Decline of a Hermann’s Tortoise (Testudo hermanni hermanni Gmelin, 1789) population in forest. Combined effects of several anthropogenic factors

This study investigates the evolution of a population of Hermann’s tortoises, located on the edge of the massif des Maures, over a period of 30 years through capture–recapture monitoring. It shows a considerable decline of 73 % in the number of adult tortoises between the early 1980s and 1999; then from 1999, the population stabilized at around 100 adult tortoises. The fall in numbers during the first period seems to be linked to several factors. The 22 % increase in forest cover between 1983 and 1995 increased the concentrations of eggs laid in some open areas, making it easier for the species’ natural predators to find them. Mechanized clearance of undergrowth carried out in 1989 and 1994 has undoubtedly reduced the size of the population. The presence of dogs has posed an additional threat (97 % of the adult tortoises have bite marks and 7 % are missing limbs). In addition, the impact of dog bites on the tortoises’ shells has, over time, removed individual markings, thereby distorting survival estimates. The stabilization of numbers over the last decade seems to be due to the discontinuation of certain practices (notably mechanized undergrowth clearance). However, the demographic structure (with almost no juveniles) could soon lead to another decrease in population. This situation seems to be specific to this particular population and cannot be applied generally to all the populations in ProvenceCette étude analyse l'évolution d'une population de Tortue d'Hermann située en marge du massif des Maures sur une période de 30 années, sur la base de suivis par capture―recapture. Elle montre une baisse considérable des effectifs adultes (73 %) entre le début des années 1980 et 1999, puis une stabilisation de la population aux alentours de 100 individus adultes à partir de 1999. Cette chute des effectifs sur la première période semble liée à une addition de facteurs. L'augmentation de 22 % du couvert forestier entre 1983 et 1995 accroît la concentration des pontes sur quelques zones ouvertes, ce qui favorise leur découverte par les prédateurs naturels de l'espèce. Des débroussaillages mécaniques conduits en 1989 et 1994 ont certainement amoindri les effectifs de la population. La pression exercée par les chiens (actuellement 97 % des sujets adultes présentent des traces de crocs et 7 % des amputations de membres) vient ajouter une menace supplémentaire. De plus, les impacts de crocs de chien sur les carapaces de tortues ont provoqué une perte des marques individuelles au cours du temps, biaisant ainsi les estimations de survie. La stabilisation des effectifs depuis une dizaine d'années semble due à l'arrêt de certaines pratiques (débroussaillages mécaniques notamment). En revanche, la structure démographique (quasi absence de juvéniles) laisse craindre un effondrement prochain de la population. Cette situation semble propre à cette population et non généralisable à l'ensemble des populations de la Provence

Le déclin alarmant des amphibiens de France : L'exemple étayé de la Normandie

International audienceThe alarming decline of amphibians in France: The documented example of Normandy. Amphibians are exposed to numerous pressures such as the disappearance and degradation of their terrestrial and aquatic habitats, the introduction of invasive species, diseases, and climate change, which lead to the disappearance or decline of populations. Many environmental assessments (e.g. European directives, red lists, etc.), or management practices in protected areas are based on the status of populations. In this context, a consortium (SHF, CPIE, ONF, RNF, CEFE) has developed protocols to assess trends in amphibian communities (or target species). Unlike the distribution atlas-type approaches already well developed in France, these new protocols (known as "POPAmphibien") are based on the site occupancy framework that model amphibian occurrence in aquatic sites, while correcting for the probability of species detection. This paper presents the results of the application of a POPAmphibien "community" protocol in Normandy, with the aim of describing the temporal trend of an amphibian community by carrying out three field surveys per year that considering the phenology of the different species. Between 2007 and 2018, 114 areas (sectors presenting several aquatic sites potentially colonised by amphibians) comprising 1255 aquatic sites were monitored using standardised methods. The trends for the 15 taxa monitored in Normandy show a decrease for nine of them (Alytes obstetricans, Bufo sp, Rana temporaria, Pelophylax kl. esculentus, Salamandra salamandra, Ichthyosaura alpestris, Triturus cristatus, Lissotriton helveticus and Lissotriton vulgaris), a stability for four species (Epidalea calamita, Pelophylax ridibundus, Hyla arborea and Triturus marmoratus) and an increase for two species (Rana dalmatina and Pelodytes punctatus). Habitat degradation, particularly in agricultural landscapes, and climate change (drying up of breeding sites) particularly affect species such as Salamandra salamandra and Rana temporaria. Management measures (over digging of ponds, protection of habitats) appear to be favourable to the populations of P. punctatus which are confined to dunes and coastal marshes under protection status. R. dalmatina is on the increase, particularly outside protected areas, probably due to its expansion northwards for at least fifteen yearsin connection with more favourable local climatic conditions and the presence of refuge micro-habitats. These are the first results obtained with this methodology, deployment on a national scale will enable increasing precise analyses of the factors influencing the dynamics of amphibian populations in France, including management practices.Le déclin alarmant des amphibiens de France : L’exemple étayé de la Normandie. Lesamphibiens subissent de nombreuses pressions comme la disparition et la dégradation de leurs habitatsterrestres et aquatiques, l’introduction d’espèces, les maladies et le changement climatique qui entrainentla disparition ou la régression des populations. De nombreuses évaluations environnementales (e.g.directives européennes, listes rouges, etc.), ou des pratiques de gestion dans des espaces protégéss’appuient sur la connaissance du statut des populations. Dans ce contexte, un consortium (SHF, CPIE,ONF, RNF et CEFE) a développé des protocoles permettant d’évaluer les tendances des communautés (oud’espèces) d’amphibiens. Contrairement aux approches de type atlas de répartition déjà bien développéesen France, ces nouveaux protocoles (dits « POPAmphibien ») s’inscrivent dans le cadre des méthodesd’occupation dynamique de sites qui permettent de modéliser les tendances de l’occurrence dans les sitesaquatiques, tout en corrigeant par la probabilité de détection des espèces. Cet article présente les résultatsde l’application d’un protocole POPAmphibien « communauté » en Normandie, avec l’objectif de décrire latendance temporelle d’une communauté d’amphibiens en réalisant trois passages par an sur le terrain quitiennent compte la phénologie des différentes espèces. Entre 2007 et 2018, 114 aires (secteurs présentantplusieurs sites aquatiques potentiellement colonisés par les amphibiens) comportant 1 255 sites aquatiquesont été suivis avec des méthodes de prospection standardisées. Les tendances des 15 taxons suivis enNormandie montrent une diminution pour neuf d’entre eux (Alyte accoucheur Alytes obstetricans, Crapaudcommun/épineux Bufo sp, Grenouille rousse Rana temporaria, Grenouille verte Pelophylax kl. esculentus,Salamandre tachetée Salamandra salamandra, Triton alpestre Ichthyosaura alpestris, Triton crêté Trituruscristatus, Triton palmé Lissotriton helveticus et Triton ponctué Lissotriton vulgaris), une stabilité pour quatreespèces (Crapaud calamite Epidalea calamita, Grenouille rieuse Pelophylax ridibundus, Rainette verte Hylaarborea et Triton marbré Triturus marmoratus) et une augmentation pour deux espèces (Grenouille agileRana dalmatina et Pélodyte ponctué Pelodytes punctatus). La dégradation des habitats, notamment dansles paysages agricoles et les changements climatiques (assèchement des sites de reproduction) affectentparticulièrement les espèces comme la Salamandre tachetée Salamandra salamandra et la Grenouillerousse Rana temporaria. Les mesures de gestion (surcreusement des mares, protection des habitats)apparaissent favorables aux populations de Pélodyte ponctué P. punctatus cantonnées dans les dunes et lesmarais littoraux, qui sont la plupart du temps sous statut de protection. La Grenouille agile (R. dalmatina) esten progression, notamment en dehors des espaces protégés, probablement en relation avec son expansionvers le nord depuis au moins une quinzaine d’années en lien avec des conditions climatiques locales plusfavorables et la présence de micro-habitats refuges. Ces résultats sont les premiers obtenus avec cetteméthodologie dont le déploiement à l’échelle nationale permettra des analyses de plus en plus précises surles facteurs, dont les pratiques de gestion, influençant la dynamique des populations des amphibiens deFrance

Transport infrastructure severely impacts amphibian dispersal regardless of life stage

International audienceTransport infrastructure such as roads has been reported to negatively affect dispersal. Their effects on dispersal are thought to be complex, depending on the characteristics of the structure and the intensity of the traffic using it. In addition, individual factors, such as age, may strongly affect dispersal decisions and success when individuals are confronted with transport infrastructure. Despite the importance of this topic for wildlife conservation, few studies have investigated the effect of transport infrastructure on individuals’ dispersal decisions before and after sexual maturity. We examined the effects on two kinds of infrastructure, gravel tracks and paved roads, on the dispersal of an endangered amphibian, the yellow-bellied toad (Bombina variegata). We used capture–recapture data collected during a five-year period on a large, spatially structured population of B. variegata. Our study revealed that emigration rates increased with an individual’s age, while dispersal distance decreased. It also showed that both tracks and roads had negative effects on immigration. The negative effect of roads was stronger than that of tracks. We additionally found that the effect of tracks on dispersal slightly decreased with a toad’s age. In contrast, the negative effect of roads was severe and relatively similar across age classes

Transport infrastructure severely impacts amphibian dispersal regardless of life stage

Transport infrastructure such as roads has been reported to negatively affect dispersal. Their effects on dispersal are thought to be complex, depending on the characteristics of the structure and the intensity of the traffic using it. In addition, individual factors, such as age, may strongly affect dispersal decisions and success when individuals are confronted with transport infrastructure. Despite the importance of this topic for wildlife conservation, few studies have investigated the effect of transport infrastructure on individuals’ dispersal decisions before and after sexual maturity. We examined the effects on two kinds of infrastructure, gravel tracks and paved roads, on the dispersal of an endangered amphibian, the yellow-bellied toad (Bombina variegata). We used capture–recapture data collected during a five-year period on a large, spatially structured population of B. variegata. Our study revealed that emigration rates increased with an individual’s age, while dispersal distance decreased. It also showed that both tracks and roads had negative effects on immigration. The negative effect of roads was stronger than that of tracks. We additionally found that the effect of tracks on dispersal slightly decreased with a toad’s age. In contrast, the negative effect of roads was severe and relatively similar across age classes

Déclin d’une population de Tortue d’Hermann (Testudo hermanni hermanni Gmelin, 1789) en milieu forestier. Effets combinés de plusieurs facteurs anthropiques

Decline of a Hermann’s Tortoise (Testudo hermanni hermanni Gmelin, 1789) population in forest. Combined effects of several anthropogenic factors. This study investigates the evolution of a population of Hermann’s tortoises, located on the edge of the massif des Maures, over a period of 30 years through capture– recapture monitoring. It shows a considerable decline of 73 % in the number of adult tortoises between the early 1980s and 1999 ; then from 1999, the population stabilized at around 100 adult tortoises. The fall in numbers during the first period seems to be linked to several factors. The 22 % increase in forest cover between 1983 and 1995 increased the concentrations of eggs laid in some open areas, making it easier for the species’ natural predators to find them. Mechanized clearance of undergrowth carried out in 1989 and 1994 has undoubtedly reduced the size of the population. The presence of dogs has posed an additional threat (97 % of the adult tortoises have bite marks and 7 % are missing limbs). In addition, the impact of dog bites on the tortoises’ shells has, over time, removed individual markings, thereby distorting survival estimates. The stabilization of numbers over the last decade seems to be due to the discontinuation of certain practices (notably mechanized undergrowth clearance). However, the demographic structure (with almost no juveniles) could soon lead to another decrease in population. This situation seems to be specific to this particular population and cannot be applied generally to all the populations in Provence.Cette étude analyse l’évolution d’une population de Tortue d’Hermann située en marge du massif des Maures sur une période de 30 années, sur la base de suivis par capture– recapture. Elle montre une baisse considérable des effectifs adultes (73 %) entre le début des années 1980 et 1999, puis une stabilisation de la population aux alentours de 100 individus adultes à partir de 1999. Cette chute des effectifs sur la première période semble liée à une addition de facteurs. L’augmentation de 22 % du couvert forestier entre 1983 et 1995 accroît la concentration des pontes sur quelques zones ouvertes, ce qui favorise leur découverte par les prédateurs naturels de l’espèce. Des débroussaillages mécaniques conduits en 1989 et 1994 ont certainement amoindri les effectifs de la population. La pression exercée par les chiens (actuellement 97 % des sujets adultes présentent des traces de crocs et 7 % des amputations de membres) vient ajouter une menace supplémentaire. De plus, les impacts de crocs de chien sur les carapaces de tortues ont provoqué une perte des marques individuelles au cours du temps, biaisant ainsi les estimations de survie. La stabilisation des effectifs depuis une dizaine d’années semble due à l’arrêt de certaines pratiques (débroussaillages mécaniques notamment). En revanche, la structure démographique (quasi absence de juvéniles) laisse craindre un effondrement prochain de la population. Cette situation semble propre à cette population et non généralisable à l’ensemble des populations de la Provence.Couturier Thibaut, Tillion-Lacazale Lucile, Besnard Aurélien, Astruc Guillelme, Cheylan Marc. Déclin d’une population de Tortue d’Hermann (Testudo hermanni hermanni Gmelin, 1789) en milieu forestier. Effets combinés de plusieurs facteurs anthropiques. In: Revue d'Écologie (La Terre et La Vie), tome 69, n°2, 2014. pp. 142-150

A habitat suitability analysis at multi-spatial scale of two sympatric flying fox species reveals the urgent need for conservation action

International audienceIn this study we used a multi-spatial scale approach to investigate habitat suitability, roosting characteristics, and ecological niche in two flying fox species on the Comoros Islands—Pteropus livingstonii and Pteropus seychellensis comorensis. At a broad scale, we assessed the ecological niche and habitat suitability for both species using the Species Distribution Modeling method based on the recent ensembles of small models (ESM) approach. At a fine scale, Ecological Niche Factor Analysis (ENFA) was applied to assess habitat selection by each species. Direct observation was used at each roost to estimate the total number of individuals and to identify the roost characteristics. At both broad and fine scales, the analyses highlighted clear niche partitioning by the two species. We found that P. livingstonii has a very limited distribution, restricted to steep, high-elevation slopes of the islands’ remaining natural forests, and the patterns were the same for roosting, foraging sites and the entire habitat. By contrast, P. s. comorensis has a relatively large geographic range that extends over low-elevation farmlands and villages and it was negatively correlated to natural forest across the entire area and all roosting sites, but its foraging areas were positively correlated to natural forest and high elevation areas. Both species selected large, tall trees for roosting. The total number of individuals in the studied area was estimated to be 1243 P. livingstonii and 11,898 P. s. comorensis. The results of our study demonstrated that these two species use different habitat types and ensure different ecosystem services in pollination and seed dispersion and thus are both critical for maintaining overall ecosystem dynamics. However, the currently high level of hunting pressure and roost disturbance makes them vulnerable to extinction. To ensure the viability of both species, conservation measures need to be taken by the Comoros government

Conservation of the endangered Mediterranean tortoise Testudo hermanni hermanni: The contribution of population genetics and historical demography

Estimating the genetic variation and demographic trends of species in decline is of major concern in conservation genetics. This study contributes to understanding how historical and anthropogenic factors shape the distribution of current genetic diversity in one of the most endangered reptiles in Western Europe, the Hermann's tortoise Testudo hermanni hermanni. We used 17 microsatellite loci, chosen from a pyrosequencing library specifically developed for the subspecies to genotype eight populations distributed over about 30 sample localities covering almost the entire geographic distribution of the sub-species. The population genetic results reflect a very strong genetic structure and identify three major clusters among the Hermann's tortoise in the occidental Mediterranean basin: a continental cluster (Albera in Spain, Var in France and continental Italy), an insular cluster (Corsica, Sardinia and Sicily) and a cluster of mixed lineage (Minorca). Each of the eight studied populations is characterized by only one lineage except for Minorca, in which two lineages were identified. In contrast to what most empirical studies predict, the genetic diversity of the Hermann's tortoise is greater on islands than on the continent. Islands can therefore be considered as genetic sanctuaries with high conservation potential for this species, particularly in Corsica. Historical demographic patterns inferred with a generalized stepwise-mutation model (GSM) using maximum likelihood showed significant past demographic changes in only two of the eight sampled populations: a demographic bottleneck was detected in the Albera population (Spain) and a demographic expansion in Corsica (France). In contrast to what was argued in previous studies, these results indicate that the Hermann's tortoise lineage found in Corsica is autochthonous. The origin of both lineages found in Minorca remains speculative. Lastly, our study identifies the six most relevant management units (sensu Moritz, 1994) for conservation purposes on the basis that they represent a significant part of the evolutionary legacy of the species. Some conservation recommendations were proposed, in particular for the most threatened population in Albera

Etat de l'art des connaissances sur les distributions spatiales des oiseaux marins et des petits poissons pélagiques dans le golfe du Lion

Cette étude présente les espèces et les peuplements de petits poissons pélagiques rencontrés au sein du golfe du Lion, ainsi que les espèces d’oiseaux marins qui y sont associées. Les données ont été collectées durant les campagnes à la mer PELMED (été) et JUVALION (hiver) de 1994 à 2010. Tout au long des différents chapitres, les analyses suivent un plan montrant successivement, pour les petits poissons pélagiques comme pour les oiseaux marins, les proportions relatives des différents groupes d’espèces composant chacun des peuplements étudiés puis, au sein de chacun de ces groupes, les distributions relatives de chacune des espèces observées. La cartographie et l’analyse des données présentées dans le présent rapport englobent d’une part toute la zone s’étendant de Cap Béar à Marseille (secteur camarguais compris), et replacent d’autre part les observations sur cette zone dans leurs contextes régionaux extérieurs. L’ensemble des cartes de distributions obtenues, établies à l’échelle de la totalité des campagnes annuelles, constituent les éléments écologiques indispensables à l’usage des scientifiques, gestionnaires et décideurs.

Building spaces of interactions between researchers and managers: Case studies with wildlife monitoring and conservation in France

International audience1. To document and halt biodiversity loss, monitoring, quantifying trends and assessing management and conservation strategies on wildlife populations and communities are crucial steps. 2. With increasing technological innovations, more and more data are collected and new quantitative methods are constantly developed. These rapid developments come with an increasing need for analytical skills, which are hardly accessible to managers. On the other hand, researchers spend more and more time on research grant applications and administrative tasks, which leaves fewer opportunities for knowledge transfer. This situation tends to increase the gap between researchers and managers. Here, we illustrate how to fill this gap by presenting two long-term collaborations between a research unit—Centre for Functional and Evolutionary Ecology; CEFE—and a national agency—French Biodiversity Agency; OFB. 3. The first example is a collaboration providing statistical support to national parks for the design and implementation of scientific monitoring protocols. It relies on the recruitment of a research engineer funded by OFB and physically based at CEFE, who works closely with OFB and managers. The second example is a collaboration on the management of large carnivores. For more than 10 years, it has involved several PhD students and post-doctoral fellows co-supervised by CEFE and OFB, and has recently resulted in the recruitment of a permanent OFB researcher who works half-time at CEFE and half-time at OFB. These case studies illustrate the modalities of collaborative work between public institutions acting at different levels of biodiversity conservation for the co-construction of research agendas and the exchange of knowledge. 4. These collaborations also bring out some challenges. Inter-knowledge and mutual learning remain difficult at scales larger than that of the teams concerned. The staff working at this interface needs to possess good listening skills, respect all partners' needs and demonstrate flexibility. Knowledge exchanges require time, thus reducing productivity according to quantitative metrics such as scientific publications or institutional reports. These collaborations can therefore be difficult to assume socially, and remain tenuous because they rely on a good understanding of the differences in governance of the various partners. 5. Based on our experience, success is favoured by long-term and close relationships, and by co-construction of projects at early stage. Sharing a space (i.e. office or building) facilitates face-to- face interactions during planned work sessions and casual meetings that build up a shared scientific culture and mutual trust