Fine scale genetic structure in a population of the Prehensile Tailed Skink, Corucia zebrata

Abstract

The Prehensile-Tailed Skink (Corucia zebrata) (Scincidae) is endemic to the Solomon Archipelago, where it inhabits all major islands. The species is evolutionarily distinct and diverged from its nearest relatives during the Oligocene. To expand on the limited information available with respect to the life history and ecology of C. zebrata in the wild, we explored the species' prevalence to group living and the fine-scale genetic structure of a large and isolated population. Fifty-one lizards were sampled in a 900-ha study plot within a larger area of continuous rain forest on Ugi Island in the Solomon Islands, an area that represents approximately 20% of the C. zebrata habitat on the island. Using information from eight polymorphic DNA microsatellite loci, we conducted Bayesian assignment analysis and pairwise kinship estimates between individual lizards. No geographically induced subpopulation structure was detected. The majority of lizards were not found in immediate proximity of other individuals; however, pairwise kinship analysis showed that lizards located less than 150 m from each other were likely to share alleles identical by descent and, thus, were more related than by chance. Additionally, we found indications that individual lizards have moved several kilometers within the study area. We have uncovered information on dispersal and genetic structure in a large population of C. zebrata, a species whose natural habitat across the Solomon Archipelago is increasingly fragmented and degraded because of unsustainable logging.