Ten years into the marshes – Hapalemur alaotrensis conservation, one step forward and two steps back?

Natural resource management problems typically involve a multitude of stakeholders with diverse sets of needs and interests, and often conflicting worldviews in an environment with growing uncertainty. Such problems are termed “wicked” problems, where there are no right or wrong solutions, only more or less acceptable ones. In the case of Lake Alaotra, growing agricultural pressures have a negative impact on the wetland biodiversity and especially on the Alaotra gentle lemur (Hapalemur alaotrensis) restricted to these marshlands. The species survival is highly uncertain because of increased habitat loss caused mainly by marshland fires. The conservation work for this unique lemur is complex and complicated and requires the involvement and collaboration of decision-making institutions, NGOs, universities and riverine communities. From the inception of projects to their implementation phase, all parties need clearly defined responsibilities and transparency in communication in order to run projects successfully. This article describes the approach that Madagascar Wildlife Conservation has been implementing during the past ten years at Lake Alaotra, discussing the plan of action and challenges for environmental education, ecotourism and alternative livelihoods. Les problèmes de gestion des ressources naturelles impliquent généralement une multitude d’intervenants avec divers ensembles de besoins et d’intérêts, et souvent, les visions du monde contradictoires dans un environnement avec une incertitude croissante. Ces problèmes sont appelés problèmes sournois, ‘wicked problems’ en anglais, où il n’y a pas de bonnes ou de mauvaises solutions, seules plus ou moins acceptables. Dans le cas du lac Alaotra, la croissance des pressions agricoles a un impact négatif sur la biodiversité des zones humides, et en particulier sur l’Alaotra lémurien douce (Hapalemur alaotrensis) limitée à ces marais. La survie de l’espèce est très incertaine en raison de l’augmentation de la perte d’habitat causée principalement par les feux de marais. Les travaux de conservation pour ce lémurien unique sont complexes et compliqués, et nécessitent l’implication et la collaboration sur la prise de décision des institutions, des ONG, des universités et des communautés riveraines. Cela implique que toutes les parties, depuis la création de projets à leur phase de mise en oeuvre, partagent un terrain d’entente avec les avantages clairement définis de pouvoir de décision, les responsabilités et la transparence dans la communication. Madagascar Wildlife Conservation a travaillé sur le lac depuis plus de dix ans, y compris l’éducation environnementale, l'écotourisme et les moyens de subsistance alternatifs dans le plan d’action. Cet article met en évidence l’approche adoptée et examine ses défis

Use of Mangroves by Lemurs

Despite an increasing recognition of the ecosystem services provided by mangroves, we know little about their role in maintaining terrestrial biodiversity, including primates. Madagascar’s lemurs are a top global conservation priority with 94 % of species threatened with extinction, but records of their occurrence in mangroves are scarce. I used a mixed-methods approach to collect published and unpublished observations of lemurs in mangroves: I carried out a systematic literature search, and supplemented this with a targeted information request to 1243 researchers, conservation and tourism professionals and others who may have visited mangroves in Madagascar. I found references to, or observations of, at least 23 species in five families using mangroves, representing more than 20 % of lemur species and over 50 % of species whose distributions include mangrove areas. Lemurs used mangroves for foraging, sleeping and travelling between terrestrial forest patches, and some were observed as much as 3 km from the nearest permanently dry land. However most records were anecdotal and thus tell us little about lemur ecology in this habitat. Mangroves are more widely used by lemurs than has previously been recognised, and merit greater attention from primate researchers and conservationists in Madagascar

Small-scale coexistence of two mouse lemur species (Microcebus berthae and M. murinus) within a homogeneous competitive environment

Understanding the co-occurrence of ecologically similar species remains a puzzling issue in community ecology. The species-rich mouse lemurs (Microcebus spec.) are distributed over nearly all remaining forest areas of Madagascar with a high variability in species distribution patterns. Locally, many congeneric species pairs seem to co-occur, but only little detailed information on spatial patterns is available. Here, we present the results of an intensive capture–mark–recapture study of sympatric Microcebus berthae and M. murinus populations that revealed small-scale mutual spatial exclusion. Nearest neighbour analysis indicated a spatial aggregation in Microcebus murinus but not in M. berthae. Although the diet of both species differed in proportions of food categories, they used the same food sources and had high feeding niche overlap. Also, forest structure related to the spatial distribution of main food sources did not explain spatial segregation because parts used by each species exclusively did not differ in density of trees, dead wood and lianas. We propose that life history trade-offs that result in species aggregation and a relative increase in the strength of intra-specific over inter-specific competition best explain the observed pattern of co-occurrence of ecologically similar congeneric Microcebus species