Linking genetic diversity and temporal fluctuations in population abundance of the introduced feral cat (Felis silvestris catus) on the Kerguelen Archipelago.

Linking temporal variations of genetic diversity, including allelic richness and heterozygosity, and spatio-temporal fluctuations in population abundance has emerged as an important tool for understanding demographic and evolutionary processes in natural populations. This so-called ‘genetic monitoring’ was conducted across 12 consecutive years (1996-2007) at three sites for the feral cat, introduced onto the Kerguelen Archipelago fifty years ago. Temporal changes in allelic richness and heterozygosity at 18 microsatellite DNA loci were compared to temporal changes in the adult population abundance index, obtained by typical demographic monitoring. No association was found at the island spatial scale but we observed an association between genetic diversity and adult population indices from year to year within each study site. More particularly, the magnitude of successive increases or decreases in the adult population abundance index appeared to be the major factor linking the trajectori...