, but pups generally remained longer, behaved less decisively, and settled nearby temporarily. Wolves released together did not remain together. Initial travel of most radio-tagged adults was between south and west, the general direction to their original location. Final directions were primarily to the west and northwest, due in part to physiographic barriers. Eight adults homed, one twice, to capture areas that were less than 64 km from release sites. Nonhoming wolves were radiotracked and/or recovered 32-351 km from their capture sites and 23-302 km from their release sites. Translocation was largely unsuccessful at keeping problem wolves out of livestock production areas. The problem of initial travel away from release sites in wolf reintroductions probably could be minimized by transport and release of 6- to 9-month-old wolves.
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To develop techniques for future releases of captive-reared California condors (Gymnogyps californianus) to the wild, we used captive-reared Andean condors (Vultur gryphus) as surrogates. Hatched at facilities in the United States, 11 young Andean condors were transported to an isolated study site on the coast of northern Peru and released under experimental conditions. Six of these condors were raised by their parents then held with other juveniles in large aviaries before being shipped to Peru. They were between 1 and 3 years old when released. The other 5 condors were hand reared with the aid of puppets that closely resembled adult condors. They were released at the age when natural fledging occurred. Over periods of 170-260 days we taught these released birds how to forage by placing carcasses at progressively greater distances from the release site until the birds' foraging area was large enough that they encountered natural carcasses more frequently than those we offered. At this point they rapidly became independent of our care. The 6 birds released at an older age integrated with the wild population more rapidly than did the 5 birds released at fledging age; however, we had better control over the behavior and movements of the fledgingage birds. Seven of the 11 birds successfully reached independence and survived ≥18 months after their release.
Article
Forty-seven brown bears (Ursus arctos) were captured and transplanted in Alaska in 1979. Post-release data were adequate to evaluate the survival and homing movements for 20 adults and 9 young. At least 12 adults (60%) successfully returned from an average transplant distance of 198 km. Age (for males) and distance transplanted (sexes combined) were directly related to observed incidence of return (P
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In 1993 we conducted a follow-up study of the 1987 survey by Griffith et al. (1989) of 421 avian and mammalian translocation programs in North America, Australia, and New Zealand to reassess the programs’ status and the biological and methodological factors associated with success. Our survey response rate was 81%. Approximately 38% of usable programs in 1993 reported a change in outcome from 1987 (e.g., a translocated population was “declining” but now is “self-sustaining”), but the difference between the overall success rates was not statistically significant (66% in 1987 and 67% in 1993). Since 1987, an increase was observed in the median number of animals translocated per program (31.5 to 50.5), median duration of releases (2 to 3 years), and proportion of programs releasing more than 30 animals (46% to 68%). Multiple logistic regression analyses indicated that release into the core of the historical range, good-to-excellent habitat quality, native game species, greater numbers of released animals, and an omnivorous diet were positively associated with translocation success. Moreover, our results indicate that translocated birds were less successful at establishing self-sustaining populations than translocated mammals. Our findings, using comparable logistic analyses, generally corroborate the results of Grifftth et al. (1989). Variables not found to be significantly correlated with translocation success include species’ reproductive potential (number of offspring and first age of reproduction), number and duration of the releases, and source of the translocated animals (wild-caught versus captive-reared).