Phylogeography and demographic history of the neotropical otter (Lontra longicaudis)

The Neotropical otter (Lontra longicaudis) is a medium-sized semiaquatic carnivore with a broad distribution in the Neotropical region. Despite being apparently common in many areas, it is one of the least known otters, and genetic studies on this species are scarce. Here, we have investigated its genetic diversity, population structure, and demographic history across a large portion of its geographic range by analyzing 1471 base pairs (bp) of mitochondrial DNA from 52 individuals. Our results indicate that L. longicaudis presents high levels of genetic diversity and a consistent phylogeographic pattern, suggesting the existence of at least 4 distinct evolutionary lineages in South America. The observed phylogeographic partitions are partially congruent with the subspecies classification previously proposed for this species. Coalescence-based analyses indicate that Neotropical otter mitochondrial DNA lineages have shared a rather recent common ancestor, approximately 0.5 Ma, and have subsequently diversified into the observed phylogroups. A consistent scenario of recent population expansion was identified in Eastern South America based on several complementary analyses of historical demography. The results obtained here provide novel insights on the evolutionary history of this largely unknown Neotropical mustelid and should be useful to design conservation and management policies on behalf of this species and its habitats. © The American Genetic Association. 2012. All rights reserved

Olive ridley turtle Lepidochelys olivacea in French Guiana: back from the brink of regional extirpation?

Short CommunicationsInternational audienceThe estimated number of olive ridley marine turtles Lepidochelys olivacea nesting annually in 2002–2007 in French Guiana was 1,716–3,257, the highest ever recorded in the country and similar to nesting numbers recorded in neighbouring Suriname c. 40 years ago, where the species has now severely declined. A shift of nesting females from Suriname to French Guiana beaches and improvement of nationwide marine turtle monitoring appear to be the most plausible explanations for the current high level of nesting recorded in French Guiana. The species' nesting status in French Guiana therefore appears less critical than previously documented but ongoing threats suggest the need to reinforce regional conservation efforts in the West Atlantic

Dispersal and dive patterns during the post-nesting migration of olive ridley turtles from French Guiana

International audienceBehavioral plasticity allows migrating animals to adjust their migration patterns inrelation to the environmental conditions they encounter during their movements. Sea turtles displaylong post-nesting migrations which vary considerably between species and populations. Todate, there has been no description of migratory patterns of the large population of olive ridley turtlesLepidochelys olivacea in the west Atlantic. Here, we investigated dispersal and dive patternsin relation to environmental conditions of 7 satellite-tracked olive ridley females from FrenchGuiana during their post-nesting migration. After they left the nesting beach, turtles followed aconsistent northwestward direction and then remained in the restricted yet productive neriticdomain of the continental shelf of French Guiana and Suriname. Despite this restricted dispersalrange, turtles demonstrated variability in the habitats they exploited, i.e. the coastline, the continentalshelf, and the continental slope, illustrating some plasticity. Moreover, turtles showed 2 differentforaging strategies, either directly reaching a specific foraging area off river mouths, ormeandering over the neritic area exploiting several foraging areas. In addition, turtles showed differentdive patterns related to their habitat, although mostly exploiting the seabed by routinelyperforming U-shaped benthic dives. Overall, turtles vertically exploited non-stratified watermasses characterized by warm surface temperatures consistent with their preferential thermalhabitat. The migration strategy used by olive ridleys from French Guiana raises conservation concerns,since turtles may be exposed to coastal human-induced activities that must be consideredin the implementation of accurate management measures for this still poorly studied populatio

Bilan des espèces exotiques envahissantes en milieux aquatiques sur le territoire français : bilan synthétique pour l'outre-mer

Les nombreuses espèces exotiques envahissantes présentes dans les territoires français d’outre-mer représentent une menace potentielle ou déjà manifeste pour les écosystèmes et les espèces particulièrement vulnérables qu'ils abritent. Cet article présente un état des lieux de la situation et quelques chiffres clés

Forests and emerging infectious diseases: unleashing the beast within

International audienceDeforestation and associated changing landscapes are major components of environmental changes, with important implications for ecosystem functioning and biodiversity conservation. Tropical forests are hot spots of biodiversity and provide multiple goods and ecosystem services which benefit people in many ways. Forests also play an important role in health-related legends, myths, and fairy tales from all over the world, and are important sources of new potential emerging microbial threats to humans. Although plausibly numerous abundant microbial forms with a forest origin may exist, our systematic literature review shows that forest-derived infection studies are relatively unexplored, and both taxonomically and geographically biased. Since biodiversity has been associated with emergence of novel infectious diseases at macro-scale, we describe the main biogeographical patterns in the emerging infection-biodiversity-forest loss nexus. Then, we illustrate four fine-scale case studies to decipher the underlying processes of increased infection risk in changing forest clearing landscapes. Finally, we identify scientific challenges and regional management measures required to mitigate these important new emerging threats

Paramyxovirus circulation in bat species from French Guiana

International audienceBats are recognized as reservoirs of numerous viruses. Among them, paramyxoviruses, for example, Hendra and Nipah viruses, are highly pathogenic to humans. Nothing is known regarding the circulation of this viral family in bats from French Guiana. To search for the presence of paramyxoviruses in this territory, 103 bats of seven different species were sampled and screened using a molecular approach. Four distinct paramyxovirus sequences were detected from three bat species (Desmodus rotundus, Carollia perspicillata, and Pteronotus alitonus) at high prevalence rates. In D. rotundus, two types of paramyxovirus cocirculate, with most of the bats co-infected. The phylogenetic analysis of these sequences revealed that three of them were closely related to previously characterized sequences from D. rotundus, C. perspicillata, and P. parnellii from Brazil and Costa Rica. The fourth sequence, identified in D. rotundus, was closely related to the one detected in P. alitonus in French Guiana and to previously described sequences detected in P. parnellii in Costa Rica. All paramyxovirus sequences detected in this study are close to the Jeilongvirus genus. Altogether, our results and those of previous studies indicate a wide geographical distribution of these paramyxoviruses (from Central to South America) and suggest potential cross-species transmissions of paramyxoviruses between two different bat families: Mormoopidae (P. alitonus) and Phyllostomidae (D. rotundus). In addition, their closeness to paramyxoviruses identified in rodents emphasizes the need to investigate the role of these animals as potential reservoirs or incidental hosts. Finally, the high prevalence rates of some paramyxoviruses in certain bat species, associated with the presence of large bat colonies and, in some cases, their potential proximity with humans are all parameters that can contribute to the risk of cross-species transmission between bat species and to the emergence of new paramyxoviruses in humans, a risk that deserves further investigation