Day-time feeding ecology of Eulemur cinereiceps in the Agnalazaha Forest, Mahabo-Mananivo, Madagascar

The Agnalazaha Forest, a degraded fragment of littoral forest in southeast Madagascar, contains a small population of the endangered Eulemur cinereiceps. To better conserve this species its feeding ecology was described by habituating two groups and recording their activities, the food types and species exploited, and the location of food trees by focal animal sampling. The lemurs’ environment was also described by measuring forest structure, and monitoring climate and phenology. In total, the groups were observed for 498 hours over 11 months. Monthly time spent feeding averaged 9.6% of total observation time. The species was highly frugivorous (93% of total time spent feeding). 55 different plant species were exploited for food. Time spent feeding and diet were not simply related to rainfall and temperature nor to food type availability. The two groups’ home ranges were 54.9 ha and 58.4 ha and showed a 40% overlap. The overlap occurred in the swamp forest, which is rich in food plants. To improve the conservation of E. cinereiceps at the Agnalazaha Forest, it is recommended that: The swamp forest be included within the zone of strict conservation; important lemur food plants used for restoration; and alternative sources of timber and fuel wood provided for the local population, thereby allowing greater forest regeneration.RÉSUMÉ La forêt d’Agnalazaha est un bloc de forêt littorale dégradée d’une superficie de 1,500 ha dans le sud est de Madagascar qui abrite une petite population de l’espèce en danger Eulemur cinereiceps. L’écologie de ce lémurien n’a jamais été étudiée dans les forêts littorales et pour améliorer la protection de cette espèce prestigieuse, l’écologie de son régime alimentaire a été étudiée en habituant deux groupes et en relevant la nature des activités, le type de nourriture consommé, les espèces consommées et la localisation des arbres source de nourriture par focal animal sampling. L’environnement d’ E.cinereiceps a également été décrit avec des informations portant sur le climat, d’une part, et d’autres portant sur la structure de la forêt, sa composition et la phénologie en utilisant deux parcelles de 1 ha de forêt dans lesquelles tous les arbres dont le tronc avait un diamètre au moins égal à 10 cm ont été relevés, identifiés et suivis quant à leur fructification et floraison mensumensuelles. La structure et la composition de la forêt d’Agnalazaha se sont révélées typiques des forêts littorales malgaches. Au total, les groupes de lémuriens ont été observés pendant 498 heures au cours d’une période de 11 mois. La durée mensuelle moyenne consacrée à l’alimentation était de 9,6% de la durée totale des observations. L’espèce s’est montrée nettement frugivore (93% de la durée totale consacrée à l’alimentation) mais elle consommait également des feuilles, des inflorescences, des fleurs, du nectar, des insectes et des champignons. Les feuilles et les nectars ont pu être des composants importants du régime alimentaire à certaines périodes. Un total de 55 espèces de plante ont été consommées, parmi lesquelles Noronhia emarginata, Pandanus microcephalus, Garcinia verrucosa et Uapaca louvelii étaient les plus courantes. Le temps consacré à l’alimentation et celui alloué à la consommation des divers aliments n’étaient liés ni au climat ni à la disponibilité de la nourriture. Les superficies des territoires occupés par les deux groupes étaient de 54,9 ha et de 58,4 ha et présentaient un chevauchement de 40% au niveau de la forêt marécageuse où les plantes consommées à titre de nourriture étaient abondantes. Pour protéger E. cinereiceps dans la forêt d’Agnalazaha, nous recommandons que la forêt marécageuse soit incluse dans une zone de conservation stricte ; que les plantes importantes faisant partie du régime alimentaire de ces lémuriens soient considérées dans les activités de restauration de la forêt ; et que des sources alternatives pour l’obtention de bois d’oeuvre ou de chauffe soient proposées à la communauté villageoise locale pour permettre à la forêt de se régénérer

Fire and the reproductive phenology of endangered Madagascar sclerophyllous tapia woodlands

AbstractTapia woodland vegetation is a remnant of Madagascar sclerophyllous forest that has developed under the selective pressure of fire and is dominated by the endemic tree Uapaca bojeri (Phyllanthaceae), locally named tapia. We carried out a 2-year study in tapia woodland at Ibity mountain, a new protected area in central highlands of Madagascar. We aimed to describe the reproductive phenology of this vegetation type and to determine whether it is affected by fire. We addressed two main questions: 1) does fire frequency affect the proportion of reproducing individuals and the intensity of each flowering and fruiting event?; and 2) does fire frequency influence the reproductive synchrony of species across the landscape? Thirteen woody species (373 individuals) were sampled at six sites selected across the Ibity mountain, where three that were burned three times between 2000 and 2010 and three burned just once during the decade. We found that (1) fire reduced the percentage of individuals that participate in each phenophase, and flower and fruit production was lower at the more frequently burned sites; and (2) increased fire frequency reduced the reproductive synchronization of species throughout the landscape. Fire is recognized as one of the major disturbances affecting mortality and recruitment of trees in tapia woodland. Our study indicates that fire also impacts the timing of plant reproduction at community and landscape levels

Weak Lensing of the CMB by Large-Scale Structure

Several recent papers have studied lensing of the CMB by large-scale structures, which probes the projected matter distribution from $z=10^3$ to $z\simeq 0$. This interest is motivated in part by upcoming high resolution, high sensitivity CMB experiments, such as APEX/SZ, ACT, SPT or Planck, which should be sensitive to lensing. In this paper we examine the reconstruction of the large-scale dark matter distribution from lensed CMB temperature anisotropies. We go beyond previous work in using numerical simulations to include higher order, non-Gaussian effects and study how well the quadratic estimator of \cite{Hu01a} is able to recover the input field. We also study contamination by kinetic Sunyaev-Zel'dovich signals, which is spectrally indistinguishable from lensed CMB anisotropies. We finish by estimating the sensitivity of the previously cited experiments.Comment: 26 pages, 13 figures, replaced to match the minor revisions of the accepted versio

The XXL Survey: : XXIX. GMRT 610 MHz continuum observations

Accepted for publication in a forthcoming issue of Astronomy & Astrophysics. Reproduced with permission from Astronomy & Astrophysics. © 2018 ESO.We present the 25 square-degree GMRT-XXL-N 610 MHz radio continuum survey, conducted at 50 cm wavelength with the Giant Metrewave Radio Telescope (GMRT) towards the XXL Northern field (XXL-N). We combined previously published observations of the XMM-Large Scale Structure (XMM-LSS) field, located in the central part of XXL-N, with newly conducted observations towards the remaining XXL-N area, and imaged the combined data-set using the Source Peeling and Atmospheric Modeling (SPAM) pipeline. The final mosaic encompasses a total area of 30:4 square degrees, with rms <150 μJy beam -1 over 60% of the area. The rms achieved in the inner 9.6 square degree area, enclosing the XMM-LSS field, is about 200 μJy beam -1, while that over the outer 12.66 square degree area (which excludes the noisy edges) is about 45 μJy beam -1. The resolution of the final mosaic is 6.5 arcsec. We present a catalogue of 5434 sources detected at ≥7 × rms. We verify, and correct the reliability of, the catalog in terms of astrometry, flux, and false detection rate. Making use of the (to date) deepest radio continuum survey over a relatively large (2 square degree) field, complete at the flux levels probed by the GMRT-XXL-N survey, we also assess the survey's incompleteness as a function of flux density. The radio continuum sensitivity reached over a large field with a wealth of multi-wavelength data available makes the GMRTXXL- N 610 MHz survey an important asset for studying the physical properties, environments and cosmic evolution of radio sources, in particular radio-selected active galactic nuclei (AGN).Peer reviewedFinal Accepted Versio

The Canadian Cluster Comparison Project: weak lensing masses and SZ scaling relations

The Canadian Cluster Comparison Project is a comprehensive multi-wavelength survey targeting 50 massive X-ray selected clusters of galaxies to examine baryonic tracers of cluster mass and to probe the cluster-to-cluster variation in the thermal properties of the hot intracluster medium. In this paper we present the weak lensing masses, based on the analysis of deep wide-field imaging data obtained using the Canada-France-Hawaii-Telescope. The final sample includes two additional clusters that were located in the field-of-view. We take these masses as our reference for the comparison of cluster properties at other wavelengths. In this paper we limit the comparison to published measurements of the Sunyaev-Zel'dovich effect. We find that this signal correlates well with the projected lensing mass, with an intrinsic scatter of 12\pm5% at ~r_2500, demonstrating it is an excellent proxy for cluster mass.Comment: 14 pages, 5 figures, submitted to MNRA

Damage to tropical forests caused by cyclones is driven by wind speed but mediated by topographical exposure and tree characteristics

Each year, an average of 45 tropical cyclones affect coastal areas and potentially impact forests. The proportion of the most intense cyclones has increased over the past four decades and is predicted to continue to do so. Yet, it remains uncertain how topographical exposure and tree characteristics can mediate the damage caused by increasing wind speed. Here, we compiled empirical data on the damage caused by 11 cyclones occurring over the past 40 years, from 74 forest plots representing tropical regions worldwide, encompassing field data for 22,176 trees and 815 species. We reconstructed the wind structure of those tropical cyclones to estimate the maximum sustained wind speed (MSW) and wind direction at the studied plots. Then, we used a causal inference framework combined with Bayesian generalised linear mixed models to understand and quantify the causal effects of MSW, topographical exposure to wind (EXP), tree size (DBH) and species wood density (ρ) on the proportion of damaged trees at the community level, and on the probability of snapping or uprooting at the tree level. The probability of snapping or uprooting at the tree level and, hence, the proportion of damaged trees at the community level, increased with increasing MSW, and with increasing EXP accentuating the damaging effects of cyclones, in particular at higher wind speeds. Higher ρ decreased the probability of snapping and to a lesser extent of uprooting. Larger trees tended to have lower probabilities of snapping but increased probabilities of uprooting. Importantly, the effect of ρ decreasing the probabilities of snapping was more marked for smaller than larger trees and was further accentuated at higher MSW. Our work emphasises how local topography, tree size and species wood density together mediate cyclone damage to tropical forests, facilitating better predictions of the impacts of such disturbances in an increasingly windier world

Madagascar’s 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