Revisiting translocation and reintroduction programmes: the importance of considering stress

Effects of captive-breeding conditions on metabolic and performance traits in an endangered, endemic cyprinidontiform fish

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 2 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 2 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 2 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 3-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 conditions 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.

Reasons for admission and rehabilitation rates of various wildlife species in Finland

Wildlife rehabilitation is a common part of animal-protection work. In Finland wildlife care is usually based on volunteer work and no licensing or training is required. Wildlife casualties are also treated professionally in some contexts such as zoos. The species of wildlife casualties may influence treatment decisions. Our anonymous online survey examined wildlife caregiving practices in Finland (n = 78), focusing on the care provided to various animal species and the outcomes of rehabilitation efforts. The survey was sent to both veterinarians and volunteers caring for wildlife, and it was part of a larger survey. Questions were mainly closed, and opinion-related questions were applied on a Likert scale (1-7; where 1 meant strongly disagree and 7 meant strongly agree). Most respondents primarily cared for mammals and birds. Reptiles, amphibians, and fish received less attention. Injuries and overwinter survival, especially in the case of hedgehogs, were the primary reasons for wildlife admissions. The training background of the rehabilitators varied and was related to the animal species being treated. Those caring mainly for hedgehogs (Erinaceus europaeus) were the least likely to have animal-related training or long-term experience in wildlife care. We show a notably high rehabilitation rate of approximately 80% of commonly treated species, significantly surpassing figures from other countries, which raises concerns that animals are admitted or released on too light grounds, leading to animal welfare problems. It is also noteworthy that only one-fifth of respondents said they kept records of animal admissions. Less than 40% of respondents emphasized the need for further education on any specific issue, which may indicate overestimation of personal skills. In conclusion, our study raises concerns regarding the ethics and potential harm associated with wildlife rehabilitation.

Agonistic interactions and social behaviors in the Saharan Dorcas gazelle (Gazella dorcas neglecta): Using social network analysis to evaluate relationships and social structure in captive male groups

Social interactions, including agonistic behavior, are very important for the management and welfare of individuals forming groups in captivity. One of the main concerns for the stability and durability of adult male groups is a noticeable level of intraspecific aggression. This study comprises a Social Network Analysis to illustrate social structure in different groups of captive Saharan Dorcas gazelles (Gazella dorcas neglecta). Our main objectives were to examine the relationship between agonistic, affiliative, and association networks and their reciprocity, assessing also whether the agonistic networks can conform to a linear dominance hierarchy. For these purposes, we recorded the behavior of 23 adult males organized in five herds, three composed only of Saharan Dorcas gazelle males and two mixed herds in which there were also Mhorr gazelle males (Nanger dama mohor). Observations were carried out during 295 h through scan sampling. We found no correlation between the affiliative and association networks in any group, although there was a significant correlation between the agonistic and association networks in mixed-species groups which was not present in single-species groups. Overall, there was no consistent reciprocity in either affiliative nor agonistic networks and none of the agonistic networks showed a linear structure. These results indicate that affiliative behavior in Saharan Dorcas gazelles offers distinctive and valuable information about the bonds between individuals, however, their dominance structure is far more complex than previously thought. As information provided by affiliative and proximity behaviors is different in this species, we suggest considering affiliative interactions to stablish affinity between individuals. Evaluating different social behaviors and not only agonistic interactions in later studies, is also recommended to develop a more accurately daily management in zoos that guarantee group stability and individuals' welfare, which will improve the conservation of captive populations.

Feather corticosterone is lower in translocated and historical populations of the endangered Laysan duck (Anas laysanensis)

Identifying reliable bioindicators of population status is a central goal of conservation physiology. Physiological stress measures are often used as metrics of individual health and can assist in managing endangered species if linked to fitness traits. We analysed feather corticosterone, a cumulative physiological stress metric, of individuals from historical, translocated, and source populations of an endangered endemic Hawaiian bird, the Laysan duck (Anas laysanensis). We hypothesized that feather corticosterone would reflect the improved reproduction and survival rates observed in populations translocated to Midway and Kure Atolls from Laysan Island. We also predicted less physiological stress in historical Laysan birds collected before ecological conditions deteriorated and the population bottleneck. All hypotheses were supported: we found lower feather corticosterone in the translocated populations and historical samples than in those from recent Laysan samples. This suggests that current Laysan birds are experiencing greater physiological stress than historical Laysan and recently translocated birds. Our initial analysis suggests that feather corticosterone may be an indicator of population status and could be used as a non-invasive physiological monitoring tool for this species with further validation. Furthermore, these preliminary results, combined with published demographic data, suggest that current Laysan conditions may not be optimal for this species.

Biological validation of faecal corticosterone metabolites as a non-invasive stress assessment in translocated California valley quail (Callipepla californica)

US quail species are vulnerable to population declines as a result of climate change, habitat loss and habitat fragmentation, all of which can result in physiological stress. Additionally, population restoration techniques (PRTs), like translocations, also induce stress. Traditional assessments of avian stress hormone levels include capturing and handling birds to extract blood, methods that are inherently stressful and can compound stress analyses. However, the stress hormone corticosterone (CORT) is metabolized from the blood and excreted in faeces as faecal corticosterone metabolites (FCMs). FCMs have been used as a non-invasive measurement of stress hormone levels in a variety of species, but must be validated for each species. The objective of this study was to biologically validate the use of FCMs as a non-invasive measurement of CORT levels in California valley quail (Callipepla californica). Reference and treatment quail were acclimated for 3 weeks in an outdoor aviary. Subsequently, treatment quail were subjected to a simulated 48-h translocation, a common and stress hormone-inducing PRT. Faecal samples were collected every 4 h and processed using an enzyme immunoassay. Mean FCM concentrations of treatment quail (41.50 ± 16.13 ng/g) were higher than reference FCM concentrations (24.07 ± 10.4 ng/g). These results biologically validate the use of FCMs as a non-invasive method to assess CORT levels in California valley quail, demonstrate diurnal variation in quail CORT levels, and confirm that quail translocations are a stress-inducing PRT. Ultimately, this research validates a new non-invasive tool for stress response measurement to advance quail research, management and conservation.

The fitness consequences of wildlife conservation translocations: a meta-analysis

Conservation translocation is a common strategy to offset mounting rates of population declines through the transfer of captive- or wild-origin organisms into areas where conspecific populations are imperilled or completely extirpated. Translocations that supplement existing populations are referred to as reinforcements and can be conducted using captive-origin animals [ex situ reinforcement (ESR)] or wild-origin animals without any captive ancestry [in situ reinforcement (ISR)]. These programs have been criticized for low success rates and husbandry practices that produce individuals with genetic and performance deficits, but the post-release performance of captive-origin or wild-origin translocated groups has not been systematically reviewed to quantify success relative to wild-resident control groups. To assess the disparity in post-release performance of translocated organisms relative to wild-resident conspecifics and examine the association of performance disparity with organismal and methodological factors across studies, we conducted a systematic review and meta-analysis of 821 performance comparisons from 171 studies representing nine animal classes (101 species). We found that translocated organisms have 64% decreased odds of out-performing their wild-resident counterparts, supporting claims of systemic issues hampering conservation translocations. To help identify translocation practices that could maximize program success in the future, we further quantified the impact of broad organismal and methodological factors on the disparity between translocated and wild-resident conspecific performance. Pre-release animal enrichment significantly reduced performance disparities, whereas our results suggest no overall effects of taxonomic group, sex, captive generation time, or the type of fitness surrogate measured. This work is the most comprehensive systematic review to date of animal conservation translocations in which wild conspecifics were used as comparators, thereby facilitating an evaluation of the overall impact of this conservation strategy and identifying specific actions to increase success. Our review highlights the need for conservation managers to include both sympatric and allopatric wild-reference groups to ensure the post-release performance of translocated animals can be evaluated. Further, our analyses identify pre-release animal enrichment as a particular strategy for improving the outcomes of animal conservation translocations, and demonstrate how meta-analysis can be used to identify implementation choices that maximize translocated animal contributions to recipient population growth and viability.

Social networks of reintroduced Przewalski's horses in the Great Gobi B Strictly Protected Area (Mongolia)

Analyzing social networks is a powerful tool for understanding the ecology of social species. While most studies focus on the role of each group member, few compare groups with different characteristics. The current population of Przewalski's horses Equus ferus przewalskii at the Great Gobi B Strictly Protected Area (Mongolia) includes groups of wild-born and captive-bred individuals with different experiences with the area (acclimatizing, long-term reintroduced, and wild-born), therefore serving as an ideal natural behavioral lab. We filmed 11 groups for 141.5 hours in summer 2018 (July), late spring 2019 (May, June), and autumn 2019 (September, October). Affiliative and agonistic interactions were recorded, and social networks were created. We tested the influence of origin, experience, season, sex, age, relative time belonging to the group, relatedness, and dominance rank on different network indices at the individual and group levels. We found that groups with greater experience in the area are generally better connected than members of the newly formed groups. However, these strong networks were created by wild-born individuals with very low interaction rates. On the contrary, inexperienced groups composed of captive-bred individuals displayed many interactions but created weak social networks. The results show a trend of behavioral transition from acclimatizing through long-term reintroduced to wild-born groups, supporting that the newly formed groups of released Przewalski's horses need time to display the typical social behavior patterns of wild-born individuals. Long-term monitoring of released Przewalski's horses is recommended to promote the success of this reintroduction program.

Review of hyperdispersal in wildlife translocations

Species translocation is a common tool to reverse biodiversity loss, but it has a high failure rate. One factor that contributes to failure is postrelease hyperdispersal, which we define as the long-distance movement of individuals resulting in their failure to contribute to population establishment. We reviewed reported incidences of hyperdispersal and compared rates of hyperdispersal among taxa, population demographics, release cohorts, and success of mitigation techniques. Of 151 conservation translocations (reinforcements and reintroductions) in which animals were tracked, hyperdispersal was confirmed in 52.1% of programs. The prevalence of hyperdispersal (percentage of studies) was relatively consistent across taxa (42.9-60%), but hyperdispersal rates in birds were likely underestimated because 76.9% of bird translocations showed incidences in which birds could not be located after release, but hyperdispersal was unable to be confirmed. Eutherians exhibited a higher average incidence of hyperdispersal (percentage of hyperdispersing individuals in a cohort) of 20.2% than birds, reptiles, and marsupials (10.4%, 15.7%, and 10.3%, respectively). No significant trends were observed for sex, source population, or translocation type, but there were nonsignificant trends for males to hyperdisperse more than females and for higher incidences of hyperdispersal in reinforcements relative to reintroduction programs. Mitigation techniques included temporary confinement, supplementation of resources, and releasing animals in social groups, but only half of studies examining mitigation techniques found them useful. Hyperdispersal incidence was variable within taxa, and we advise against forming translocations strategies based on results from other species. Hyperdispersal is a significant welfare, economic, and conservation issue in translocations, and we suggest definitions, reporting, and experimental strategies to address it.

Physiological plasticity in elephants: highly dynamic glucocorticoids in African and Asian elephants

Slowly reproducing and long-lived terrestrial mammals are often more at risk from challenges that influence fitness and survival. It is, therefore, important to understand how animals cope with such challenges and how coping mechanisms translate over generations and affect phenotypic plasticity. Rapidly escalating anthropogenic challenges may further diminish an animal's ability to reinstate homeostasis. Research to advance insights on elephant stress physiology has predominantly focused on relative or comparative analyses of a major stress response marker, glucocorticoids (GCs), across different ecological, anthropogenic, and reproductive contexts. This paper presents an extensive review of published findings on Asian and African elephants from 1980 to 2023 (May) and reveals that stress responses, as measured by alterations in GCs in different sample matrices, often are highly dynamic and vary within and across individuals exposed to similar stimuli, and not always in a predictable fashion. Such dynamicity in physiological reactivity may be mediated by individual differences in personality traits or coping styles, ecological conditions, and technical factors that often are not considered in study designs. We describe probable causations under the 'Physiological Dynamicity Model', which considers context-experience-individuality effects. Highly variable adrenal responses may affect physiological plasticity with potential fitness and survival consequences. This review also addresses the significance of cautious interpretations of GCs data in the context of normal adaptive stress versus distress. We emphasize the need for long-term assessments of GCs that incorporate multiple markers of 'stress' and 'well-being' to decipher the probable fitness consequences of highly dynamic physiological adrenal responses in elephants. Ultimately, we propose that assessing GC responses to current and future challenges is one of the most valuable and informative conservation tools we have for guiding conservation strategies.

Capture and transport of white rhinoceroses (Ceratotherium simum) cause shifts in their fecal microbiota composition towards dysbiosis

Translocations of Rhinocerotidae are commonly performed for conservation purposes but expose the animals to a variety of stressors (e.g. prolonged fasting, confinement, novel environment, etc.). Stress may change the composition of gut microbiota, which can impact animal health and welfare. White rhinoceroses in particular can develop anorexia, diarrhea and enterocolitis after translocation. The aim of this study was to investigate the associations of age, sex and translocation on the rhinoceros' fecal bacterial microbiota composition. fecal samples were collected from rhinoceroses at capture (n = 16) and after a >30-hour road transport (n = 7). DNA was isolated from these samples and submitted for 16S rRNA V3-V4 phylotyping. Alpha diversity indices of the rhinoceros' fecal microbiota composition of different age, sex and before and after transport were compared using non-parametric statistical tests and beta diversity indices using Permutational Multivariate Analysis Of Variance (PERMANOVA). Resulting P-values were alpha-corrected (Padj.). Alpha and beta diversity did not differ between rhinoceroses of different age and sex. However, there was a significant difference in beta diversity between fecal samples collected from adult animals at capture and after transport. The most abundant bacterial phyla in samples collected at capture were Firmicutes and Bacteroidetes (85.76%), represented by Lachnospiraceae, Ruminococcaceae and Prevotellaceae families. The phyla Proteobacteria (Padj. = 0.009) and Actinobacteria (Padj. = 0.012), amongst others, increased in relative abundance from capture to after transport encompassing potentially pathogenic bacterial families such as Enterobacteriaceae (Padj. = 0.018) and Pseudomonadaceae (Padj. = 0.022). Important commensals such as Spirochaetes (Padj. = 0.009), Fibrobacteres (Padj. = 0.018) and Lachnospiraceae (Padj. = 0.021) decreased in relative abundance. These results indicate that the stressors associated with capture and transport cause an imbalanced fecal microbiota composition in white rhinoceroses that may lead to potentially infectious intestinal disorders. This imbalance may result from recrudescence of normally innocuous pathogens, increased shedding of pathogens or increased vulnerability to new pathogens.

Ontogeny drives shifts in skin bacterial communities in facultatively paedomorphic salamanders

Microbiomes are major determinants of host growth, development and survival. In amphibians, host-associated bacteria in the skin can inhibit pathogen infection, but many processes can influence the structure and composition of the community. Here we quantified the shifts in skin-associated bacteria across developmental stages in the striped newt (Notophthalmus perstriatus), a threatened salamander species with a complex life history and vulnerable to infection by the amphibian chytrid fungus Batrachochytrium dendrobatidis and ranavirus. Our analyses show that pre-metamorphic larval and paedomorphic stages share similar bacterial compositions, and that the changes in the microbiome coincided with physiological restructuring during metamorphosis. Newts undergoing metamorphosis exhibited microbiome compositions that were intermediate between paedomorphic and post-metamorphic stages, further supporting the idea that metamorphosis is a major driver of host-associated microbes in amphibians. We did not find support for infection-related disruption of the microbiome, though infection replicates were small for each respective life stage.

Mitigating Human Impacts on Wild Animal Welfare

Human activities negatively impact the welfare of wild vertebrates in many different contexts globally, and countless individual animals are affected. Growing concern for wild animal welfare, especially in relation to conservation, is evident. While research on wild animal welfare lags behind that focused on captive animals, minimising human-induced harm to wild animals is a key principle. This study examines examples of negative anthropogenic impacts on wild animal welfare, how these may be mitigated and what further research is required, including examples from wildlife management, biodiversity conservation, wildlife tourism and wildlife trade. Further, it discusses the relationship between animal welfare and biodiversity conservation, and synergies that may be achieved between these. Ultimately, it is discussed how the welfare of wild animals may be balanced with other priorities to ensure that welfare is afforded due consideration in interactions between people and wildlife.

Ecological Considerations When Designing Mitigation Translocations: An Australian Reptile Case Study

Translocation science has made considerable progress over the last two decades; however, reptile translocations still frequently fail around the world. Major knowledge gaps surround the basic ecology of reptile species, including basic factors such as habitat preference, which have a critical influence on translocation success. The western spiny-tailed skink (Egernia stokesii badia) is used here as a case study to exemplify how empirical research can directly inform on-ground management and future translocation planning. A combination of studies, including LiDAR scanning of microhabitat structures, camera trapping, plasticine replica model experiments and unbounded point count surveys to assess predation risk, and visual and DNA analysis of dietary requirements, were all used to better understand the ecological requirements of E. s. badia. We found that the skinks have specific log pile requirements, both native and non-native predator management requirements, and a largely herbivorous, broad diet, which all influence translocation site selection and management planning. The use of E. s. badia as an Australian case study provides a clear strategic framework for the targeted research of meaningful ecological factors that influence translocation decision-making. Similar approaches applied to other reptile species are likely to fundamentally increase the capacity for effective management, and the likelihood of future successful translocations.

Arterial oxygenation and acid-base status before and during oxygen supplementation in captive European bison (Bison bonasus) immobilized with etorphine-acepromazine-xylazine

Chemical immobilization of captive European bison (Bison bonasus) is often required for veterinary care, transportation, or husbandry practices playing an important role in conservation breeding and reintroduction of the species. We evaluated the efficiency and physiological effects of an etorphine-acepromazine-xylazine combination with supplemental oxygen in 39 captive European bison. Animals were darted with a combination of 1.4 mg of etorphine, 4.5 mg of acepromazine, and 20 mg of xylazine per 100 kg based on estimated body mass. Arterial blood was sampled on average 20 min after recumbency and again 19 min later and analyzed immediately with a portable i-STAT analyzer. Simultaneously, heart rate, respiratory rate, and rectal temperature were recorded. Intranasal oxygen was started after the first sampling at a flow rate of 10 mL.kg^-1.min^-1 of estimated body mass until the end of the procedure. The initial mean partial pressure of oxygen (P_aO₂) was 49.7 mmHg with 32 out of 35 sampled bison presenting with hypoxemia. We observed decreased respiratory rates and pH and mild hypercapnia consistent with a mild respiratory acidosis. After oxygen supplementation hypoxemia was resolved in 21 out of 32 bison, but respiratory acidosis was accentuated. Bison immobilized with a lower initial drug dose required supplementary injections during the procedure. We observed that lower mean rectal temperatures during the immobilization event were significantly associated with longer recovery times. For three bison, minor regurgitation was documented. No mortality or morbidity related to the immobilizations were reported for at least 2 months following the procedure. Based on our findings, we recommend a dose of 0.015 mg.kg^-1 etorphine, 0.049 mg.kg^-1 acepromazine, and 0.22 mg.kg^-1 xylazine. This dose reduced the need for supplemental injections to obtain a sufficient level of immobilization for routine management and husbandry procedures in captive European bison. Nevertheless, this drug combination is associated with development of marked hypoxemia, mild respiratory acidosis, and a small risk of regurgitation. Oxygen supplementation is strongly recommended when using this protocol.

Assessing stress physiology within a conservation breeding program for an endangered species

Conservation breeding programs typically involve the management of individuals both in and ex situ, so it is vital to understand how the physiology of managed species changes in these environments to maximize program outcomes. The Vancouver Island marmot (VIM; Marmota vancouverensis) is one species that has been managed in a conservation breeding program to recover the critically low wild population. Previous research has shown there are differences in hair glucocorticoid concentrations for VIMs in different managed groups in the program. Therefore, we used >1000 blood samples collected since the program's inception to assess the neutrophil to lymphocyte (N:L) ratio among captive, pre-release, post-release and wild populations as another metric of stress. In situ VIM populations were found to have a significantly higher N:L ratio than ex situ populations, suggesting that the wild is a more physiologically challenging environment than managed care. Moreover, the effect of age, sex and the month of sampling on the N:L ratio were found to be different for each population. Age had the greatest magnitude of effect in the wild population, and sex was only significant in ex situ populations. This study provided previously unknown insights into the physiology of VIMs and increased post-release monitoring will be useful in the future to fully understand how physiology may be contributing to differences in survival of VIMs in the program.

Successful acclimatization of mandrills (Mandrillus sphinx) translocated to Conkouati-Douli National Park, Republic of Congo, as measured by fecal glucocorticoid metabolites

Translocation and reintroduction are common tools in conservation management and can be very successful. However, translocation can be stressful for the animals involved, and stress is implicated as a major cause of failure in release programs. Conservation managers should therefore seek to understand how the stages of translocation impact stress physiology in the animals involved. We quantified fecal glucocorticoid metabolites (fGCMs) as a noninvasive measure of response to potential stressors during a translocation of 15 mandrills (Mandrillus sphinx) into Conkouati-Douli National Park, Republic of Congo. The mandrills were initially housed in a sanctuary, transferred to a pre-release enclosure in the National Park and then released into the forest. We collected repeated fecal samples (n = 1101) from known individuals and quantified fGCMs using a previously validated enzyme immunoassay. Transfer from the sanctuary to the pre-release enclosure correlated with a significant 1.93-fold increase in fGCMs, suggesting that transfer was a stressor for the mandrills. fGCM values decreased over time in the pre-release enclosure, suggesting that the mandrills recovered from the transfer and acclimatized to the enclosure. Release to the forest was not linked to a significant increase in fGCMs over the final values in the enclosure. Following release, fGCMs continued to decrease, fell below sanctuary values after just over a month and were about half the sanctuary values after 1 year. Overall, our results suggest that the translocation, although initially presenting a physiological challenge to the animals, was not detrimental to the well-being of the animals over the timescale of the study and, in fact, may have been beneficial. Our findings show the value of non-invasive physiology in monitoring, evaluating and designing wildlife translocations and, ultimately, contributing to their success.

Interrupted Lives: Welfare Considerations in Wildlife Rehabilitation

Each year in the United States, thousands of sick, injured, or displaced wild animals are presented to individuals or organizations who have either a federal or state permit that allows them to care for these animals with the goal of releasing them back to the wild. The purpose of this review is to demonstrate the complexity of considerations rehabilitators and veterinarians face while trying to optimize the welfare of wild animals in need of care and rehabilitation. The process of rehabilitation is inherently stressful for wildlife. Maintaining an animal's welfare during the rehabilitation process-from initial contact and tria+ge to the animal's euthanasia, release, or captive placement-requires deliberate, timely and humane decision making. The welfare of wild animals can be improved by preventing human-related causes of admission, providing resources and support for wildlife rehabilitation (almost all rehabilitation in the United States is privately funded and access to veterinary care is often limited); further developing evidence-based wildlife rehabilitation methods and welfare measures, attracting more veterinary professionals to the field, harmonizing regulatory oversight with standards of care, training, and accountability, and increasing public education.

Population Dynamics of Community Cats Living in a Tourist Area of Onomichi City, Japan, before and after the Trap-Test-Vaccinate-Alter-Return-Monitor Event

The community cat program (CCP) was recommended by the Ministry of the Environment to reduce cats in local animal shelters and improve stray cat welfare in Japan. It is a non-lethal control measure with stray cats cared for as free-roaming cats for their lifetime in the community, while Trap-Neuter-Return (TNR) or Trap-Test-Vaccinate-Alter-Return-Monitor (TTVARM) activities are carried out. In the CCP, community cat colonies are hypothesized to be closed and static populations. However, it remains unknown whether the cats stay in the colonies, without migration of non-neutered cats following TNR/TTVARM events. We examined the population dynamics of cats before and after a TTVARM event using route censuses (107 days), fixed-point observations, and GPS-tracking in a tourist area in Onomichi. Eleven out of the 30 cats remained in the CCP areas, whereas 13 non-neutered cats immigrated into the CCP areas, within a year, suggesting the CCP program has limited efficacy. Besides, the program cannot support the lifetime management of the cats due rapid turnover of cats. Our results reject the CCP hypothesis, so that the program neither restricts cat breeding nor enhances cat welfare.

The phenotypic costs of captivity

The breeding of threatened species in captivity for release is a central tool in conservation biology. Given gloomy predictions for biodiversity trends in the Anthropocene, captive breeding will play an increasingly important role in preventing future extinctions. Relative to the wild, captive environments drastically alter selection pressures on animals. Phenotypic change in captive animals in response to these altered selection pressures can incur fitness costs post-release, jeopardising their potential contribution to population recovery. We explore the ways in which captive environments can hinder the expression of wild phenotypes. We also stress that the phenotypes of captive-bred animals differ from their wild counterparts in multiple ways that remain poorly understood. We propose five new research questions relating to the impact of captive phenotypes on reintroduction biology. With better use of monitoring and experimental reintroductions, a more robust evidence base should help inform adaptive management and minimise the phenotypic costs of captivity, improving the success of animal reintroductions.

Animal agency in wildlife conservation and management

Wildlife conservation and management (WCM) practices have been historically drawn from a wide variety of academic fields, yet practitioners have been slow to engage with emerging conversations about animals as complex beings, whose individuality and sociality influence their relationships with humans. We propose an explicit acknowledgement of wild, nonhuman animals as active participants in WCM. We examined 190 studies of WCM interventions and outcomes to highlight 3 common assumptions that underpin many present approaches to WCM: animal behaviors are rigid and homogeneous; wildlife exhibit idealized wild behavior and prefer pristine habitats; and human-wildlife relationships are of marginal or secondary importance relative to nonhuman interactions. We found that these management interventions insufficiently considered animal learning, decision-making, individuality, sociality, and relationships with humans and led to unanticipated detrimental outcomes. To address these shortcomings, we synthesized theoretical advances in animal behavioral sciences, animal geographies, and animal legal theory that may help conservation professionals reconceptualize animals and their relationships with humans. Based on advances in these fields, we constructed the concept of animal agency, which we define as the ability of animals to actively influence conservation and management outcomes through their adaptive, context-specific, and complex behaviors that are predicated on their sentience, individuality, lived experiences, cognition, sociality, and cultures in ways that shape and reshape shared human-wildlife cultures, spaces, and histories. Conservation practices, such as compassionate conservation, convivial conservation, and ecological justice, incorporate facets of animal agency. Animal agency can be incorporated in conservation problem-solving by assessing the ways in which agency contributes to species' survival and by encouraging more adaptive and collaborative decision-making among human and nonhuman stakeholders.

How Should We Help Wild Animals Cope with Climate Change? The Case of the Iberian Lynx

Climate change and related shifts in weather conditions result in massive biodiversity declines and severe animal suffering. This article explores the measures that can be taken to decrease animal suffering and prevent species from going extinct. Taking the Iberian lynx as a case study, we assess the extent to which it is beneficial for animal welfare and species conservation to do nothing or reduce other threats, provide food or shelter, relocate the species via assisted migration, or bring the population into captivity. We argue that, given the Iberian lynx's non-invasive characteristics, assisted migration may be the best way to protect the species while ensuring animal welfare and protecting wildness and other ecosystem values.

Resident wild koalas show resilience to large-scale translocation of bushfire-rescued koalas

Wildlife translocation is increasingly utilized as a conservation management action, to mitigate the immediate negative effects of habitat loss and fragmentation (e.g. from land clearing or bushfires). Previous research has shown that stress responses can help or hinder survival in translocated wildlife and determine the efficacy of translocation as a conservation action. Yet these translocated animals are only one side of the equation, with translocation also potentially impacting the animals in the recipient population. We measured physiological markers of stress (faecal cortisol metabolite concentrations and neutrophil-lymphocyte ratios) and assessed health condition in a wild koala population one year after a major translocation of bushfire-rescued koalas on Kangaroo Island. We expected to find a high population density at the site (>0.75 koalas per hectare) and that resident koalas would show signs of chronic stress and ill health as a result of territorial conflict over food trees and reproductive opportunities. In contrast, we found that only one-fifth of the population remaining at the site were translocated koalas. The overall population density was also much lower (0.21 koalas per hectare) than anticipated. With no evidence of mass mortality at the site, we suggest that the majority of translocated koalas dispersed away from the site. Our stress marker measurements did not differ between the wild koalas and a sample of captive (non-display) koalas at the nearby Kangaroo Island Wildlife Park and were generally low compared to other studies. Veterinary examinations found that most koalas were in good body condition with very few diagnostic indicators of systemic ill health. Overall, our results suggest that, if there is adequate landscape-scale habitat connectivity and opportunity for dispersal, translocated koalas are likely to disperse from the site of release, with limited impacts on recipient koala populations at translocation release sites.

Assessing neophobia and exploration while accounting for social context: an example application in scimitar-horned oryx

Spatial neophobia and exploration are often assessed in nonhuman animals by measuring behavioral responses to novel environments. These traits may especially affect the performance of individuals translocated to novel environments for conservation purposes. Here, we present methods to administer and analyze a minimally invasive novel environment test that accounts for the social context of focal individuals. We used an aerial platform to capture video footage of a captive herd of scimitar-horned oryx (Oryx dammah) entering an unfamiliar enclosure. We analyzed footage for seven individually identifiable oryx, scoring their behavioral responses (i.e., latency to enter the enclosure, and movement and posture after entering the enclosure) and social context (i.e., relative position and number of nearby animals). We performed a principal components analysis (PCA) to explore individual traits and responses, and used generalized linear mixed models (GLMMs) to determine the effect of individual traits and social context on individual posture and movement behaviors. Both PCA and GLMMs supported our expectation that social context affects individual behavior: high neighbor density and relative position were negatively related to individual movement, and variation in social context was positively related with head-up postures and movement. Oryx were well differentiated along two principal components that reflected (1) vigilance or caution, and (2) changing social context and age. These methods provide a framework for assessing individual responses to a novel environment in a group setting, which can inform reintroduction and wildlife management efforts, while minimizing interference with animal behavior and management operations.

Hatchery and wild larval lake sturgeon experience effects of captivity on stress reactivity, behavior and predation risk

Reintroduction programs are important tools for wildlife conservation. However, captive rearing environments may lead to maladaptive behavior and physiological alterations that reduce survival probability after release. For captive rearing programs that raise individuals captured from the wild during early ontogeny for later release, there is a lack of information about when during ontogeny the detrimental effects of captive rearing may become evident. In this study we compared cortisol levels, predation rates and swimming behavior between hatchery-produced and wild-caught larval lake sturgeon (Acipenser fulvescens), a threatened fish species, at three times over 9 days. Cortisol levels did not indicate that hatchery-produced individuals were more stressed, but cortisol reactivity to an acute stressor disappeared for both hatchery-produced and wild-caught larvae after 9 days in the hatchery. Swimming activity levels decreased over time for hatchery-produced larvae but increased over time for wild-caught larvae, suggesting that behavioral trajectories may be programmed prior to the larval stage. Neither increasing nor decreasing activity levels was advantageous for survival, as predation rates increased over time in captivity for larvae from both treatments. Results suggest that physiological and behavioral phenotypes may not accurately predict survival for individuals released from reintroduction programs and that the captive environment may inhibit transition to the wild even if cortisol levels do not indicate high stress. Findings emphasize that even a short amount of time in captivity during early ontogeny can affect phenotypes of individuals captured from wild populations, which may impact the success of reintroduction programs.

Island of misfit tortoises: waif gopher tortoise health assessment following translocation

Translocation, the intentional movement of animals from one location to another, is a common management practice for the gopher tortoise (Gopherus polyphemus). Although the inadvertent spread of pathogens is a concern with any translocation effort, waif tortoises-individuals that have been collected illegally, injured and rehabilitated or have unknown origins-are generally excluded from translocation efforts due to heightened concerns of introducing pathogens and subsequent disease to naïve populations. However, repurposing these long-lived animals for species recovery is desirable when feasible, and introducing waif tortoises may bolster small populations facing extirpation. The objective of this study was to assess the health of waif tortoises experimentally released at an isolated preserve in Aiken County, SC, USA. Our assessments included visual examination, screening for 14 pathogens using conventional or quantitative polymerase chain reaction (qPCR) and haematological evaluation. Of the 143 individuals assessed in 2017 and 2018, most individuals (76%; n = 109 of 143) had no overt clinical evidence of disease and, when observed, clinical findings were mild. In both years, we detected two known tortoise pathogens, Mycoplasma agassizii and Mycoplasma testudineum, at a prevalence of 10.2-13.9% and 0.0-0.8%, respectively. Additionally, we found emydid Mycoplasma, a bacterium commonly found in box turtles (Terrapene spp.), in a single tortoise that showed no clinical evidence of infection. The presence of nasal discharge was an important, but imperfect, predictor of Mycoplasma spp. infection in translocated tortoises. Hemogram data were comparable with wild populations. Our study is the first comprehensive effort to assess pathogen prevalence and hemogram data of waif gopher tortoises following translocation. Although caution is warranted and pathogen screening necessary, waif tortoises may be an important resource for establishing or augmenting isolated populations when potential health risks can be managed.

Rise and fall: Results of a multidisciplinary study and 5-year long monitoring of conservation translocation of the European ground squirrel

The current publication gives a detailed assessment of the results from a population reinforcement of a European ground squirrel's (Spermophiluscitellus) colony in south-eastern Bulgaria. The reinforcement was planned and implemented along with multidisciplinary research of the adaptation process (including radiotelemetry, parasitological study and assessment of the stress in the animals) and regular monitoring (yearly burrow counting). Although the donor and recipient populations were genetically similar, morphometrical data indicated variations in the body size probably due to the difference in population densities in the two sites. The monitoring revealed that the burrows were aggregated and there was a positive correlation in the spatial distribution of the ground squirrels' burrow holes and the colonies of Harting's vole (Microtushartingi) - another social ground-digging rodent that co-inhabits the study area. The first results showed successful reinforcement according to the three classical evaluation criteria: the individuals survived the translocation process, they successfully reproduced and an initial population growth was observed, based on the burrow entrances' count - from 36 in 2017 to 280 in 2020. In 2021, however, a considerable decline in the abundance of the population was recorded - 58.5% decline in the burrow number and 36% decline in the colony area. A decrease was also observed in the abundance of the Harting's voles' colonies. A review of all the collected information suggests it is unlikely that the decrease is due to helminth parasites, translocation stress or other behaviour issues. The most probable explanation is the bad weather conditions - unusually high rainfalls combined with relatively high temperatures in January 2021. In conclusion, we strongly emphasise the need for detailed and long-term monitoring after conservation translocation and careful evaluation of all the influencing factors before, during and after such actions.

Influence of weather on the behaviour of reintroduced Przewalski’s horses in the Great Gobi B Strictly Protected Area (Mongolia): implications for conservation

Background

Reintroduction is a common technique for re-establishing threatened species. However, the adaptation to novel habitats with distinct conditions poses a risk of failure. Weather conditions affect the behaviour of animals, and thus, their adaptation to new conditions and survival. Reintroduced Przewalski’s horses living in Mongolia’s continental arid climate with extreme temperature and precipitation variability, serve as an ideal model species for studying the behavioural response of selected groups to these harsh conditions.

Methods

The research was conducted in The Great Gobi B Strictly Protected Area, Mongolia. In summer 2018, three groups were recorded (Azaa, Tsetsen and Mares18) involving 29 individuals. In Spring 2019, 4 groups were recorded (Azaa, Tsetsen, Hustai1 and Mares19) involving 34 individuals. In Autumn 2019, 4 groups were recorded (Azaa, Tsetsen, Hustai2 and Tanan) involving 35 individuals. Thirteen weather variables were recorded in 10-min intervals, together with the percentage representation of selected behavioural categories (feeding, locomotion, resting, and social). The effect of weather on behaviour was analysed through GLMM. Influence of the group-history factors (recently reintroduced, long-term reintroduced and wild-born) was also analysed.

Results

Feeding significantly increased with cloudy and windy conditions and was more frequent in autumn than spring and summer. Locomotion was positively explained by temperature and cloudiness and was higher in summer than spring and autumn. Resting behaviour decreased with altitude and cloudiness, and the dispersion of the group was lower when resting. Increased social interactions were observed with higher temperatures and were more frequent in summer compared to spring and autumn. Differences were found in the display of the behaviours among the selected harems, showing interesting patterns when grouping them according to their origin and experience.

Conclusions

Weather patterns seem to influence the behaviour of Przewalski’s horse. These results might assist in further management plans for the species, especially in the view of intensifying climate change and alteration of weather patterns. As previously suggested, after approximately 1 year, horses adapt to novel conditions and display the typical behavioural pattern of wild-born Przewalski’s horses.

Post-release growth of captive-reared Gharial Gavialis gangeticus (Gmelin, 1789) (Reptilia: Crocodilia: Gavialidae) in Chitwan National Park, Nepal

Supplementation of wild populations of the Critically Endangered Gharial Gavailis gangeticus with individuals reared in captivity is a widely used conservation management tool in Nepal and India, although its efficacy is uncertain.  Measuring post-release growth in Gharial can provide valuable information on acclimation of captive-reared Gharial to the wild and provide growth rates to inform population recovery models.  We studied post-release growth of Gharial reared in the Gharial Conservation Breeding Centre, Nepal, following their release into the Chitwan National Park.  We used recapture data from known individuals to determine growth and change of mass for 26 Gharial recaptured 0.5–10 years after release. We found that Gharial recaptured two or more years post-release had increased in mass and length despite being over six years old at release, however there was a triangular relationship between time since release and growth: some Gharial had grown very slowly, whilst others had grown much faster.  All Gharial recaptured less than two years since release had lost mass and had negligible growth in total length. This data show that there is considerable variation in post-release growth rates, which will lead to some individuals being very old before they reach a potentially mature size class, with unknown implications for reproduction.  This variation is important for predicting or modelling recovery in populations where the release of Gharial from captivity is a management tool.  Our results also suggest the two years after release are an acclimation phase—when Gharial lose mass and do not grow—which should be considered by release strategies in order to give Gharial the best chance of survival after release.  

Developing welfare parameters for African elephants (Loxodonta africana) in fenced reserves in South Africa

South Africa has many fenced reserves harbouring small to medium sized populations of African elephant (Loxodonta africana), most of which have been translocated. Elephants on fenced reserves may be exposed to various management interventions and practices (translocation, hunting, darting, high tourism impact, contraception programs, disruption due to infrastructure maintenance, etc.). These factors may impact the welfare of elephants. Poor elephant welfare may have serious consequences such as increased inter- and intra-species aggression that could result in fatalities. This is the first study to attempt to define behavioural and physiological welfare parameters for free-ranging elephants on small to medium sized reserves. The eight study sites incorporated reserves with different social structure combinations, elephant life-histories, reserve sizes, habitat, management, and tourism intensity. Data collection consisted of behavioural observations (10-minute videos) as well as faecal samples. By incorporating both behavioural and physiological (faecal glucocorticoid metabolite (fGCM) concentration) parameters, we aimed to investigate whether the two parameters showed similar trends. Five behavioural categories were identified (Arousal, Assessing, Ambivalent, Ambivalent/ Body care, and Frustrated behaviour), with various detailed behaviours demonstrated by the elephants that may indicate the influence of anthropogenic disturbance and possibly impact on animal welfare. The study showed significant differences between the selected detailed behaviours, behavioural categories and fGCM concentrations of elephants across the eight reserves. History seemed to be a decisive factor, as reserves with predominantly ex-captive elephants showed higher frequencies of certain behaviours as well as higher fGCM concentrations. Age, sex, reserve size and season were also found to contribute to our defined welfare indices and fGCM concentrations. This indicates that behavioural parameters, indicative of certain behavioural states, are valuable indicators of welfare, as supported by the physiological response of the elephants. The results also highlight the importance of taking multiple specified behaviours from a category into consideration when evaluating the welfare of elephants, to account for individual variation.

Physiological acclimation of elk during population restoration in the Missouri Ozarks, USA

Conservation translocations-the intentional movement of animals to restore populations-have increased over the past 30 years to halt and reverse species declines and losses. However, there are many challenges translocated animals face that should be considered for restoration programs to be successful. Understanding how long it takes for translocated animals to acclimate to these challenges and their new landscape is a critical component of post-release population management. Physiological measures such as hormone responses are increasingly used to assess animal responses and acclimation to disturbances including translocation. We determined the physiological acclimation period of elk (Cervus canadensis) translocated to the Missouri Ozarks, USA, as part of a restoration effort. From 2011 to 2013, we translocated 108 GPS-radio-collared elk from Kentucky, USA, to Missouri, USA, and collected faecal samples for glucocorticoid metabolite extraction to use as an indicator of physiological acclimation. We modelled the response of population-wide faecal glucocorticoid metabolites (fGCMs) across the initial 9 years of the restoration in response to days following release and additional site-specific covariates. Presence of white-tailed deer (Odocoileus virginianus) hunts and monthly precipitation levels were positively and negatively associated with fGCM levels, respectively. Concurrent with influences from site-specific conditions on the release landscape, fGCM levels declined following release. We identified a breakpoint in fGCM decline at ~42 days following translocation releases suggesting elk acclimated physiologically relatively quickly compared to other species. The fast physiological acclimation by Missouri elk suggests effective use of temporary post-release management efforts. Determining how quickly animals acclimate following translocations allows researchers to tailor post-release management plans to each species' needs, thus maximizing the success of future translocation efforts while minimizing costs.

Physiological Health and Survival of Captive-Reared and Released Juvenile Blanding's Turtles

AbstractConservation translocations are important in maintaining viable wildlife populations of vulnerable species within their indigenous ranges. To be effective, population restoration efforts (e.g., head start programs) must consider the species' life history, regional ecology, and physiology and the health status of wild and translocated populations. The decline of Blanding's turtles (Emydoidea blandingii) has prompted the initiation of head start programs, but the health and short-term survival of head-started juveniles released to the wild is largely unknown. From May to October 2016 and 2017, we radio tracked captive-reared, recently released juvenile Blanding's turtles and monitored their survivorship and monthly physiological health. We aimed to (1) compare physiological metrics of juveniles before and after release from captivity and between head-started cohorts, (2) identify seasonal trends in physiological metrics of recently released juveniles, (3) compare physiological metrics of recently released and formerly released juveniles, and (4) identify predictors of juvenile survivorship after release from captivity. Juvenile short-term survival was low compared with other studies. Most physiological metrics did not change after release from captivity, negating significant juvenile stress before or after release. Physiological metrics for recently released cohorts varied seasonally, suggesting that these juveniles were likely in good health. Some physiological metrics differed between recently released and formerly released juveniles, demonstrating a potential postrelease acclimatization period. Finally, no physiological metrics significantly predicted survival, but surviving juveniles had a higher percentage of fat. In all, juvenile deaths were not due to poor turtle health but rather to predation from human-subsidized mesocarnivores. Therefore, head-started juvenile Blanding's turtles released in suburban areas may benefit from antipredator training and mesocarnivore control at release sites.

Novel Conditions in Conservation Translocations: A Conservative-Extrapolative Strategic Framework

In response to anthropogenic threats, conservation translocations are increasingly used to combat species' population and range declines. However, moving animals outside of their current distribution can mean introducing them to novel conditions, even in the case of reintroductions to formerly inhabited areas due to ecosystem changes following extirpation. This exposure to novel conditions introduces uncertainty that can undermine decision making for species conservation. Here we propose two strategies, which we define as conservative and extrapolative, for approaching and managing novelty and the resulting uncertainty in conservation translocations. Conservative strategies are characterised by the avoidance and removal of novel conditions as much as possible, whereas extrapolative strategies are more experimental, allowing exposure to novel conditions and monitoring outcomes to increase understanding of a species' ecology. As each strategy carries specific risks and opportunities, they will be applicable in different scenarios. Extrapolative strategies suit species in recovery which can afford some experimental management, or species facing novel and emerging threats which require less traditional translocations, such as assisted colonisations. We provide examples, applying our framework to two endemic New Zealand species with long histories of translocation management: tuatara (Sphenodon punctatus), a reptile and takahē (Porphyrio hochstetteri), a flightless bird.

Social networks research in ex situ populations: Patterns, trends, and future directions for conservation-focused behavioral research

Social networks research using non-human animals has grown over the past decade, utilizing a wide range of species to answer an array of pure and applied questions. Network approaches have relevance to conservation, evaluating social influences on fecundity, health, fitness and longevity. While the application of network approaches to in situ populations with conservation concern appears in published literature, the degree to which ex situ and zoo-housed populations are the focus of "social networks for conservation research" is limited. Captive environments provide scientists with an ability to understand the social behavior of species that may be hard to observe consistently in the wild. This paper evaluates the scope of network research involving ex situ populations, analyzing output from 2010 to 2019 to determine trends in questions and subjects using ex situ populations. We show that only 8.2% of ex situ social network analysis (SNA) implications are of conservation-focus, apparent in papers relating to birds, carnivores, bats, primates, reptiles, and ungulates. Husbandry and welfare questions predominate in ex situ network research, but over half of these papers have nonpractical application (basic science). The chance of a citation for a basic science paper was 95.4% more than for a conservation-based paper. For taxonomic groups, primate-focused papers had the most citations. The focus of ex situ conservation-based networks research may be driven by the needs of conservation programs (e.g., population recovery outcomes) or by a need to evaluate the efficacy of ex situ conservation goals. We evaluate our findings considering the IUCN's One Plan Approach to conservation to show how in situ and ex situ network research is applicable to global conservation efforts. We have identified that there is a lack of application and evaluation of SNA to wildlife conservation. We highlight future areas of research in zoos and hope to stimulate discussion and collaboration between relevant parties.