6533b821fe1ef96bd127b750

RESEARCH PRODUCT

Population Genetics, Parasitism, and Long-Term Population Dynamics of Microcebus murinus in Littoral Forest Fragments of South-Eastern Madagascar

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description

Habitat fragmentation is a major threat for lemur conservation, as it reduces population sizes to levels that are nonviable in the long term. Alternatively, isolated populations may have great importance for conservation, as some are well protected and some lemurs do well even in small areas. Hence, knowing which characteristics indicate a population under threat is of paramount importance for conservation action. We studied Microcebus murinus populations confined to forest fragments of different sizes and states of degradation in south-eastern Madagascar to investigate relationships between population size, population dynamics, genetic diversity of coding and noncoding DNA, and infection rates by gut parasites. Population sizes decreased with decreasing fragment size and with increasing degradation. Population dynamics sampled over 9 years (equivalent to 9 generations in the littoral forest fragments) suggested a constant decline over time but several populations recovered unexpectedly, indicating substantial fluctuations in population size rather than a systematic trend. Sex ratios and parasite loads did not differ significantly between populations living in fragments of different size and degradation. Genetic diversity of noncoding DNA decreased with declining population size, but the diversity of the major histocompatibility complex, selected for high variability to act against parasites, did not differ between populations.