Olivier Lourdais

• PhD
• Researcher at French National Centre for Scientific Research

Les reptiles sont particulièrement exposés à la dégradation des habitats à une échelle mondiale et sont encore victimes de biais de perception et de méconnaissance. Les travaux récents montrent l’importance des microhabitats pour les reptiles notamment dans le contexte de l’intensification des pratiques des changements climatique en cours. Le fort...

Les reptiles sont particulièrement exposés à la dégradation des habitats à une échelle mondiale et sont encore victimes de biais de perception et de méconnaissance. Les travaux récents montrent l’importance des microhabitats pour les reptiles notamment dans le contexte de l’intensification des pratiques des changements climatique en cours. Le fort...

Metallic trace elements (MTEs) constitute a major source of chemical pollution and represent a threat to aquatic ecosystems and organisms. Important variation in contamination may exist at a local scale in relation to the environment (hydrosystem, trophic ressources) and individual traits (age, sex). Heretofore, the factors influencing MTEs exposur...

The Western Montpellier snake (Malpolon monspessulanus) is the only snake species known in France to be regularly active in winter. Although its behaviour has been known for a long time, there are no specific studies on the scale of its distribution area. In order to understand the determinants of these outings, we counted individuals at a hibernat...

Présentation réalisée lors de l'hommage à Guy Naulleau à l'occasion du 51ème Congrès de la Société Herpétologique de France (SHF) à Carcassonne du 23 au 26 Octobre 2024. En France, au XIXème siècle, les départements des Deux-Sèvres (79) et de la Vendée (85) étaient parmi les plus concernés par la présence de la Vipère aspic Vipera aspis, (Linnaeus...

Les paysages bocagers abritent de nombreuses espèces de reptiles qui utilisent les haies et les lisières à la fois pour thermoréguler et s’abriter. Ces paysages subissent depuis plusieurs décennies de fortes dégradations du fait des modifications des pratiques agricoles. La Réserve Naturelle Régionale du bocage des Antonins, localisée dans le dépar...

To minimize predation risk and the cost of confronting predators, prey have developed a range of defensive strategies and warning signals. Although advantageous, defensive warnings may also induce physiological and energy costs to the emitter. Ventilatory sounds (hissing) are the most distributed warning sound in vertebrates. Because they involve t...

Infectious diseases are influenced by interactions between host and pathogen, and the number of infected hosts is rarely homogenous across the landscape. Areas with elevated pathogen prevalence can maintain a high force of infection and may indicate areas with disease impacts on host populations. However, isolating the ecological processes that res...

The regulation of energy, water and thermal balance involves integrated processes that should drive ecological responses of ectotherms to climate change. Functional tradeoffs between thermoregulation and hydroregulation are exacerbated during hot or dry spells, but how microhabitat hydric properties and trophic resource availability influence these...

Aim Ecological niche‐based models (ENM) frequently rely on bioclimatic variables (BioV) to reconstruct biogeographic scenarios for species evolution, ignoring mechanistic relations. We tested if climatic predictors relevant to species hydric and thermal physiology better proximate distribution patterns and support location of Pleistocene refugia de...

Nocturnal temperatures are increasing at a pace exceeding diurnal temperatures in most parts of the world. The role of warmer nocturnal temperatures in animal ecology has received scant attention and most studies focus on diurnal or daily descriptors of thermal environments' temporal trends. Yet, available evidence from plant and insect studies sug...

Species may respond to climate change by redistributing their distribution areas, but because they do not share the same climatic affinities, they should not respond in the same way. Consequently, distribution shifts of species that are currently found in sympatry may change the extent of the area of sympatry and therefore interspecific inter...

Wetlands are among the most threatened ecosystems on the planet and pollution is a major factor causing the decline of wetland biodiversity. Despite the increasing use of pesticides, their fate and effects on freshwater reptiles remain largely unknown. We studied the European pond turtle (Emys orbicularis), a long-lived species at risk with a high...

Les paysages bocagers sont largement répandus en France. Eléments constitutifs de ces paysages, les haies et les boisements abritent régulièrement des trognes, appelées également arbres têtards et issus de pratiques traditionnelles. Quand ils sont âgés, ces arbres ont des rôles écologiques majeurs. Ils sont ainsi considérés comme des arbres-habitat...

In many taxa, natural selection favours the ability of a female to accommodate a clutch or litter that is very large relative to her own body, placing a selective premium on traits that increase available abdominal space relative to litter volume. Flexible changes during pregnancy might help to mitigate these constraints. Using ultrasound scanning...

To cope with limited availability of drinking water in their environment, terrestrial animals have developed numerous behavioral and physiological strategies including maintaining an optimal hydration state through dietary water intake. Recent studies performed in snakes, which are generalist carnivorous reptiles, suggest that benefits of dietary w...

Aim Allopatric speciation is the primary mode of diversification in the Mediterranean Basin. However, the contribution of climatic adaptation during this process is contradictory. In this work, we investigate the eco-evolutionary processes that drove diversification in this region, using European vipers as a case study. We describe the climatic req...

Optimal regulation of body temperature and water balance is essential for the survival of terrestrial ectotherms in a changing world. A behavioural trade-off exists between these two constraints because maintaining a high body temperature usually increases evaporative water losses. In addition, the evaluation of predation risk is a key factor in be...

In Western Europe, natural habitats such as heathlands have been converted into many commercially managed forests, with severe impacts on biodiversity. In dense planted forests, forest edges are often the only suitable areas for ectothermic organisms highly dependent on open habitats for thermoregulation. Surprisingly, the influence of forest edges...

Previous studies on viper bites in France have focused on clinical consequences of envenomation, efficacy of antivenom and epidemiology of bites. Herein, we wanted to clarify temporal and spatial patterns in bite incidence using a fine spatial scale (municipality level). We focused on viper bites recorded over the last 10 years in 4 regions of west...

During extreme climate events, behavioural thermoregulation may buffer ectotherms from thermal stress and overheating. However, heatwaves are also combined with dry spells and limited water availability, and how much individuals can behaviourally mitigate dehydration risks through microclimate selection remains largely unknown. Herein, we investiga...

1. Infectious diseases are influenced by interactions between host and pathogen, and are rarely homogenous across the landscape. Areas with elevated pathogen prevalence maintain a high force of infection, can facilitate pathogen spread to new regions, and may indicate areas with impacts on host populations. However, isolating the ecological process...

Thermo-hydroregulation strategies involve concurrent changes in functional traits related to energy, water balance and thermoregulation and play a key role in determining life-history traits and population demography of terrestrial ectotherms. Local thermal and hydric conditions should be important drivers of the geographical variation of thermo-hy...

Climate change will continue to increase mean global temperatures with daily minima increasing more than daily maxima temperatures. Altered rainfall patterns due to climate change will also disrupt water availability for terrestrial organisms already facing climatic warming. To explore how organisms may adjust to changes in multiple, concurrent cli...

Environmental conditions and maternal effects can have profound effects on offspring phenotypes in terrestrial ectotherms. In reptiles, only a few studies examined the effects of elevation and maternal body size on reproductive traits. In general, in lizards, clutch size increases with female body size. Geckos, however, have fixed clutch sizes (one...

In Western Europe, omnipresent human activities have considerable impacts on habitats at several spatial scales resulting in direct shifts in habitat characteristics. These modifications in habitat features can disrupt biotic interactions such as predation. Surprisingly, although snake species are facing a worldwide decline, relationships between h...

Les reptiles sont particulièrement vulnérables aux modifications des paysages et des habitats du fait de leur mobilité réduite et de leurs exigences thermiques et hydriques. De nombreuses espèces sont en déclin dans le monde et également en France. Des études récentes mettent en évidence l’importance des milieux bordiers pour leur conservation et l...

Aging is the price to pay for acquiring and processing energy through cellular activity and life history productivity. Climate warming can exacerbate the inherent pace of aging, as illustrated by a faster erosion of protective telomere DNA sequences. This biomarker integrates individual pace of life and parental effects through the germline, but wh...

Triazole compounds are among the most widely used fungicides in agroecosystems to protect crops from potential fungal diseases. Triazoles are suspected to have an impact on non‐target species due to their interactions with non‐fungal sterol synthesis and wild birds are likely to be contaminated by triazoles fungicides as many of them live in agroec...

Agricultural landscapes cover a large portion of the planet and the intensification of farming is a primary cause of biodiversity loss. Changes in agricultural practices have been particularly marked in Western Europe over the last century. Hedgerow landscapes consist of complex mosaics of pastures, ponds, and hedges connected with forest patches t...

Asp vipers ( Vipera aspis ) and adders ( Vipera berus ) coexist in the Loire-Atlantique department in France where the two species reach their respective range limits. This contact zone is of special interest since hybridization has been recently discovered there. We carried out extensive sampling to further investigate the hybrid status of morphol...

A historic debate in biology is the question of nature vs. nurture. Although it is now known that most traits are a product of both heredity (“nature”) and the environment (“nurture”), these two driving forces of trait development are rarely examined together. In birds, one important aspect of the early developmental environment is egg incubation t...

Parental thermoregulation can provide an efficient way to control embryonic temperature and optimize developmental durations and timing. To date, most studies on parental thermal effects have focused on maternal influences, because of the predominant role of females for parental care in most systems. Yet, paternal thermal effects are equally expect...

Heatwaves and droughts are becoming more intense and frequent with climate change. These extreme weather events often occur simultaneously and may alter organismal physiology, yet their combined impacts remain largely unknown. Here, we experimentally investigated physiological responses of a temperate ectotherm, the asp viper (Vipera aspis), to a s...

Nouvelle édition mise à jour avec les chants d'Anoures. Ce petite guide richement illustré de 115 photos et 70 illustrations, présente les 22 taxons d’Amphibiens et 14 espèces de Reptiles qu’il est possible d’observer dans les bocages de l’ouest et du nord ouest de la France. Il a pour vocation de mieux faire connaître ces espèces à un large publi...

Vertebrate skin regulates exchanges between the organism and its environment and notably plays a fundamental role in regulating water fluxes. Dynamic changes of skin resistance to water fluxes are expected to occur in species that regularly shift between habitat types especially if these habitats differ in their hydric properties (e.g., terrestrial...

Developmental plasticity and thermal acclimation can contribute to adaptive responses to climate change by altering functional traits related to energy and water balance regulation. How plasticity interacts with physiological syndromes through lifetime in long‐lived species is currently unknown. Here, we examined the impacts of long‐term thermal ac...

Le changement climatique conduit à des modifications graduelles des conditions thermiques et hydriques mais aussi favorise des évènements extrêmes plus intenses et plus fréquents. Alors que les effets des changements de température sur les organismes ectothermes sont classiquement étudiés, les effets combinés des stress thermiques et hydriques extr...

Les bocages sont des agroécosystèmes dont l’intérêt écologique est de plus en plus mis en évidence, notamment grâce à leur diversité d’habitats (écocomplexe) et leurs importants réseaux de haies qui jouent le rôle de corridors écologiques pour de nombreuses espèces, dont les reptiles. Ces animaux ectothermes sont particulièrement sensibles à l’agen...

Recent agricultural intensification threatens global biodiversity with amphibians being one of the most impacted groups. Because of their biphasic life cycle, amphibians are particularly vulnerable to habitat loss and fragmentation that often result in small, isolated populations and loss of genetic diversity. Here, we studied how landscape heterog...

Human activities have a major impact on habitat connectivity and landscape structure. In this context, it is critical to better understand animal movements and gene flow to develop appropriate conservation and land management measures. It is also important to better understand difference between sexes in space use and spatial scale of dispersal. We...

Droughts are becoming more intense and frequent with climate change. These extreme weather events can lead to mass mortality and reproduction failure, and therefore cause population declines. Understanding how the reproductive physiology of organisms is affected by water shortages will help clarify whether females can adjust their reproductive stra...

Motivation The understanding of physiological adaptations, of evolutionary radiations and of ecological responses to global change urges for global, comprehensive databases of the functional traits of extant organisms. The ability to maintain an adequate water balance is a critical functional property influencing the resilience of animal species to...

Many banned persistent organic pollutants (POPs) remain for decades in the aquatic environment and can have harmful effects on long‐lived predators because of their high bioaccumulation and biomagnification potentials. We investigated the occurrence and levels of 18 polychlorinated biphenyls (PCBs) and 16 organochlorine pesticides (OCPs) in Europea...

Aim: Determining whether altitudinal shifts in species distributions leave molecular footprints on wild populations along their range margins from rear to leading edge. Location: South-west France. Methods: We compared the demographic and genetic variation in 42 wild populations of the Western oviparous subclade B2 of a cold adapted lizard (Zooto...

Parental care is widespread across the animal kingdom. Parental behaviours are beneficial by increasing offspring survival but induce significant costs to the parents. Because parental care is much more represented in females, associated reproductive costs have been largely studied in this sex. While male parental care is likely to involve signific...

One of the greatest current threats to biodiversity is climate change. However, understanding of organismal responses to fluctuations in temperature and water availability is currently lacking, especially during fundamental life-history stages such as reproduction. To further explore how temperature and water availability impact maternal physiology...

The intensification of human activities is responsible for habitat loss which is the major cause of biodiversity regression. In this context, it becomes critical to consider with more attention highly transformed or artificial habitats that may have a significant value for biodiversity conservation. It is also equally important to evaluate the sign...

The designation of taxonomic units has important implications for the understanding and conservation of biodiversity. Eurasian vipers are a monophyletic group of viperid snakes (Serpentes, Viperinae), currently comprising four genera (Daboia, Macrovipera, Montivipera and Vipera) and up to 40 species. Taxonomic units have been described using a wide...

Parent-offspring conflicts are widespread in nature given that resources are often limited. Recent evidence has shown that water can trigger such conflict during pregnancy in viviparous squamate species (lizards and snakes) and thus questions the role of water in the evolution of reproductive modes. Here, we examined the impact of water restriction...

Most amphibians use both aquatic and terrestrial habitats. While the aquatic phase attracted considerable interest, terrestrial habitat use is often less investigated. We studied diurnal refuge selection in the Midwife toad in Western central France. We used a factorial design and tested the effect of refuge type (wood versus rubber boards) and sub...

Whole organism metabolism is an integrative process that determines not only the energy cost of living but also the energy output that is available for behavioral and physiological processes during the life cycle. Developmental challenge is known to affect growth, development of several organs, and several physiological mechanisms (such as HPA resp...

Les phases précoces du développement sont des étapes sensibles de la vie de l’organisme. Elles permettent la mise en place du phénotype et peuvent influencer à long-terme les traits d’histoire de vie. Les soins parentaux prénataux permettent de tamponner en partie les conditions environnementales et donc d’en réduire les impacts négatifs potentiels...

Abstract The regulation of body temperature (thermoregulation) and of water balance (defined here as hydroregulation) are key processes underlying ecological and evolutionary responses to climate fluctuations in wild animal populations. In terrestrial (or semiterrestrial) ectotherms, thermoregulation and hydroregulation closely interact and combine...

The evolution of sex determination is complex and yet crucial in our understanding of population stability. In ectotherms, sex determination involves a variety of mechanisms including genetic determination (GSD), environment determination (ESD), but also interactions between the two via sex reversal. In this study, we investigated whether water dep...

Depuis quarante ans, de nombreux inventaires et suivis ont été réalisés sur la Vipère péliade Vipera berus (Linné, 1758) dans l'ouest de la France. On constate un faible polymorphisme des individus ainsi qu'une grande rareté des spécimens mélaniques. Nous rapportons ici trois observations inédites d'individus fortement mélanisants à mélaniques et c...

Agricultural intensification is responsible for major habitat degradation and is a primary cause of biodiversity loss. Amphibians are currently facing a global decline induced by multiple pressures, including notably habitat degradation and land conversion. In western Europe, traditional farming systems involve a dense hedgerows network with a mosa...

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.

Amphibians are particularly sensitive to landscape fragmentation. Potential barriers between breeding sites can negatively influence the dispersal of individuals and increase genetic structure between populations. In this study, we genotyped 10 microsatellites for 334 marbled newts (Triturus marmoratus) at 11 different locations in Western France....

Early life stages are particularly vulnerable to environmental perturbations. Embryonic thermal sensitivity may be a driving force in the emergence of prenatal parental care like maternal thermoregulation. Viviparity has emerged on repeated occasions among squamate reptiles and two main evolutionary hypotheses based on maternal thermoregulation hav...

The use of fat to support the energy needs of reproduction (i.e. capital breeding) has been studied in a diversity of taxa. However, despite reproductive output (i.e. young or eggs) being approximately 70% water, little is known about the availability of internal resources to accommodate the hydric demands of reproduction. Recent research suggests...

Présentation lors d'une journée d’échanges techniques organisée par l'Agence Française pour la Biodiversité (AFB) dans le cadre du Centre de ressources Trame verte et bleue et en partenariat avec le ministère de la Transition écologique et solidaire et le ministère de l’Agriculture et de l’Alimentation. Lien web : http://www.trameverteetbleue.fr/vi...

Le Plan national d’action (PNA) en faveur du Lézard ocellé (Doré & Thirion, 2012) a été décliné au niveau des régions Provence-Alpes-Côte d’Azur et ex-Languedoc-Roussillon. Un Plan Inter Régional d’Actions (PIRA) spécifique à ces deux régions a été élaboré et mis en œuvre de 2013 à 2017 (Legouez & Marchand, 2013). Les résultats présentés ci-après...

Résumé - La compréhension des effets locaux du changement climatique sur la biodiversité est essentielle pour orienter les politiques de gestion des espaces naturels. Le manque de connaissances au niveau régional en Nouvelle-Aquitaine (sud-ouest de la France) a conduit au développement d’un programme de recherche « les sentinelles du climat » (sent...

The energy cost of self-maintenance is a critical facet of life-history strategies. Clarifying the determinant of interspecific variation in metabolic rate (MR) at rest is important to understand and predict ecological patterns such as species distributions or responses to climatic changes. We examined variation of MR in snakes, a group characteriz...

We examined the possible interaction between reproductive effort and embryonic stages at oviposition in oviparous form of the lizard Zootoca vivipara. Our results reveal that the percentage of total embryonic development time (%TEDT) reached at oviposition is negatively correlated to clutch size (adjusted to maternal body size). We found no influen...

Water constraints can mediate evolutionary conflict either among individuals (e.g., parent-offspring conflict, sexual conflict) or within an individual (e.g., cost of reproduction). During pregnancy, water is of particular importance because the female provides all water needed for embryonic development and experiences important maternal shifts in...

High levels of anthropogenic noise produced in urban areas are known to negatively affect wildlife. Although most research has been focused on the disturbances of communication systems, chronic noise exposure can also lead to physiological and behavioural changes that have strong consequences for fitness. For instance, behavioural changes mediated...

The physiological mechanisms underlying the 'cost of reproduction' remain under debate, though oxidative stress has emerged as a potential candidate. The 'oxidative cost of reproduction' has received considerable attention with regards to food and antioxidant availability, however the limitation of water availability has thus far been neglected. In...

The physiological mechanisms underlying the ‘cost of reproduction’ remain under debate, though oxidative stress has emerged as a potential candidate. The ‘oxidative cost of reproduction’ has received considerable attention with regards to food and antioxidant availability, however the limitation of water availability has thus far been neglected. In...

Western European vipers are well-defined species with parapatric distributions that reflect contrasting thermal niches and climatic adaptations. Contact zones are usually narrow, coincide with steep ecological gradients and are associated with clear habitat segregation. Natural hybridization has been demonstrated between several species but has not...

In Europe, the recent agricultural intensification has strongly homogenised the landscape. This loss in habitat diversity and the use of agrochemicals are considered as major causes of the global erosion of biodiversity. Landscape changes may also favour phenotypic variation with divergences between populations even at a small spatial scale. We inv...

Temperature plays a crucial role for ectotherm performance and thus for fitness. Terrestrial ectotherms, including reptiles, regulate their body temperature mainly by behavioural means. At high altitude, however, thermal constraints make precise thermoregulation costly. The cost-benefit model of lizard thermoregulation predicts that thermally chall...

Migration is an important event in the life cycle of many organisms, but considerable intraspecific variation may occur in its timing and/or destination, resulting in sexual segregation during wintering periods. In this study, we tested the body size hypothesis, or cold tolerance hypothesis, which predicts that body size dimorphism modulates metabo...

Circulating glucocorticoids (GCs) levels may increase as a result of reproductive effort or in response to unpredictable events. However, the GCs secretion can vary with the availability of vital trophic resources such as energy. While water represents another critical resource, the impact of water deprivation on GCs secretion during reproduction h...

Traditional farming landscape in western Europe is made of a complex mosaic of pastures, cultures, ponds and hedgerows connected with woods. Previous observations in the common frog species suggest that lowland populations are closely associated to wood cover and our aim was to test the validity of this assumption. We studied common frog occurrence...