Diet pattern and variations of Ocellated Lizard Timon lepidus in a Mediterranean steppe area (Crau plain, France)

The diet of Ocellated Lizard, a reptile considered as vulnerable in Europe, was studied in a protected area containing one of the most important French populations of the species. It aims to describe diet composition and its temporal variation but also to identify differences between age classes. A sample of 221 scats was collected from May to September 2010 in seven different sites of the studied area (Crau plain, France). From the 4029 items analysed, 156 taxa were identified. The diet is composed by Coleoptera (26.7 %), Orthoptera (23 %), Hymenoptera (19.3 %) and fruits (17.1 %). Dung beetles represent only 2.1 % of Coleoptera prey, which is surprising for such a heavily grazed area. The diet composition is different from one month to another (χ2 = 943.173, df = 20, p < 0.001) and differences between age classes exist (V = 572, p < 0.001). Adult lizards eat more fruits than juveniles in August (χ2 = 80.349, df = 1, p < 0.001). The prey richness is not different between adults and juveniles (Z = 1.839, p > 0.05). Finally, diet characteristics in the Crau plain are discussed and compared to other Iberian and French Ocellated Lizard populationsNous avons étudié le régime alimentaire du Lézard ocellé, espèce considérée comme vulnérable en Europe, sur un espace naturel protégé abritant une des plus importantes populations françaises. Nous proposons de décrire la composition et les variations saisonnières du régime alimentaire dans la Réserve naturelle de Crau, et d'identifier les différences entre les classes d'âge. Un échantillon de 221 fèces a été récolté entre mai et septembre 2010 sur sept localités de la zone d'étude. Les 4029 proies et restes végétaux analysés ont permis d'identifier 156 taxons différents. Le régime se compose de Coléoptères (26,7 %), d'Orthoptères (23 %), d'Hyménoptères (19,3 %) et de fruits (17,1 %). Les Coléoptères coprophages ne représentent que 2,1 % de tous les Coléoptères consommés, ce qui est surprenant pour un site aussi fortement pâturé. Il existe une variation saisonnière de la composition (χ² = 943,173, df = 20, p < 0,001) mais aussi selon la classe d'âge (V = 572, p < 0,001). Les adultes consomment beaucoup plus de fruits au mois d'août que les juvéniles (χ² = 80,349, df = 1, p 0,05). Les particularités de la Crau sont discutées et comparées aux autres études existantes dans la péninsule ibérique et en France

Discovery of an Italian slow worm (Anguis veronensis Pollini, 1818) population on a Western Mediterranean Island confirmed by genetic analysis

The genus Anguis is known to be mainly continental in the Mediterranean area, and accordingly it has never been recorded in Western Mediterranean islands. Here we report for the first time the presence of the slow worm in a Western Mediterranean island, the Ile Sainte-Marguerite from Lérins archipelago (southeastern France). The molecular analysis of ND2 and PRLR genes assigned the specimens to A. veronensis Pollini, 1818 and showed that they are genetically related to the mainland population from Les Mayons, in mainland France.

Monitoring amphibian species with complex chromatophore patterns: a non- invasive approach with an evaluation of software effectiveness and reliability

International audienceThe estimation of demographic parameters in wild populations is strengthened by individual identification. For amphibians, various techniques are used to either temporarily or permanently mark individuals for identification. Photo-identification of body patterns offers a non-invasive technique. However, the reliability of photo-recognition software is key to the reliable estimation of the true demographic parameters. In the current study, we assessed the effectiveness of fully-automated and semi-automated software: Wild-ID and APHIS. We used the cryptic salamander Hydromantes strinatii as our study species. We used the False Rejection Rate (FRR) of Top 1, Top 5 and Top 10 matches of chest and cloaca pictures. Finally, we assessed the bias induced by our FRR for the estimation of population size through simulation. Wild-ID FRRs ranged from 0.042 to 0.093 while APHIS' ranged from 0.227 to 0.547. Wild-ID was equally efficient with pictures from the chest and from the cloaca, while APHIS was significantly more efficient with chest pictures than cloaca pictures. Cropping pictures did not significantly improve Wild-ID effectiveness. Our Wild-ID FRRs are among the lowest ever obtained from pictures of an amphibian with a complex chromatophore pattern. Simulation showed that the Top 10 FRR from selected software Wild-ID induced a low bias 2.7% on the estimation of population size. The effectiveness and plasticity of Wild-ID provides opportunities for reliably monitoring amphibian species with complex colour pattern

Patron et variations du régime alimentaire du Lézard ocellé Timon lepidus en milieu steppique méditerranéen semi-aride (plaine de Crau, France)

Diet pattern and variations of Ocellated Lizard Timon lepidus in a Mediterranean steppe area (Crau plain, France). The diet of Ocellated Lizard, a reptile considered as vulnerable in Europe, was studied in a protected area containing one of the most important French populations of the species. It aims to describe diet composition and its temporal variation but also to identify differences between age classes. A sample of 221 scats was collected from May to September 2010 in seven different sites of the studied area (Crau plain, France). From the 4029 items analysed, 156 taxa were identified. The diet is composed by Coleoptera (26.7 %), Orthoptera (23 %), Hymenoptera (19.3 %) and fruits (17.1 %). Dung beetles represent only 2.1 % of Coleoptera prey, which is surprising for such a heavily grazed area. The diet composition is different from one month to another (χ2 = 943.173, df = 20, p < 0.001) and differences between age classes exist (V = 572, p 0.05). Finally, diet characteristics in the Crau plain are discussed and compared to other Iberian and French Ocellated Lizard populations.Nous avons étudié le régime alimentaire du Lézard ocellé, espèce considérée comme vulnérable en Europe, sur un espace naturel protégé abritant une des plus importantes populations françaises. Nous proposons de décrire la composition et les variations saisonnières du régime alimentaire dans la Réserve naturelle de Crau, et d’identifier les différences entre les classes d’âge. Un échantillon de 221 fèces a été récolté entre mai et septembre 2010 sur sept localités de la zone d’étude. Les 4029 proies et restes végétaux analysés ont permis d’identifier 156 taxons différents. Le régime se compose de Coléoptères (26,7 %), d’Orthoptères (23 %), d’Hyménoptères (19,3 %) et de fruits (17,1 %). Les Coléoptères coprophages ne représentent que 2,1 % de tous les Coléoptères consommés, ce qui est surprenant pour un site aussi fortement pâturé. Il existe une variation saisonnière de la composition (χ² = 943,173, df = 20, p 0,05). Les particularités de la Crau sont discutées et comparées aux autres études existantes dans la péninsule ibérique et en France.Tatin Laurent, Chapelin-Viscardi Jean-David, Renet Julien, Becker Etienne, Ponel Philippe. Patron et variations du régime alimentaire du Lézard ocellé Timon lepidus en milieu steppique méditerranéen semi-aride (plaine de Crau, France). In: Revue d'Écologie (La Terre et La Vie), tome 68, n°1, 2013. pp. 47-58

L’étude du régime alimentaire du Lézard ocellé dans la Plaine de Crau: apports écologiques et entomologiques

International audienc

Spatial pattern and shelter distribution of the ocellated lizard (Timon lepidus) in two distinct Mediterranean habitats

International audienceThe knowledge of a species' spatial ecology is essential for its conservation as it helps to implement targeted protection measures to suitable habitats. In 2011 and 2013, two French populations of ocellated lizards Timon lepidus were monitored through very high frequency (VHF) radio telemetry in two distinct Mediterranean habitats: a 77 ha scrubland (n = 8) and a 1590 ha semi-arid steppe (n = 11) corresponding to a heterogeneous and homogeneous habitat respectively. The variability in spatial estimates for the seasonal habitat use of the ocellated lizard was compared within the two sites using the Autocorrelated Kernel Density Estimation (AKDE). Recursive movement patterns and spatial repartition of shelters were further assessed to study the habitat influence on the species' space use. No significant differences between sexes or sites were identified in the computed AKDE ranges. This inter-site approach demonstrated higher shelter revisits in core-areas than in the rest of estimated home ranges for both sites. A higher shelter density was observed in the core areas of the lizards than in the rest of their home-ranges for the Mediterranean scrubland but not for the semi-arid steppe. Such findings might attest to the species' adaptive capabilities within two distinct Mediterranean ecosystems

L’étude du régime alimentaire du Lézard ocellé dans la Plaine de Crau: apports écologiques et entomologiques

International audienc

Colonization routes uncovered in a widely introduced Mediterranean gecko, Tarentola mauritanica

Abstract In this study, we aimed to understand the contemporary and ancient colonization routes of the Moorish gecko, Tarentola mauritanica, using simple sequence repeats. By analyzing the genetic diversity of populations in different regions, we found that Morocco is the genetic diversity hotspot for the species, followed by the Iberian Peninsula. However, historical gene flow estimates identified the Iberian Peninsula, not Morocco, as the primary contributor of colonizing individuals, along with continental Italy to a lesser extent. Currently, mainland Italy is the main source of introduced individuals, likely due to the plant nursery trade. The study suggests that human-facilitated introductions from various geographical origins, with numerous regions colonized through continental Italy during two distinct periods, are responsible for the recurrent entry of individuals belonging to the European lineage of T. mauritanica into the Mediterranean and Macaronesia. These findings can inform better monitoring surveys and conservation programs by identifying putative current colonization routes of alien species

Altered bioavailability of epoxyeicosatrienoic acids is associated with conduit artery endothelial dysfunction in type 2 diabetic patients

International audienceBackground: This pathophysiological study addressed the hypothesis that soluble epoxide hydrolase (sEH), which metabolizes the vasodilator and anti-inflammatory epoxyeicosatrienoic acids (EETs) to dihydroxyeicosatrienoic acids (DHETs), contributes to conduit artery endothelial dysfunction in type 2 diabetes. Methods and results: Radial artery endothelium-dependent flow-mediated dilatation in response to hand skin heating was reduced in essential hypertensive patients (n = 9) and type 2 diabetic subjects with (n = 19) or without hypertension (n = 10) compared to healthy subjects (n = 36), taking into consideration cardiovascular risk factors, flow stimulus and endothelium-independent dilatation to glyceryl trinitrate. Diabetic patients but not non-diabetic hyper-tensive subjects displayed elevated whole blood reactive oxygen species levels and loss of NO release during heating, assessed by measuring local plasma nitrite variation. Moreover, plasma levels of EET regioisomers increased during heating in healthy subjects, did not change in hypertensive patients and decreased in diabetic patients. Correlation analysis showed in the overall population that the less NO and EETs bioavailability increases during heating, the more flow-mediated dilatation is reduced. The expression and activity of sEH, measured in isolated peripheral blood mono-nuclear cells, was elevated in diabetic but not hypertensive patients, leading to increased EETs conversion to DHETs. Finally, hyperglycemic and hyperinsulinemic euglycemic clamps induced a decrease in flow-mediated dilatation in healthy subjects and this was associated with an altered EETs release during heating. Conclusions: These results demonstrate that an increased EETs degradation by sEH and altered NO bioavailability are associated with conduit artery endothelial dysfunction in type 2 diabetic patients independently from their hyperten-sive status. The hyperinsulinemic and hyperglycemic state in these patients may contribute to these alterations