18 research outputs found

    Inventaire biologique de la forêt littorale de Tampolo (Fenoarivo Atsinanana)

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    Phylogenetic relationships of Malayan and Malagasy pygmy shrews of the genus suncus (soricomorpha: soricidae) inferred from mitochondrial cytochrome B gene sequences

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    This study used a portion of the mitochondrial cytochrome b gene to investigate the phylogenetic relationships of Suncus pygmy shrews and to help clarify the taxonomic status of the Malayan pygmy shrew (S. malayanus) and the Malagasy pygmy shrew (S. madagascariensis). Phylogenetic reconstructions were performed using neighbour-joining and Bayesian analysis methods and revealed that S. malayanus is related to, but distinct from S. etruscus. The K2P-corrected genetic distance among the Malaysian taxon and other pygmy shrews for the cytochrome b gene was between 6.1 and 8.5%, supporting recognition that S. malayanus represents a distinct species from the geographically widespread S. etruscus species complex. A close (1.5% K2P distance) sister-group relationship was revealed between S. etruscus from Sri Lanka and S. madagascariensis from Madagascar, which has been considered an island endemic, and suggests that these animals are not specifically distinct. The Malagasy population of this shrew most probably was translocated to the island by human intervention, with the lineage originating from Southeast Asia or the Indian subcontinent

    Comparative assessment on rodent impacts and cultural perceptions of ecologically based rodent management in 3 Afro-Malagasy farming regions

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    Rodents generate negative consequences for smallholder farmers in Africa that directly impact household and livestock damage, food security, and public health. Ecologically Based Rodent Management (EBRM) seeks sustainable solutions for the mitigation of rodent damage through assessments of rodent population dynamics, agro-ecosystems, and socio-cultural contexts. We adopt a comparative approach across 3 rural Afro-Malagasy smallholder farming regions in South Africa, Tanzania, and Madagascar to assess the household impacts of rodent pests and current perceptions and preferences associated with several rodent control measures. We conducted focus group questionnaires and interviews in different study site locations. Rodents assert multiple impacts on Afro-Malagasy farmers demonstrating recurrent and emerging agricultural and household costs, and public health impacts. We identify a significant knowledge gap in educating communities about the application of different EBRM approaches in favor of acute poisons that are perceived to be more effective. Cultural issues and taboos also have a significant impact on the social acceptance of rodent hunting as well as biological control using indigenous predators. We advocate for an enhanced investigation of the socio-cultural beliefs associated with different rodent practices to understand the factors underlying social acceptance. A collaborative approach that integrates the perspectives of target communities to inform the design of EBRM initiatives according to the specific agro-ecosystem and socio-cultural context is necessary to ensure programmatic success

    Chromosomal evolution in tenrecs (Microgale and Oryzorictes, Tenrecidae) from the Central Highlands of Madagascar

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    Tenrecs (Tenrecidae) are a widely diversified assemblage of small eutherian mammals that occur in Madagascar and Western and Central Africa. With the exception of a few early karyotypic descriptions based on conventional staining, nothing is known about the chromosomal evolution of this family. We present a detailed analysis of G-banded and molecularly defined chromosomes based on fluorescence in situ hybridization (FISH) that allows a comprehensive comparison between the karyotypes of 11 species of two closely related Malagasy genera, Microgale (10 species) and Oryzorictes (one species), of the subfamily Oryzorictinae. The karyotypes of Microgale taiva and M. parvula (2n = 32) were found to be identical to that of O. hova (2n = 32) most likely reflecting the ancestral karyotypes of both genera, as well as that of the Oryzorictinae. Parsimony analysis of chromosomal rearrangements that could have arisen following Whole Arm Reciprocal Translocations (WARTs) showed, however, that these are more likely to be the result of Robertsonian translocations. A single most parsimonious tree was obtained that provides strong support for three species associations within Microgale, all of which are consistent with previous molecular and morphological investigations. By expanding on a recently published molecular clock for the Tenrecidae we were able to place our findings in a temporal framework that shows strong chromosomal rate heterogeneity within the Oryzorictinae. We use these data to critically examine the possible role of chromosomal rearrangements in speciation within Microgale. © 2007 Springer.Articl

    Anjozorobe Hantavirus, a New Genetic Variant of Thailand Virus Detected in Rodents from Madagascar

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    International audienceUntil now, there was only serological evidence that hantaviruses were circulating in rodents and infecting humans from Madagascar. To assess the presence of a hantavirus on the island, between October, 2008, and March, 2010, we sampled 585 rodents belonging to seven species in the Anjozorobe-Angavo forest corridor, 70 km north from the capital city Antananarivo. A hantavirus was detected from organs of the ubiquist roof rat (Rattus rattus) and of the endemic Major's tufted-tailed rat (Eliurus majori). Amazingly, sequence analysis of the S (small), M (medium), and L (large) coding DNA sequence of this virus showed that the Anjozorobe strain (proposed name) was a new genetic variant of Thailand virus (THAIV) that comprises other variants found in Southeast Asia. Because THAIV is suspected of causing hemorrhagic fever with renal syndrome in humans, ongoing studies are addressing the risk of infection by this new variant in the Malagasy population
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