Association Vahatra

Antananarivo, Madagascar

Association Vahatra

Antananarivo, Madagascar
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PubMed | Madagasikara Voakajy, University of Antananarivo, Museo Regionale di Science Naturali, Ministere de lEnvironnement et des Forets and 17 more.
Type: Journal Article | Journal: PloS one | Year: 2014

An understanding of the conservation status of Madagascars endemic reptile species is needed to underpin conservation planning and priority setting in this global biodiversity hotspot, and to complement existing information on the islands mammals, birds and amphibians. We report here on the first systematic assessment of the extinction risk of endemic and native non-marine Malagasy snakes, lizards, turtles and tortoises.Species range maps from The IUCN Red List of Threatened Species were analysed to determine patterns in the distribution of threatened reptile species. These data, in addition to information on threats, were used to identify priority areas and actions for conservation. Thirty-nine percent of the data-sufficient Malagasy reptiles in our analyses are threatened with extinction. Areas in the north, west and south-east were identified as having more threatened species than expected and are therefore conservation priorities. Habitat degradation caused by wood harvesting and non-timber crops was the most pervasive threat. The direct removal of reptiles for international trade and human consumption threatened relatively few species, but were the primary threats for tortoises. Nine threatened reptile species are endemic to recently created protected areas.With a few alarming exceptions, the threatened endemic reptiles of Madagascar occur within the national network of protected areas, including some taxa that are only found in new protected areas. Threats to these species, however, operate inside and outside protected area boundaries. This analysis has identified priority sites for reptile conservation and completes the conservation assessment of terrestrial vertebrates in Madagascar which will facilitate conservation planning, monitoring and wise-decision making. In sharp contrast with the amphibians, there is significant reptile diversity and regional endemism in the southern and western regions of Madagascar and this study highlights the importance of these arid regions to conserving the islands biodiversity.


PubMed | University of Pretoria and Association Vahatra
Type: Journal Article | Journal: PloS one | Year: 2016

We provide serological evidence of lyssavirus circulation among bats on southwestern Indian Ocean (SWIO) islands. A total of 572 bats belonging to 22 species were collected on Anjouan, Mayotte, La Runion, Mauritius, Mah and Madagascar and screened by the Rapid Fluorescent Focus Inhibition Test for the presence of neutralising antibodies against the two main rabies related lyssaviruses circulating on the African continent: Duvenhage lyssavirus (DUVV) and Lagos bat lyssavirus (LBV), representing phylogroups I and II, respectively. A total of 97 and 42 sera were able to neutralise DUVV and LBV, respectively. No serum neutralised both DUVV and LBV but most DUVV-seropositive bats (n = 32/220) also neutralised European bat lyssavirus 1 (EBLV-1) but not Rabies lyssavirus (RABV), the prototypic lyssavirus of phylogroup I. These results highlight that lyssaviruses belonging to phylogroups I and II circulate in regional bat populations and that the putative phylogroup I lyssavirus is antigenically closer to DUVV and EBLV-1 than to RABV. Variation between bat species, roost sites and bioclimatic regions were observed. All brain samples tested by RT-PCR specific for lyssavirus RNA were negative.


Shi J.J.,Duke University | Shi J.J.,University of Michigan | Chan L.M.,Duke University | Chan L.M.,Pitzer and Scripps Colleges | And 4 more authors.
Biological Journal of the Linnean Society | Year: 2013

Numerous hypotheses have been proposed for the historical processes governing the rich endemism of Madagascar's biodiversity. The 'watershed model' suggests that drier climates in the recent geological past have resulted in the contraction of forests around major watersheds, thereby defining areas of endemism. We test whether this hypothesis explains phylogeographical patterns in a dry forest-dependent rodent, Eliurus myoxinus, an endemic species widely distributed through western Madagascar. We sequenced the mitochondrial cytochrome b locus and nuclear introns of the β-fibrinogen and the growth hormone receptor genes for E. myoxinus. Using a parametric bootstrapping approach, we tested whether the mitochondrial gene tree data fit expectations of local differentiation given the watershed model. We additionally estimated population differentiation and historical demographic parameters, and reconstructed the spatial history of E. myoxinus to highlight spatial and temporal patterns of differentiation. The data do not support the watershed model as a clear explanation for the genetic patterns of diversity within extant E. myoxinus populations. We find striking patterns of latitudinal genetic structure within western Madagascar, and indicate possible roles for environmental and ecological gradients along this axis in generating phylogeographical diversity. © 2013 The Linnean Society of London.


Dammhahn M.,University of Potsdam | Rakotondramanana C.F.,Association Vahatra | Rakotondramanana C.F.,University of Antananarivo | Goodman S.M.,Association Vahatra
Journal of Tropical Ecology | Year: 2015

Based on niche theory, closely related and morphologically similar species are not predicted to coexist due to overlap in resource and habitat use. Local assemblages of bats often contain cryptic taxa, which co-occur despite notable similarities in morphology and ecology. We measured in two different habitat types on Madagascar levels of stable carbon and nitrogen isotopes in hair (n = 103) and faeces (n = 57) of cryptic Vespertilionidae taxa to indirectly examine whether fine-grained trophic niche differentiation explains their coexistence. In the dry deciduous forest (Kirindy), six sympatric species ranged over 6.0‰ in δ15N, i.e. two trophic levels, and 4.2‰ in δ13C with a community mean of 11.3‰ in δ15N and-21.0‰ in δ13C. In the mesic forest (Antsahabe), three sympatric species ranged over one trophic level (δ15N: 2.4‰, δ13C: 1.0‰) with a community mean of 8.0‰ δ15N and-21.7‰ in δ13C. Multivariate analyses and residual permutation of Euclidian distances in δ13C-δ15N bi-plots revealed in both communities distinct stable isotope signatures and species separation for the hair samples among coexisting Vespertilionidae. Intraspecific variation in faecal and hair stable isotopes did not indicate that seasonal migration might relax competition and thereby facilitate the local co-occurrence of sympatric taxa. © 2014 Cambridge University Press.


Fuchs J.,University of California at Berkeley | Fuchs J.,University of Cape Town | Parra J.L.,University of Antioquia | Goodman S.M.,Field Museum of Natural History | And 4 more authors.
Biological Journal of the Linnean Society | Year: 2013

We conduct a phylogeographic study of the Crested Drongo (Dicrurus forficatus forficatus), a broadly distributed bird species on Madagascar. We first determined the demographic and spatial pattern inferred from mitochondrial and nuclear data, and then compared these results with predictions from a present to 0.120-Myr-old reconstruction of the spatial dynamics of the range of D.f.forficatus on Madagascar, enabling putative areas of stability (lineage persistence) to be detected. Weak genetic structure along an east-west pattern and comparatively low genetic diversity were recovered, with strong evidence of population expansion found at all ten loci sampled. The palaeoclimatic distribution models over the past 0.120Myr suggest the presence of extensive areas of suitable climate in the east and west for the species since its colonization of Madagascar, a result in strong concordance with the spatial and genetic signal derived from our multilocus data set. © 2013 The Linnean Society of London.


News Article | December 14, 2016
Site: www.csmonitor.com

A new study on a set of 3.66 million-year-old footprints has sparked a diverse series of conclusions about the owner of those feet. No more watching videos at work: Facebook will now default to audio Scientists work on preliminary digging and cleaning operations in December 2016 at the Laetoli site in northern Tanzania, where 14 footprints from a human ancestor, believed to be Australopithecus afarensis, were found. You remember “Lucy.” Meet her colleague. Or her mate? A set of footprints uncovered in 2015 by Tanzanian archeologists at the renowned northern Tanzanian site of Laetoli, and later analyzed with the help of a team of Italian scientists, has been found to belong to members of the same pre-human species as the fossil skeleton known as Lucy, or the Australopithecus afarensis species. The team’s results were published on Wednesday in the journal eLife. The 13 footprints, made on volcanic ash that later hardened into rock, were found among another 70 tracks discovered back in 1978 by paleontologist Mary Leakey, notes National Geographic, and together, the tracks are the oldest of their kind. Scientists have drawn a number of conclusions from the footprints, underscoring their usefulness in revealing biological characteristics. One of the two individuals responsible for the new tracks – called S1, after the first discovery made at the “S” site – is the tallest known member of Lucy's species at 5-foot, 5-inches and around 100 pounds. The team that authored the report says S1 would have stood out from his group, standing at least 8 inches taller than the individuals who made the other tracks and probably 3 inches taller than another large member of the species found earlier in Ethiopia. “The tall individual may have been the dominant male of a larger group, the others smaller females and juveniles,” wrote the researchers. “Thus, considerable differences may have existed between males and females in these remote human ancestors, similar to modern gorillas.” That could mean that similar to modern gorillas, A. afarensis could have had a social arrangement in which one dominant male lived with a group of females and their offspring, they say. “It’s not new in the sense of ‘A-ha!’ ” Briana Pobiner of the Smithsonian Institution’s Human Origins Program, who wasn’t involved with the study, told National Geographic. “But it is interesting that one of the individuals does seem to be a larger male than had been represented in the Laetoli sample.” Other scientists disagree: William Jungers, an anthropologist and research associate at the Association Vahatra in Madagascar who wrote a commentary on the study, told the Associated Press in an email that scientists had not recovered enough data to accurately estimate S1’s height. And Philip Reno, an assistant anthropology professor at Pennsylvania State University who was not involved in the study, said he was unconvinced that S1 was taller than the other large Ethiopian A. afarensis. The new report comes a few months after other scientists asserted that Lucy died after falling out of a tree, as The Christian Science Monitor’s Eva Botkin-Kowacki reported: The forensic evidence lies directly in Lucy's bones. A team led by Dr. Kappelman used CT scans to examine every bump and crack in her bones in an effort to reconstruct the individual hominin's life – and death.  The researchers compared breaks in Lucy's bones with the injuries sustained by humans today and found that "a number of fractures are consistent with the sorts of injuries seen in patients who have suffered a fall from a considerable height," Kappelman says.  Given that there were no skyscrapers to fall off, and Lucy's skeleton was unearthed far from any steep cliffs, Kappelman and his colleagues hypothesized that Lucy had been in a tree just before plummeting to her death. This report contains material from the Associated Press.


PubMed | University of Reunion Island, University of Pretoria, French Institute of Health and Medical Research, University of Leipzig and Association Vahatra
Type: Journal Article | Journal: FEMS microbiology ecology | Year: 2016

Pathogenic Leptospira are the causative agents of leptospirosis, a disease of global concern with major impact in tropical regions. Despite the importance of this zoonosis for human health, the evolutionary and ecological drivers shaping bacterial communities in host reservoirs remain poorly investigated. Here, we describe Leptospira communities hosted by Malagasy bats, composed of mostly endemic species, in order to characterize host-pathogen associations and investigate their evolutionary histories. We screened 947 individual bats (representing 31 species, 18 genera and seven families) for Leptospira infection and subsequently genotyped positive samples using three different bacterial loci. Molecular identification showed that these Leptospira are notably diverse and include several distinct lineages mostly belonging to Leptospira borgpetersenii and L. kirschneri. The exploration of the most probable host-pathogen evolutionary scenarios suggests that bacterial genetic diversity results from a combination of events related to the ecology and the evolutionary history of their hosts. Importantly, based on the data set presented herein, the notable host-specificity we have uncovered, together with a lack of geographical structuration of bacterial genetic diversity, indicates that the Leptospira community at a given site depends on the co-occurring bat species assemblage. The implications of such tight host-specificity on the epidemiology of leptospirosis are discussed.


Rakotoarisoa J.-E.,Illinois State University | Rakotoarisoa J.-E.,Yale University | Raheriarisena M.,University of Antananarivo | Goodman S.M.,Association Vahatra
Journal of Evolutionary Biology | Year: 2013

The Loky-Manambato region, located in northern Madagascar, is a biotically rich contact zone between different forest biomes. Local current forest cover is composed of both humid and dry formations, which show elevational stratification. A recent phylogeographical study of a regional dry forest rodent, Eliurus carletoni (subfamily Nesomyinae), found genetic evidence of forest contractions between 18 750 and 7500 years BP, which based on extrapolation of the pollen subfossil record, was thought to be associated with an expansion of local humid forests. Herein, we conduct a genetic test of this hypothesis and focused on populations on two neighbouring massifs of forest-dependent rodent species, one associated with low-elevation dry forests (E. carletoni) and the other with higher elevation humid forests (Eliurus tanala). Using mitochondrial markers and a combination of traditional and coalescent-based phylogeographical, historical demographic and population genetic methods, we found evidence of historical connections between populations of E. tanala. Adjacent populations of E. carletoni and E. tanala exhibit opposite historical demographic patterns, and for both, evidence suggests that historical demographic events occurred within the last 25 000 years BP. These findings strongly support the proposed late Quaternary shifts in the floristic composition of the Loky-Manambato region. © 2013 The Authors. © 2013 European Society For Evolutionary Biology.


PubMed | University of South Africa and Association Vahatra
Type: | Journal: BMC evolutionary biology | Year: 2015

The Commersons leaf-nosed bat, Hipposideros commersoni sensu stricto, is endemic to Madagascar and is relatively common in the western portion of the island, where it is found in areas, including forested zones, from sea level to 1325 m. A previous study on morphological patterns of geographic variation within the species highlighted the presence of two distinct morphotypes; larger individuals in the north portion of the island and smaller individuals in the south. The main aim of this study was to use a combination of craniodental morphology and molecular data (mitochondrial and nuclear) to test previous hypotheses based on morphology and clarify the evolutionary history of the species group.We sequenced mitochondrial and nuclear genes from Hipposideros commersoni obtained from the western portion of Madagascar, and compared them with other African species as outgroups. We analyzed the sequence data using Maximum Likelihood and Bayesian phylogenetic inference. Divergence dates were estimated using Bayesian molecular clock approach. Variation in craniodental variables was also assessed from sequenced individuals.The molecular analyses suggest that H. commersoni is not monophyletic, with strong support for the presence of several independently evolving lineages. Two individuals amongst those sequenced from Isalo (south central) and Itampolo (southwest) form a separate clade (Clade A), distinct from other H. commersoni, and sister to continental African H. vittatus and H. gigas. Within the H. commersoni clade, the molecular data support two geographically distributed clades; one from the south (Clade B) and the other from the north (Clade C), which diverged approximately 3.38 million years ago. Morphometric data were consistent with the molecular analyses, suggesting a north-south break within H. commersoni. However, at some localities, animals from both clades occurred in sympatry and these individuals could not be differentiated based on external and craniodental measurements.Using a combination of molecular and morphological characters, this study presents evidence of cryptic diversity in H. commersoni on Madagascar. Further fine-scale phylogeographic studies are needed to fully resolve the systematics of H. commersoni. This study highlights the utility of the combined approach in employing both morphological and molecular data to provide insights into the evolutionary history of Malagasy population currently assigned to H. commersoni.


News Article | December 14, 2016
Site: www.biosciencetechnology.com

He stood a majestic 5-foot-5, weighed around 100 pounds and maybe had a harem. That's what scientists figure from the footprints he left behind some 3.7 million year ago. He's evidently the tallest known member of the prehuman species best known for the fossil skeleton nicknamed "Lucy," reaching a stature no other member of our family tree matched for another 1.5 million years, the researchers say. The 13 footprints are impressions left in volcanic ash that later hardened into rock, excavated last year in northern Tanzania in Africa. Their comparatively large size, averaging a bit over 10 inches long (26 centimeters), suggest they were made by a male member of the species known as Australopithecus afarensis. The prints were found at a site called Laetoli, which is famous for another set of smaller footprints left by other A. afarensis individuals. Those made headlines in the 1970s as the earliest clear evidence of upright walking by our ancestors. The newly discovered prints are only about 160 yards (150 meters) away. Researchers named the new creature S1, for the first discovery made at the "S'' site. From the footprints, they calculated that he stood about 5-foot-5 (roughly 165 centimeters) and weighed around 100 pounds (about 45 kilograms). They figured that he loomed at least 8 inches (more than 20 centimeters) above the individuals who made the other tracks, and stood maybe 3 inches (7 centimeters) taller than a large A. afarensis specimen previously found in Ethiopia. "Lucy", also from Ethiopia, was much shorter at about 3 ½ feet (107 centimeters). The findings are described in a report released Wednesday by the journal eLife. Authors include Giorgio Manzi of Sapienza University in Rome, Marco Cherin of the University of Perugia in Italy, and others. Nobody knows the ages or sexes of any of the track-makers, although the size of the latest footprints suggest they were made by a male. It's quite possible that the new discovery means A. afarensis males were a lot bigger than females, with more of a difference than what is seen in modern humans, the researchers say. That's not a new idea, but it's still under debate. The large male-female disparity suggests A. afarensis may have had a gorilla-like social arrangement of one dominant male with a group of females and their offspring, the researchers said. But not everybody agrees with their analysis of S1's height. Their estimate is suspect, says anthropologist William Jungers, a research associate at the Association Vahatra in Madagascar who wrote a commentary on the study. That's because scientists haven't recovered enough of an A. afarensis foot to reliably calculate height from footprints, he said in an email. Philip Reno, an assistant anthropology professor at Penn State who didn't participate in the new work, said he believed the height estimate was in the right ballpark. But he's not convinced that S1 was really taller than the large Ethiopian A. afarensis. So rather than setting a record, "I think it confirms about the size we thought the big specimens were," Reno said. Manzi and Cherin said they can't be sure S1 was taller than the Ethiopian specimen. "We only suggest," they wrote in an email.

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