Elephant endotheliotropic herpesviruses (EEHVs) may cause acute, often lethal, hemorrhagic disease (EEHV-HD) in young elephants. Prevalence of EEHV in different elephant populations is still largely unknown. In order to improve diagnostic tools for the detection of EEHV infections and to obtain insight into its spread among elephants, we developed novel ELISAs based on EEHV1A gB and gH/gL. Performance of the ELISAs was assessed using sera from 41 European zoo elephants and 69 semi-captive elephants from Laos, one of the Asian elephant range countries. Sera from all (sub)adult animals tested (≥5 years of age) showed high reactivity with both gB and gH/gL, indicating that EEHV prevalence has been highly underestimated so far. Reactivity towards the antigens was generally lower for sera of juvenile animals (1 > 5 years). Only one (juvenile) animal, which was sampled directly after succumbing to EEHV-HD, was found to be seronegative for EEHV. The two other EEHV-HD cases tested showed low antibody levels, suggesting that all three cases died upon a primary EEHV infection. In conclusion, our study suggests that essentially all (semi-)captive (sub)adult elephants in European zoos and in Laos carry EEHV, and that young elephants with low antibody levels are at risk of dying from EEHV-HD.

The interactions between wild and captive populations of Asian elephants (Elephas maximus) persist in most countries of the species distribution, notably through the reproduction between captive females and wild males. However, these complex interactions have been poorly studied, despite their relevance for conservation of this endangered species. Laos has a centuries-long tradition of raising Asian elephants. Besides being cultural icons, captive elephants are inextricably linked to economics through their work in forestry. Using an ecological-economic model, we investigated the effect of socio-economic strategies on fecundity of the Lao population whose dynamics is shaped by human practices. We demonstrated that fecundity is impacted by: i) the dynamics of the wild elephant pool through mating of captive females by wild males, and ii) the financial incentive of elephant owners to breed their animals. As a result, we expect fecundity to rise in response to increases in elephant prices. The captive population will tend towards an asymptotic limit determined by the wild pool growth rate. However, the population will tend to extinction if exports continue. Our ecological-economic approach, by accounting for economic incentives, allows us to predict new equilibria that can serve as a baseline for designing sustainable management strategies for the species.

Few empirical studies have described social‐ecological systems (SESs) in transition. Some studies focused on external drivers that impact the SES and communities' responses to adapt to changes, including economic, land and conservation policies. Others have considered the effect of social and cultural changes on communities' capacity to sustain their activities. While sociocultural changes are increasingly common through globalization and world‐wide economic development, there is an urgent need to better understand and document how these changes affect individual and community agency to adapt or transform a system that is facing a combination of powerful internal and external forces. The human–Asian elephant relationship appears particularly illustrative of a complex SES because of the dual status of the elephant being wild or under human care, and the entanglement of ecological, cultural, social and economic dimensions. The ongoing and rapid political, socio‐economic and environmental changes occurring in Laos for the last decades have strongly affected this relationship. We conducted an ethnological survey to assess how the SES has evolved in Laos and its consequences for human‐wild‐captive elephant interactions and elephant handling practices. We show that in the 1990s, the SES was based on the principles of common access to natural resources and social control over nature and spirits, and led to a form of elephant handling with close interactions between captive and wild elephants. Husbandry practices then could be likened to pastoralism as a mode of production associated with a mode of relation close to seasonal freedom. Since the turn of the present century, the commodification of nature and of increasingly divided access to natural resources led eventually to the segregation of wild elephants and captivity of their working conspecifics. With the intensification of workload, owners switched to a ranching‐like economy, based on the accumulation of monetary capital from the employment of elephants in logging or tourism. We discuss how the combination of external drivers, such as economic liberalization, land and conservation policies, and internal drivers linked to sociocultural changes could affect a SES in transition, leading to a fading interest of the new generation in their family heritage. A free Plain Language Summary can be found within the Supporting Information of this article.

Wild species living in captivity are subject to loss of genetic diversity, inbreeding depression, and differentiation among populations. Only very few species have been under human care for centuries but have not been selectively bred, have free-ranging movements most of the time, and retain porous barriers to gene flow between wild and captive populations. Such captive populations are expected to retain high levels of genetic diversity and anthropogenic factors should result in a limited genetic differentiation from wild populations. Asian elephants have been trained and used by humans for at least 4000 years as war animals, mounts of kings and draught animals. In Myanmar and Laos, elephants are still being used for hauling timber in the forest while retaining traditional management practices including seasonal release, free mating and movement. However, habitat fragmentation, isolation and reduced gene flows are threatening both semi-captive and wild pools. We genotyped 167 semi-captive elephants from Laos and Myanmar using a panel of 11 microsatellite loci to estimate the genetic diversity and population structure. We found that elephants of both countries presented high levels of genetic diversity and a low degree of inbreeding, if any. This agrees with the expected high level of genetic diversity in semi-captive populations. We found a weak differentiation along a geographical gradient from southern Laos to northern Myanmar but no differentiation between wild-caught and captive-born pools. The potential value for conservation of a large population of semi-captive elephants has been recognized but the conservation community has yet to fully explore the potential role semi-captive elephants could play in maintaining gene flows.

Depuis des millénaires, l’éléphant d’Asie joue un rôle important dans la culture, l’économie et la construction des pays asiatiques. Près d’un quart de la population de cette espèce emblématique et menacée est constituée d’éléphants dits captifs. Toutefois, les législations nationales comme les programmes de conservation ont tendance à traiter séparément les populations captives et sauvages. Au Laos et au Myanmar, la tradition d’élevage par les villageois et les interactions entre éléphants sauvages et éléphants de villages perdurent.L’objectif de cette thèse est de qualifier et quantifier ces interactions afin de mieux comprendre leurs dynamiques et leurs rôles dans la survie de l’espèce. Je me suis attaché à décrire les facteurs déterminant le système socio-écologique humain - éléphant de village - éléphant sauvage et sa résilience à travers une approche interdisciplinaire et intégrative.Une étude ethnoécologique a permis d’analyser l’évolution récente du système socio-écologique homme-éléphant au Laos et ses conséquences sur les relations humain-éléphant, les pratiques d’élevage et la perception de l’espèce chez les propriétaires d’éléphants. L'émergence depuis les années 2000 de la marchandisation de la nature et de la restriction de l'accès aux forêts a conduit, d’une part, à la ségrégation entre éléphants sauvages et éléphants de villages, et d’autre part, à l’intensification de l'élevage de ces derniers. Or, la tolérance des communautés à la présence des éléphants sauvages semble liée au principe de réciprocité. Ainsi, les propriétaires ayant accès aux mâles sauvages pour féconder leurs femelles acceptent leur présence contrairement aux cornacs engagés dans le débardage du bois.J’ai ensuite construit un modèle bio-économique pour quantifier les effets des stratégies socio-économiques sur la viabilité à long terme de la population d’éléphants de villages du Laos. J’ai montré que la fécondité est impactée en premier lieu par la dynamique de la population sauvage à travers la reproduction entre femelles de villages et mâles sauvages. En second lieu, le taux de fécondité dépend de l’intérêt financier des propriétaires à faire de la reproduction. Ainsi la viabilité de la population est fortement dépendante des conditions socio-économiques sur le court terme et de l’efficience de la conservation des populations sauvages sur le long terme.Une étude de génétique des populations a montré que la diversité génétique des populations sauvages et de villages était élevée et que ces populations constituaient un ensemble homogène au Laos et au Myanmar. L’isolement des populations sauvages et la ségrégation croissante des populations de villages engendreront un appauvrissement génétique sur le long terme qu’il est possible de limiter par des mesures de gestion favorisant le flux de gènes au niveau régional et entre les deux populations, notamment en les considérant comme une unité de gestion commune.Ces deux études illustrent que la résilience du système socio-écologique est la résultante de multiples facteurs agissant à différents niveaux ou échelles, dont les effets sont parfois opposés.Cette thèse permet enfin de discuter des conditions de la résilience et de la viabilité à long terme du système socio-écologique humain-éléphant et d’explorer différents scénarios futurs en s’interrogeant également sur le possible processus de domestication de l’espèce.

Opportunities for direct experience with wildlife shape human perceptions and behaviors, influencing human-environment relationships. These perceptions vary across communities according to lived experiences and the assessed costs and benefits of living with wildlife. In a changing global context, a “perception-practice loop” emerges, where shifts in local practices directly affect attitudes toward wildlife. This study uses a mixed-methods approach - combining qualitative and statistical analysis of semi-structured interviews - to examine how evolving elephant handling practices in Laos influence direct interactions with and perceptions of wild elephants. Our findings indicate that owners adapt their strategies to diverse socio-ecological contexts driven by recent global pressures. These practices, often grounded in reciprocity, shape perceptions and levels of tolerance toward wild individuals. The results indicate that tolerance depends less on aggressive elephant behavior and more on the perceived balance of costs and benefits. While wild elephants impose psychological or delayed burdens, they also provide tangible and symbolic benefits, such as mating opportunities and conservation value. We conclude that fostering reciprocal relationships and integrating traditional knowledge can enhance human-wildlife coexistence, supporting both biodiversity and local well-being.