Abstract
Field approaches (non-invasive sampling), laboratory approaches (genotyping of micro-satellites and sequencing of mitochondrial DNA) and recent theoretic developments (approximate Bayesian methods, simulations) will make it possible to analyze the impact of habitat fragmentation on lemur communities in Madagascar and in the archipelago of the Comoro Islands. The problem of the fragmentation and its impact on diversity on various geographic and temporal scales will be taken into account. The biological models will be lemur species belonging to two particularly endangered types (Propithecus and Eulemur), which our group has now been working on for over two years. Only species present in the north and northwest of Madagascar will be studied. Two species (Propithecus tattersalli and Eulemur fulvus fulvus) have already been subject to significant sampling and their genotyping has been initiated. A sample of Eulemur fulvus mayottensis (the brown lemur of Mayotte), whose origin has not been clearly established, has been obtained. The species that will be sampled during this project are: E. fulvus fulvus (present in the northwest and east of Madagascar), P. diadema perrieri and P. diadema candidus (sifaka species that are very endangered) as well as P. coquereli. The sampling of these species is simplified by the fact that the first two live in adjoining regions of P. tattersalli, while the latter is to be found in the northwest, in the same region as E. fulvus fulvus. The questions that are being raised are the following: (i) what is the impact of the recent habitat fragmentation on the genetic diversity of the sampled species, (ii) do the genetic data allow us to explain the dispersal of species of sifaka and brown lemurs in the northwest and the north of Madagascar, particularly in terms of past fragmentation (biogeographic zones etc), (iii) what is the origin of the brown lemur of Mayotte and (iv) how can one explain the astonishing polymorphism in the fur of the brown lemur of Mayotte, whose ancestral species seems to be E. fulvus fulvus which does not show this polymorphism. This project is based on the work carried out for over two years in collaboration with researchers at the University of Mahajanga and local NGO (Mayotte, the region of Darina) as well as international collaborations with colleagues working in Madagascar. The analysis of these genetic data will be done using already existing methods (see for instance Goossens and al.2006) or methods that will be developed. The fieldwork will continue in collaboration with the University of Mahajanga, within the framework of research projects, education and student training courses, as well as with local NGO (DAF in Mayotte, Fanamby in the north of Madagascar, CEPA in France), in order to raise awareness among the local communities, and define strategies of preservation based on quantitative criteria. The results of the genetic analysis will be useful to identify the forestry fragments that need to be dealt with urgently, identify groups of fragments that could be used on projects of translocation and propose priority corridors between isolated fragments. A PHVA (Population Habitat and Viability Analysis) will make it possible to produce a management plan for the studied areas. The status of the brown lemur of Mayotte could hence be enlightened.
France