Genetic and Demographic Consequences of a Rapid Reduction in Population Size in a Solitary Lemur

ABSTRACT

Population bottlenecks as a result of habitat fragmentation or other anthropogenic disturbances are increasingly common, but their consequences remain poorly studied. We studied the genetic population structure of a solitary nocturnal primate, Mirza coquereli, to investigate the demographic history of a local subpopulation in Kirindy Forest, western Madagascar, which showed recent dramatic fluctuations in population size. Additionally, we sampled the surrounding forest area to assess the genetic structure of the local population on a broader geographical scale. Analyses of mitochondrial DNA (mtDNA) and microsatellites of 53 individuals revealed that a recent reduction and subsequent recovery in population size (demographic bottleneck) in the local subpopulation did not result in a genetic bottleneck. Moreover, predicted matrilineal clusters and male-biased dispersal could be confirmed on a broader geographical scale by mtDNA analysis, but not by microsatellite analyses. These results suggest that a re-colonization of the demographic bottlenecked area took place. This study contributes to our knowledge of the genetic structure of solitary mammals and primates in particular and illuminates behavioral mechanisms, such as sex-specific dispersal, that influence the genetic structure of populations. Furthermore, we showed that populations of solitary mammals are able to compensate drastic local demographic changes via migration if habitat continuity at an appropriate scale is given.

Keywords:

BottlenecK, population dynamics, mtDNA-microsatellites, conservation, re-colonization, migration, Mirza coquereli.