25 research outputs found
Dietary flexibility of the greater bamboo lemur (Prolemur simus), a specialized feeder, in eastern Madagascar
The degree of dietary flexibility in primates is species specific; some incorporate a wider array of resources than others. Extreme interannual weather variability in Madagascar results in seasonal resource scarcity which has been linked to specialized behaviors in lemurs. Prolemur simus, for example, has been considered an obligate specialist on large culm bamboo with >60% of its diet composed of woody bamboos requiring morphological and physiological adaptations to process. Recent studies reported an everâexpanding list of dietary items, suggesting that this species may not be an obligate specialist. However, longâterm quantitative feeding data are unavailable across this speciesâ range. To explore the dietary flexibility of P. simus, we collected data at two northern sites, Ambalafary and Sahavola, and one southern site, Vatovavy, from September 2010 to January 2016 and May 2017 to September 2018, respectively. In total, we recorded 4022 h of behavioral data using instantaneous sampling of adult males and females from one group in Ambalafary, and two groups each in Sahavola and Vatovavy. We recorded 45 plant species eaten by P. simus over 7 years. We also observed significant differences in seasonal dietary composition between study sites. In Ambalafary, bamboo was the most frequently observed resource consumed (92.2%); however, nonâbamboo resources comprised nearly oneâthird of the diet of P. simus in Sahavola and over 60% in Vatovavy. Consumption of all bamboo resources increased during the dry season at Ambalafary and during the wet season at Vatovavy, but never exceeded nonâbamboo feeding at the latter. Culm pith feeding was only observed at Ambalafary, where it was more common during the dry season. We identify P. simus as a bamboo facultative specialist capable of adjusting its feeding behavior to its environment, indicating greater dietary flexibility than previously documented, which may enable the species to survive in increasingly degraded habitats
Conservation genomic analysis reveals ancient introgression and declining levels of genetic diversity in Madagascar's hibernating dwarf lemurs
Madagascarâs extraordinary biodiversity: Threats and opportunities
Madagascar's unique biota is heavily affected by human activity and is under intense threat. Here, we review the current state of knowledge on the conservation status of Madagascar's terrestrial and freshwater biodiversity by presenting data and analyses on documented and predicted species-level conservation statuses, the most prevalent and relevant threats, ex situ collections and programs, and the coverage and comprehensiveness of protected areas. The existing terrestrial protected area network in Madagascar covers 10.4% of its land area and includes at least part of the range of the majority of described native species of vertebrates with known distributions (97.1% of freshwater fishes, amphibians, reptiles, birds, and mammals combined) and plants (67.7%). The overall figures are higher for threatened species (97.7% of threatened vertebrates and 79.6% of threatened plants occurring within at least one protected area). International Union for Conservation of Nature (IUCN) Red List assessments and Bayesian neural network analyses for plants identify overexploitation of biological resources and unsustainable agriculture as themost prominent threats to biodiversity. We highlight five opportunities for action at multiple levels to ensure that conservation and ecological restoration objectives, programs, and activities take account of complex underlying and interacting factors and produce tangible benefits for the biodiversity and people of Madagascar
Madagascarâs extraordinary biodiversity: Evolution, distribution, and use
Madagascar's biota is hyperdiverse and includes exceptional levels of endemicity. We review the current state of knowledge on Madagascar's past and current terrestrial and freshwater biodiversity by compiling and presenting comprehensive data on species diversity, endemism, and rates of species description and human uses, in addition to presenting an updated and simplified map of vegetation types. We report a substantial increase of records and species new to science in recent years; however, the diversity and evolution of many groups remain practically unknown (e.g., fungi and most invertebrates). Digitization efforts are increasing the resolution of species richness patterns and we highlight the crucial role of field- and collections-based research for advancing biodiversity knowledge and identifying gaps in our understanding, particularly as species richness corresponds closely to collection effort. Phylogenetic diversity patterns mirror that of species richness and endemism in most of the analyzed groups. We highlight humid forests as centers of diversity and endemism because of their role as refugia and centers of recent and rapid radiations. However, the distinct endemism of other areas, such as the grassland-woodland mosaic of the Central Highlands and the spiny forest of the southwest, is also biologically important despite lower species richness. The documented uses of Malagasy biodiversity are manifold, with much potential for the uncovering of new useful traits for food, medicine, and climate mitigation. The data presented here showcase Madagascar as a unique living laboratory for our understanding of evolution and the complex interactions between people and nature. The gathering and analysis of biodiversity data must continue and accelerate if we are to fully understand and safeguard this unique subset of Earth's biodiversity
Conservation of Phylogenetic Diversity in Madagascarâs Largest Endemic Plant Family, Sarcolaenaceae
Megafrugivores as fading shadows of the past: extant frugivores and the abiotic environment as the most important determinants of the distribution of palms in Madagascar
The extinction of all Madagascar's megafrugivores ca. 1000 years ago, may have left its signature on the current distribution of vertebrate-dispersed plants across the island, due to the loss of effective seed dispersal. In this study, we dissect the roles of extinct and extant frugivore distributions, abiotic variables, human impact and spatial predictors on the compositional turnover, or beta-diversity, of palm (Arecaceae) species and their fruit sizes across 40 assemblages on Madagascar. Variation partitioning showed that palm beta-diversity is mostly shaped by the distribution of extant frugivores (8 lemur, 3 bird, 2 rodent and 1 bat species) and the abiotic environment (e.g., forest cover, slope and temperature), and to a lesser extent by the distribution of extinct frugivores (5 giant lemur and 3 elephant bird species). However, the contribution of these variables differed between dry western assemblages and wet eastern assemblages, with a more prominent role, albeit still small, of extinct megafrugivores in the west. These results suggest that palm distributions in the dry west of Madagascar, where megafrugivores were probably most abundant in the past, still show signatures of past interactions. With a fourth-corner analysis we observed that the distribution of palm species with relatively large fruits and seeds was negatively associated with home range of extant mammalian frugivores and frugivore richness of both past and extant communities, and positively associated with the hand-wing index (HWI) â a proxy for dispersal ability - of extant bird communities. This suggests that palm species with relatively large fruits tend to occur in places with fewer, small-ranged mammalian frugivores, which may indicate dysfunctional seed dispersal, although a few wide-ranging bird species may compensate this loss by dispersing the seeds of small-to medium-sized palm fruits. Our results shed new light on anachronisms in Madagascar, and how defaunation and past interactions may underlie current plant distributions.This data repository consists of the following folders and files:
Main folder
Word document containing information on each file and instructions for use (ReadMe.docx)
Excel document with 4 different sheets, containing supplementary tables S1, S2 and S3 and their references (TableS1_S2_S3.xlsx)
Supporting information for the manuscript (SupportingInformation.pdf)
"data" folder
Palm presence-absence data for each of the forty 0.3x0.3 grid cells (Palms_in_grid03.csv)
Palm dispersal-related trait data (maximum stem height in meters, average fruit length in millimeters, average fruit width in millimeters, average seed length in millimeters and average seed width in millimeters) for the 165 palm species appearing in the 40 grid cells (PalmTraits.csv)
Average climatic, soil and human variables per grid cell (Environment_grid03.csv):
Extant and extinct frugivore presence-absence data for each of the forty 0.3x0.3 grid cell (frugivore_extant_extinct_in_grid03.csv)
Extant and extinct frugivore dispersal-related trait data (frugivore_traits.csv): Body mass in kilograms, hand-wing index (HWI) and home range in hectares.
Geographic coordinates in Latitude and Longitude decimal degrees for the centroids of each of the forty 0.3x0.3 grid cell (centroids_grid03.csv)
Shapefile of the forty 0.3x0.3 grid cell created in QGIS 3.10.7 used to extract all the other values (0.3grid_20records)
Metadata
Average climatic, soil and human variables per grid cell (Environment_grid03.csv)
BIO1: Annual mean temperature (°C x 10)
BIO4: Temperature seasonality (standard deviation Ă100)
BIO6: Minimum temperature of the coldest month (°C x 10)
BIO12: Annual mean precipitation (mm x month-1)
pet: Annual potential evapotranspiration from the Thornthwaite equation (mm)
cwd: Annual climatic water deficit (mm)
alt: Altitude (in m)
slop: Slope in degrees
solar: Solar radiation (in Wh.m-2.day-1)
percfor2010: Madagascar's forest in 2010 was derived from the 30 m resolution 2000 forest map by Harper et al. (2007).
Clay: Soil clay content (0-2 micrometre) in g/100g (w%)
CationEC: Cation exchange capacity (CEC measured in 1 M NH4OAc buffered at pH 7) in cmolc/kg (fine earth)
Extractable_Aluminum: Extractable aluminium content (Al measured by Mehlich 3) in mg/kg (fine earth)
Total_Nitrogen: Total nitrogen (N) content in g/kg of the fine earth fraction
Total_Phosphorus: Total Phosphorus (P) content of the soil fine earth fraction in mg/kg (ppm)
Popdensity2010: "For all locations with more than 1000 people per kmâ2, we assigned a pressure score of 10. For more sparsely populated areas with densities lower than 1000 people·kmâ2, we logarithmically scaled the pressure score using: Pressure score = 3.333 Ă log(populationdensity+1)" (Venter et al. 2016).
HFP2009: Human footprint for 2009, calculated as a summary value from other several human-related variables such as built environments, population density, night-time lights, croplands, pasture, roads, railways, navigable waterways.
Roads: "We mapped the direct and indirect influence of roads by assigning a pressure score of 8 for 0.5âkm out for either side of roads, and access pressures were awarded a score of 4 at 0.5âkm and decaying exponentially out to 15âkm either side of the road" (Venter et al. 2016)
Funding provided by: Deutsche ForschungsgemeinschaftCrossref Funder Registry ID: http://dx.doi.org/10.13039/501100001659Award Number: DFGâFZT 118Funding provided by: Deutsche ForschungsgemeinschaftCrossref Funder Registry ID: http://dx.doi.org/10.13039/501100001659Award Number: 202548816Please refer to the Methods section and Supplementary Information of the published article