29 research outputs found

    Anthropogenic landscape change and amphibian diversity in tropical montane biodiversity hotspots: insights from satellite remote sensing in the Madagascar highlands

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    The magnitude of anthropogenic landscape change in tropical montane biodiversity hotspots and its relationship with biodiversity is a global issue that remains ‘locked-in’ in the broad narrative of tropical change in Africa. Over a montane biodiversity hotspot of Madagascar highlands (Ankaratra Massif), we conducted analysis on land cover change with Landsat satellite sensor data to identify the magnitude of change (1995–2016) and on the habitat change–amphibian diversity relationship to understand links with biodiversity. The results evidenced that 17.8% of the biodiversity hotspot experienced change in land cover in only 20 years. That pressured the already threatened forests, particularly since 2005. Of the total forest area in 1995 (2062.7 ha), 21.5% was cleared by 2016 (1618.3 ha). Changes in forest cover followed a bidirectional pattern. While in the period 1995–2005, forests expanded at a rate of 2.0% year−1 (from 2062.7 to 2524.8 ha), the area declined between 2005 and 2016 at a rate of − 4.1% year−1, fourfold the rate reported nationally for Madagascar (− 1.1% year−1). Forest-to-shrubland transitions emerged as being of increasing concern to forest integrity. We identified a significant link between habitat change and amphibian diversity, but only for species richness. Counter to expectations, no significant relationship was found between species richness and deforestation rates, and between microendemism rates and any of the habitat change variables. Species richness responded to the spatiotemporal variability in vegetation dynamics represented by the standard deviation of the Normalized Differenced Vegetation Index (NDVI_std). Species richness was strongly negatively related to NDVI_std in the short-term (R2 = 0.91, p = 0.003) and long-term (R2 = 0.69, p = 0.03), increasing where the spatiotemporal variability in NDVI was lower. The magnitude of changes in this biodiversity hotspot suggests that region-specific assessments are necessary in the context of the tropical change narrative in Africa and should consider conservation policies tailored for local conditions. Reducing deforestation and land conversion rates through a management plan codesigned with local communities is urgent. Habitat change appears to impact on amphibian diversity by altering the functional attributes of the habitat and not just by reducing habitat extent. NDVI_std seems a relevant indirect metric for monitoring such change although other biophysical attributes obtained from satellite sensor data should be integrated and explored.info:eu-repo/semantics/acceptedVersio

    Ultraconserved elements-based phylogenomic systematics of the snake superfamily Elapoidea, with the description of a new Afro-Asian family

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    The highly diverse snake superfamily Elapoidea is considered to be a classic example of ancient, rapid radiation. Such radiations are challenging to fully resolve phylogenetically, with the highly diverse Elapoidea a case in point. Previous attempts at inferring a phylogeny of elapoids produced highly incongruent estimates of their evolutionary relationships, often with very low statistical support. We sought to resolve this situation by sequencing over 4,500 ultraconserved element loci from multiple representatives of every elapoid family/sub-family level taxon and inferring their phylogenetic relationships with multiple methods. Concatenation and multispecies coalescent based species trees yielded largely congruent and well-supported topologies. Hypotheses of a hard polytomy were not retained for any deep branches. Our phylogenies recovered Cyclocoridae and Elapidae as diverging early within Elapoidea. The Afro-Malagasy radiation of elapoid snakes, classified as multiple subfamilies of an inclusive Lamprophiidae by some earlier authors, was found to be monophyletic in all analyses. The genus Micrelaps was consistently recovered as sister to Lamprophiidae. We establish a new family, Micrelapidae fam. nov., for Micrelaps and assign Brachyophis to this family based on cranial osteological syn-apomorphy. We estimate that Elapoidea originated in the early Eocene and rapidly diversified into all the major lineages during this epoch. Ecological opportunities presented by the post-Cretaceous-Paleogene mass extinction event may have promoted the explosive radiation of elapoid snakes.Peer reviewe

    Descriptions of two new Spinomantis frogs from Madagascar (Amphibia, Mantellidae), and new morphological data for S. brunae and S. massorum ; American Museum novitates, no. 3618

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    22 p. : ill. (some col.), map ; 26 cm.Includes bibliographical references (p. 20-21).New collections of Spinomantis frogs (Amphibia, Mantellidae, Mantellinae) have been made by us in northern Madagascar, and based on these collections we here describe two new species. One species, from northeastern Madagascar, has reduced dermal spines on the limbs and resembles S. massorum, but is diagnosed based on features including its shorter snout, proportionally longer hind limbs, reduced foot webbing, and different coloration. The other species, from the Tsaratanana Massif, is most similar to S. peraccae, but can be diagnosed based on features including its much larger body size, more extensive foot webbing and different coloration. We also redescribe two other poorly known species of Spinomantis: S. brunae and S. massorum. Both these rare species had been recently described based on a single and pair of type specimens respectively, and we here report on the morphology of new comparative material. For both the new and redescribed species, we summarize information on behavior, habits, individual variation, and distribution, and we also present a morphological identification key for the entire Spinomantis genus, which now includes 12 species. The new species from the Tsaratanana Massif is known only from a single site (Befosa River). Because this site is not protected within a reserve, we propose this forest be considered for inclusion within the ongoing protected area expansion program for Madagascar

    A new phytotelmic species of Platypelis (Microhylidae: Cophylinae) from the Betampona Reserve, eastern Madagascar

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    We describe a new arboreal and diminutive species of the genus Platypelis from the Réserve Naturelle Intégrale N. 1 de Betampona, one of the last low-altitude rainforest fragments of eastern Madagascar. P. karenae sp. nov. is a phytotelmic species, living among leaves of Pandanus spp. and those of a herbaceous plant of the genus Crinum. Amongst species of comparable size, the new species is most similar to P. tetra, with which it shares a similar life history of occupying leaf axils of phytotelms. Phylogenetically, P. karenae is sister to P. tuberifera yet differentiated by a high level of genetic divergence (>7% p-distance for the analysed fragment of the 16S rRNA gene), its distinctly smaller size, acoustic repertoire, and colour pattern. The mitochondrial, nuclear, bioacoustic, and morphological data all independently support the validity of this new species.This research received support from the SYNTHESYS Project http://www.synthesys.info, which is financed by the European Community Research Infrastructure Action under the FP7 “Capacities” programme.Peer reviewe

    3_Code

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    Includes the following files: Code_Add_Tips_Test_Diversification_TESS.R Code_BPP_Dater.R Code_BPP_Maker.R Code_Character_Reconstruction.R Code_Match_Nodes_Dates_Among_Methods.R Code_Morlon_Model_Diversification.R Code_Reprojection_species_points.R Code_TESS_COMET_Modified.

    4_Shapefiles_Species_Coordinates_EcoRegions

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    Includes the following files: Madagascar terrestrial ecosystem shape files zip.zip MG_ecoregion_attribute_summary.csv species_coordinates.csv Yoder & Nowak (2006) _shapefiles.zi
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