Lepilemur mittermeieri, an endangered species from Northwestern Madagascar: ecology and conservation challenges.

Tropical forests are home to the widest variety of organisms, currently estimated at around 50% of all species on the planet. They also provide important ecosystemic services, particularly in terms of global climate regulation, storage of vast amounts of carbon and oxygen production. Unfortunately, they are also extremely threatened by increased anthropogenic pressure, both direct and indirect. Indeed, deforestation and habitat fragmentation are considered to be the main threats to biodiversity today. Madagascar, one of the world’s main “hotspots” of biodiversity, has not been spared; about 90% of the island’s forest cover has disappeared and the current deforestation rates remain very high. The Island, a world priority in terms of conservation material, is notably home to an endemic group of primates, lemurs, who are completely linked to their forest habitat and for whom the state of conservation is particularly alarming. This research project focuses on the impact of forest fragmentation on a strictly tree-dwelling species of primate in Madagascar. The study model, Lepilemur mittermeieri, is a small, little-known, folivorous and nocturnal primate, who is threatened with extinction (IUCN, 2012) and is restricted to the Ampasindava peninsula, north-west of Madagascar. This lepilemur is completely dependent on the forests of the peninsula, whose area is continuously shrinking under anthropogenic pressure. L. mittermeieri can be considered the archetype of a tree-dwelling species of primate with small distribution areas and whose habitat is threatened. The general objective of this research is to explore the ecology of L. mittermeieri and the conservation issues related to its preservation. This work is based on three specific objectives: one, to collect the first data on this species; two, to understand habitat use by L. mittermeieri; and three, to examine the future of the species in a fragmented forest environment. This work is therefore carried out on two scales, that of the individual and that of the distribution area, the Ampasindava peninsula. At the individual scale, we studied the species ecology by focusing on the range and sleeping sites features, as well as the diet of the species and the social structure. By radio-tracking, we were able to follow about twenty individuals and highlight that the average range of L. mittermeieri is around 2 ha. We identified, on average, 4.7 sleeping sites per individual, mostly clusters of vegetation, always occupied by a single individual and almost never shared over time. Sleeping sites are mainly located in the core area of the home range. L. mittermeieri diet is diverse, with a minimum of 77 vegetable species, some of which are more commonly consumed. The species seems rather solitary, but not especially territorial as ranges overlap, even between males. At the scale of the Ampasindava peninsula, this study shows that L. mittermeieri is found in fragments of different size, altitude and forest type. We found a density of 1.4 individuals/ha, which could represent a total population of some 10.000 individuals if the hypothesis of homogeneity within different forest fragments is confirmed. This first estimate must be taken with precaution. We also calculated an increasing rate of deforestation on the peninsula, reaching 3.14%/year between 2000 and 2014. This is confirmed by a significant reduction in the number of forest core areas and increasing fragmentation. L. mittermeieri is present in narrow forest strips indicating that the species still has the resources to survive. There is no obvious indication that the long-term survival of the species is assured. To conclude, this work highlights the extent and speed of deforestation and fragmentation of forest habitats on the Ampasindava peninsula. The recent development of a rare earth mining project is increasing the pressure on biodiversity in this region. This work emphasizes the importance and the urgency of implementing an action plan for the conservation of L. mittermeieri

Influence of host plant species on Borocera cajani larval development: a case study using tapia (Uapaca bojeri) and voafotsy (Aphloia theaeformis)

le ver à soie sauvage Borocera cajani appartenant à la famille des Lasiocampidae et communément appelé par les malgaches landibe. Il s’agit d’un insecte holométabole, endoptérygotes, polyphage et dont la croissance larvaire se fait par l’intermédiaire de cinq mues successives suivies d’une métamorphose complète au stade nymphal avant d’aboutir au stade adulte, le papillon nocturne. L’habitat principal du landibe sont des forêts principalement composées d’une espèce végétale endémique à Madagascar : le tapia (Uapaca bojeri, Euphorbiaceae). Cet écosystème forestier a pendant longtemps été perturbé et menacé. Aujourd’hui, dans la région d’Arivonimamo, des procédures pour assurer sa protection sont mises en place et les Associations Communautaires de Base (COBA) se chargent de les faire respecter. Ce document se focalise sur l’étude du cycle larvaire de B. cajani et de l’influence de deux plantes nourricières, le tapia et le voafotsy (Aphloia theaeformis), sur son développement. Des essais comportementaux visant à démontrer les préférences alimentaires ont également été réalisés. Les résultats obtenus nous ont permis de mettre en évidence l’influence de la plante nourricière sur certains paramètres du cycle de développement du landibe. La comparaison d’élevages en conditions naturelles et en laboratoire a montré une influence du milieu sur la taille des individus. Enfin, nous avons montré que les larves élevées sur voafotsy montrent une préférence pour cette plante hôte, lorsque mises en présence de voafotsy et de tapia. Les publications et les connaissances scientifiques actuelles sur Borocera cajani sont encore trop superficielles. La présente recherche apporte donc des informations supplémentaires et essentielles sur la connaissance de la chenille du landibe, qui, pour ne pas être vouée à disparaître dans la zone d’Arivonimamo, devrait bénéficier d’un statut légal de protection.Many plant and animal species are endemic in Madagascar. Among them, the silk moth Borocera cajani, commonly named landibe, and which belongs to the Lasiocampidae family. It is a pholyphageous insect, with five larval stages followed by a complete metamorphosis in the pupal stage to turn into an adult; a nocturnal butterfly. Landibe’s principal habitat is composed of an endemic plant species in Madagascar: tapia (Uapaca bojeri, Euphorbiaceae). For a long time, this ecosystem was disturbed and seriously threatened. Today, in the area of Arivonimamo, procedures to ensure its protection exist and the “Associations Communautaires de Base” (COBA) are in charge of their respect. Activities related to silk industry can consist in important incomes for many families in the area of Antananarivo, increasing their standard of living. This research aims at increasing our general knowledge on Borocera cajani and more especially on its larvae cycle. We studied the influence of two feeding plants; tapia and voafotsy (Aphloia theaeformis), on several parameters of larvae development cycle, and we compared wild and laboratory breeding. Preference tests have also been carried out in the laboratory. Results showed that feeding plants have influence on some of the parameters of the landibe’s cycle development. Wild and laboratory breeding comparison revealed an influence on animals’ size. Preference tests showed that larvae, which grow up on voafotsy, developed a preference for this feeding plant. Current publications and scientific knowledge on Borocera cajani are still too small. This study brings complementary and essential information on landibe, which should receive legal protection status in order to avoid its disappearance

Updated population density estimation and distribution range of the Critically Endangered Sahamalaza sportive lemur, Lepilemur sahamalaza

peer reviewedAccurate population density estimates are important for effective conservation measures of endangered species. For the Critically Endangered Sahalamaza sportive lemur (Lepilemur sahamalaza), no recent or robust population estimates are available, complicating conservation management of this species. This study examined the species distribution range as well as assessing population density in the range of occurrence with standardized methodology (transect walks and home range calculations) between 2013 and 2016. The results suggest that Sahamalaza sportive lemurs are confined to the Sahamalaza Peninsula. Population density ranges between 1.49 to 1.87 individuals/ha depending on the methodology used to estimate density. Population size estimates consequently vary between 3800 and 4700 remaining individuals of this species, subject to a re-evaluation of the remaining habitat

Species richness and speciation in the genus Lepilemur in northwestern Madagascar

Sportive lemurs of the genus Lepilemur are small, nocturnal folivorous lemurs that are exclusively arboreal and generally have small distribution ranges. Owing to these characteristics, they are particularly negatively affected by deforestation and habitat fragmentation, which is reflected by the recent uplisting of many of the 26 Lepilemur species into one of the threatened categories of the IUCN Red List. The main aim of this study is to understand the evolutionary mechanisms underlying species richness and speciation processes of the genus Lepilemur in northwestern Madagascar, and to test the predictions of the Inter-River-System biogeographic model of lemur distribution patterns proposed by Olivieri et al. (2007). This study focuses particularly on three Lepilemur taxa: L. sahamalazensis, L. dorsalis and L. mittermeieri, which have their distribution ranges in the northwestern regions of Sofia and Diana. The objectives are to determine their exact distributions, currently unknown; to assess the allopatry or parapatry for L. dorsalis and L. mittermeieri; and to explain the barrier between these two taxa if it exists. A second fundamental aspect of the project consists in the development of noninvasive tools, based on species-specificity of bio-acoustic structures, which will allow species identification in the field. This paper discusses the results from a two-month preliminary field season, conducted from 1st April to 31st May 2013 in order to explore the mainland forests located between the Andranomalaza (Maetsamalaza) and Maevarano rivers. We established the presence/absence of Lepilemur in different forest fragments of this poorly-known area and collected information about land use classes and land use change using remote sensing techniques

Conservatisme de niche et biologie de la conservation dans le nord-ouest de Madagascar

The main goals of our study is to verify the existence and extent of niche conservatism in three closely related species within the genus Lepilemur, and to draw conclusions on the applicability of conservation protocols to a broader array of Lepilemur species. The genus is an exemplary of the mammalian fauna of Madagascar which high biological diversity is under increasingly severe threat from anthropogenic degradation of its forest habitats. This study focuses particularly on three poorly-known Lepilemur taxa: L. sahamalazensis, L. dorsalis and L. mittermeieri, uplisted into one of the threatened categories of the IUCN Red List.The genus is particularly negatively affected by deforestation and habitat fragmentation and all have a small distribution range, fairly small total populations. Their pattern of distribution appears to have been established through vicariant speciation, probably driven by changes in the configuration of the hydrographic system. Such a pattern permits to expect a high level of niche conservatism. We present here our preliminary results of an exploratory mission on 1) evaluation of Lepilemur abundance in forest patches on the Ampasindava Peninsula, the Sahamalaza Peninsula and the Manongarivo Special Reserve 2) sleeping sites characteristics of the three studied species