Differential distribution of Odonates and indigenous and exogenous salmonids in Orlu Protected Area (Ariège, France)

Species introduction may constitute an important threat to indigenous biodiversity. The naturalization of Brook Trout Salvelinus fontinalis in the Orlu Protected Area (Ariège, France) may affect local communities, especially Odonates. We surveyed the wetlands of this protected area in order to compare the distributions of Odonates and salmonids. Our results showed that the Brook Trout was absent in nearly all reproduction sites of Odonates. Brown Trout Salmo trutta fario was present in some of these sites. The sites where salmonids were present generally hosted few or no Odonates. Other sites were characterized by a relatively important typological and odonatological diversity, with specific assemblages that often showed an ecological and/or a heritage value. The spatial segregation was more conspicuous between Brook Trout and Odonates than between these latter and Brown Trout. Then, an eventual impact of Brook Trout on Odonates is plausible, but remains unconfirmed in our study in the absence of local data on the microhabitats occupied by both taxaL'introduction d'espèces peut constituer une menace importante pour la biodiversité indigène. La naturalisation du Saumon de fontaine Savelinus fontinalis dans la Réserve Nationale de Chasse et de Faune Sauvage d'Orlu (Ariège, France) est ainsi susceptible d'affecter les communautés locales et notamment les Odonates. Nous avons inventorié les Odonates et les Salmonidés dans les milieux humides de la réserve afin de comparer leurs distributions. Nos résultats montrent que le Saumon de fontaine est absent de presque tous les sites de reproduction d'Odonates. La Truite fario Salmo trutta fario est présente sur quelques uns de ces sites. Les sites de présence de Salmonidés accueillent généralement peu ou pas d'Odonates. Une diversité typologique et odonatologique assez importante caractérise les autres sites, avec des assemblages spécifiques, présentant souvent un intérêt écologique et/ou patrimonial. La ségrégation spatiale est apparue plus marquée entre le Saumon de fontaine et les Odonates qu'entre ces derniers et la Truite fario. Un éventuel impact du Saumon de fontaine sur les Odonates est donc plausible mais, en l'absence de données locales sur les microhabitats occupés par ces taxons, reste à confirmer

Migration flyway of the Mediterranean breeding Lesser Crested Tern Thalasseus bengalensis emigratus

© 2016 NISC (Pty) Ltd. The Lesser Crested Tern Thalasseus bengalensis emigratus breeding population in the Mediterranean is found exclusively in Libya, on the two coastal islands of Gara and Elba and one wetland on the mainland coast at Benghazi. In order to improve knowledge of the species migration to wintering quarters in West Africa, a ringing programme was conducted from 2006–2008 and 2009–2012. From a total of 1 354 nestlings ringed using metal and/or colour rings, 64 were recovered along their flyway and in their wintering range, representing 6.9% of birds ringed with both colour and metal rings. This provided the opportunity to collect information on post-natal movements (staging and wintering ranges), breeding philopatry and recruitment, in addition to a preliminary estimate of their migration journey duration. This paper indicates sighting and recovery distributions in space and time, highlighting the important areas for the species during its journey between breeding and wintering sites. The findings indicate that several areas where ringed terns stop-over during pre- and post-breeding migration journeys are not protected, causing an additional threat to their survival, as some wintering areas are also not protected. Conservation of this highly localised and threatened population needs not only to address protection at breeding sites but also at migratory stop-overs and wintering strongholds

Is the Red-crested Pochard Netta rufina really Endangered in France ?

Defos du Rau Pierre. Is the Red-crested Pochard Netta rufina really Endangered in France ?. In: Ecologia mediterranea, tome 29 n°2, 2003. pp. 252-253

Distribution différentielle des Odonates et des Salmonidés indigènes et exogènes dans la réserve d’Orlu (Ariège, France)

Differential distribution of Odonates and indigenous and exogenous salmonids in Orlu Protected Area (Ariège, France). — Species introduction may constitute an important threat to indigenous biodiversity. The naturalization of Brook Trout Salvelinus fontinalis in the Orlu Protected Area (Ariège, France) may affect local communities, especially Odonates. We surveyed the wetlands of this protected area in order to compare the distributions of Odonates and salmonids. Our results showed that the Brook Trout was absent in nearly all reproduction sites of Odonates. Brown Trout Salmo trutta fario was present in some of these sites. The sites where salmonids were present generally hosted few or no Odonates. Other sites were characterized by a relatively important typological and odonatological diversity, with specific assemblages that often showed an ecological and/or a heritage value. The spatial segregation was more conspicuous between Brook Trout and Odonates than between these latter and Brown Trout. Then, an eventual impact of Brook Trout on Odonates is plausible, but remains unconfirmed in our study in the absence of local data on the microhabitats occupied by both taxa.L’introduction d’espèces peut constituer une menace importante pour la biodiversité indigène. La naturalisation du Saumon de fontaine Savelinus fontinalis dans la Réserve Nationale de Chasse et de Faune Sauvage d’Orlu (Ariège, France) est ainsi susceptible d’affecter les communautés locales et notamment les Odonates. Nous avons inventorié les Odonates et les Salmonidés dans les milieux humides de la réserve afin de comparer leurs distributions. Nos résultats montrent que le Saumon de fontaine est absent de presque tous les sites de reproduction d’Odonates. La Truite fario Salmo trutta fario est présente sur quelques uns de ces sites. Les sites de présence de Salmonidés accueillent généralement peu ou pas d’Odonates. Une diversité typologique et odonatologique assez importante caractérise les autres sites, avec des assemblages spécifiques, présentant souvent un intérêt écologique et/ou patrimonial. La ségrégation spatiale est apparue plus marquée entre le Saumon de fontaine et les Odonates qu’entre ces derniers et la Truite fario. Un éventuel impact du Saumon de fontaine sur les Odonates est donc plausible mais, en l’absence de données locales sur les microhabitats occupés par ces taxons, reste à confirmer.Bonifait Sylvain, Defos du Rau Pierre. Distribution différentielle des Odonates et des Salmonidés indigènes et exogènes dans la réserve d’Orlu (Ariège, France). In: Revue d'Écologie (La Terre et La Vie), tome 62, n°4, 2007. pp. 285-294

Intensive agriculture as the main limiting factor of the otter's return in southwest France

International audienceRewilding has become a new paradigm to promote the natural recovery of many flagship species, including large carnivores. A better understanding of the factors that drive rewilding processes would allow predicting these in order to support them where desirable. Yet large-scale assessments of the factors that favor or limit mammal populations of conservation concern remain rare in Europe. This study sought to monitor changes in Eurasian otter (Lutra lutra) occupation over the years to identify the factors limiting its recolonization. To this end, we monitored otter signs and spraints over 1238 sampling sites in southwest France from 2003 to 2005 and then over 615 sites in 2011-2012. We modeled this dataset in a multi-season occupancy framework using biotic and abiotic covariates identified as potentially affecting otter detection, distribution and/or colonization rates. As otters are a cryptic and mobile mammal, we integrated detection probability and spatial autocorrelation (contagion) into the modeling design. Otter occurrence was detected at 31 % of the sites surveyed in 2003-2005 and 37 % of the sites surveyed in 2011-2012. Occupancy and colonization probabilities were strongly negatively correlated to the proportion of cultivated areas. Contagion covariates interacted strongly with other variables. These results suggest that, despite its recent colonization, the otter population in southwest France is still constrained in its expansion, notably by intensive agriculture. Natura 2000 schemes should incorporate rewilding approaches to further potentiate the colonization of this flagship species. Actions should focus on the conservation of natural riparian habitats and promote organic agriculture

Intensive agriculture as the main limiting factor of the otter's return in southwest France

International audienceRewilding has become a new paradigm to promote the natural recovery of many flagship species, including large carnivores. A better understanding of the factors that drive rewilding processes would allow predicting these in order to support them where desirable. Yet large-scale assessments of the factors that favor or limit mammal populations of conservation concern remain rare in Europe. This study sought to monitor changes in Eurasian otter (Lutra lutra) occupation over the years to identify the factors limiting its recolonization. To this end, we monitored otter signs and spraints over 1238 sampling sites in southwest France from 2003 to 2005 and then over 615 sites in 2011-2012. We modeled this dataset in a multi-season occupancy framework using biotic and abiotic covariates identified as potentially affecting otter detection, distribution and/or colonization rates. As otters are a cryptic and mobile mammal, we integrated detection probability and spatial autocorrelation (contagion) into the modeling design. Otter occurrence was detected at 31 % of the sites surveyed in 2003-2005 and 37 % of the sites surveyed in 2011-2012. Occupancy and colonization probabilities were strongly negatively correlated to the proportion of cultivated areas. Contagion covariates interacted strongly with other variables. These results suggest that, despite its recent colonization, the otter population in southwest France is still constrained in its expansion, notably by intensive agriculture. Natura 2000 schemes should incorporate rewilding approaches to further potentiate the colonization of this flagship species. Actions should focus on the conservation of natural riparian habitats and promote organic agriculture

Planning from scratch: A new modelling approach for designing protected areas in remote, data‐poor regions

International audienceAbstract Human pressure on ecosystems has strongly increased over the last decades and now impacts even the most remote regions. To help mitigate these impacts, it is crucial to designate protected areas in regions that retain a high level of ecological integrity. However, ecological data remain scarce for many such areas, making the systematic design of new protected zones challenging. Following a request from local managers, we developed an original methodological approach to help design new zoning for a pre‐existing protected area in a remote, data‐poor Sahelian wetland of southern Chad, a vast area rich in biodiversity and exploited by diverse human activities. The method involved first collecting extensive aerial survey data (6252 records) on birds and mammals and then analysing this through a combination of distance sampling and density surface modelling. The biodiversity data, combined with ecological predictors, helped model species distribution layers that were then incorporated with socio‐economic constraints into the systematic conservation planning tool Marxan. This approach produced an array of protected zoning options that met three levels of conservation objectives set by experts, corresponding to proportions of individuals from given species to protect in the proposed protected area. Frequent exchanges with local managers allowed the analyses to be refined, resulting in seven potential scenarios to be considered for conservation purposes. Synthesis and applications . In a context of high data scarcity, lack of access and short‐term conservation objectives, this combined approach that optimizes newly obtained data via a suite of modelling tools can facilitate identifying and protecting natural areas in regions most in need of urgent conservation policy.Résumé La pression humaine sur les écosystèmes s'est fortement accrue au cours des dernières décennies et touche désormais même les régions les plus reculées. Pour atténuer ces effets, il est essentiel de désigner des zones protégées dans les régions qui conservent un niveau élevé d'intégrité écologique. Cependant, les données écologiques restent rares pour beaucoup de ces zones, ce qui rend difficile la conception de nouvelles zones protégées. À la demande de gestionnaires locaux, nous avons développé une approche méthodologique originale pour aider à concevoir un nouveau zonage pour une zone protégée préexistante autour d’une zone humide sahélienne isolée et pauvre en données du sud du Tchad, une vaste région d’une remarquable biodiversité et exploitée par diverses activités humaines. La méthode consistait d'abord à collecter par avion des données détaillées sur les oiseaux et les mammifères (n=6252), puis à les analyser en combinant les méthodes dites de « distance sampling » et de « density surface modelling ». Les données de biodiversité, combinées à des prédicteurs écologiques, ont permis de modéliser des couches de distribution des espèces qui ont ensuite été incorporées avec des contraintes socio‐économiques dans l'outil de planification systématique de la conservation Marxan. Cette approche a permis de produire un ensemble d'options de zonage répondant à trois niveaux d'objectifs de conservation déterminés par les effectifs d'espèces à intégrer dans la zone protégée proposée. Des échanges fréquents avec les gestionnaires locaux ont permis d'identifier sept scénarios potentiels à considérer à des fins de conservation. Synthèse et applications. Dans un contexte de forte pénurie de données, d'accès fortement limité à la zone d’étude et d'objectifs de conservation à court terme, cette approche combinée optimise les données nouvellement obtenues par avion via une suite d'outils de modélisation et peut faciliter l'identification et la protection des zones à forte valeur patrimoniale dans les régions qui ont le plus besoin d'une politique de conservation urgente

Reassessment of the size of the Scopoli's Shearwater population at its main breeding site resulted in a tenfold increase: implications for the species conservation

International audienceScopoli's Shearwater (Calonectris diomedea) is a Procellariiform endemic to the Mediterranean Basin which is considered to be vulnerable in Europe due to recent local declines and its susceptibility to both marine and terrestrial threats. In the 1970s-1980s, its population size was estimated at 57,000-76,000 breeding pairs throughout the Mediterranean Basin, with the largest colony, estimated at 15,000-25,000 pairs, found on Zembra Island, Tunisia. The objectives of our study were to re-estimate the size of the breeding population on Zembra Island, to reassess the global population size of the species, and to analyse the implications of these findings on status and conservation of this species in the Mediterranean. Using distance sampling, we estimated the Zembra breeding population to be 141,780 pairs (95 % confidence interval 113,720-176,750 pairs). A review of the most recent data on populations of this species throughout the Mediterranean Basin led us to estimate its new global population size at 141,000-223,000 breeding pairs. Using the demographic invariant and potential biological removal approaches, we estimated the maximum number of adults which could be killed annually by all non-natural causes without causing a population decline to be 8800 (range 7700-9700) individuals, of which could be 3700 breeders. Although these results are less alarming in the context of species conservation than previously thought, uncertainties associated with global population size, trends and major threats still raise questions on the future of this species. More generally, we show how a monitoring strategy for a bird supposed to be relatively well known overall can be potentially misleading due to biases in survey design. The reduction of such biases would therefore appear to be an unavoidable prerequisite in cryptic species monitoring before any reliable inference on the conservation status of the species can be drawn