Biological Invasions

, Volume 15, Issue 9, pp 2029–2037

An impact assessment of the alien lizard Plestiodon japonicus (Scincidae, Reptilia) on a threatened island population of the native lizard P. latiscutatus at an early phase of the biological invasion

Original Paper

DOI: 10.1007/s10530-013-0429-8

Cite this article as:
Okamoto, T., Kuriyama, T. & Goka, K. Biol Invasions (2013) 15: 2029. doi:10.1007/s10530-013-0429-8

Abstract

On the island of Hachijojima, central Japan, a formerly abundant population of native lizard, Plestiodon latiscutatus has become endangered by predation from an alien weasel (Mustela itatsi). Recently, an alien lizard, P. japonicus, became established on the island. The impact of the alien lizard and current distribution of the native lizard were assessed by field surveys and DNA analyses. The native lizard was sparsely distributed in the western part of the island. The alien lizard occurred in the northeastern region of the island. Between these regions, several hybrid populations were identified, including some with non-F1 genotypes, suggesting that introgression is occurring. The distribution of the weasel was examined based on field observations, allowing us to estimate predator impacts on both lizard species. We found evidence that the weasel was present throughout the entire island, suggesting that the alien lizard was able to become established despite the presence of the weasel. This indicates that the alien lizard is likely to expand its habitat range and that introgression may spread. We conclude that P. latiscutatus populations will become increasingly endangered by the synergism of genetic introgression from P. japonicus and predation pressure from the weasel.

Keywords

Impact assessmentIntrogressionIsland invasionDNA

Copyright information

© Springer Science+Business Media Dordrecht 2013

Authors and Affiliations

  1. 1.Department of Zoology, Graduate School of ScienceKyoto UniversitySakyo-kuJapan
  2. 2.Department of Biology, Faculty of ScienceToho UniversityFunabashiJapan
  3. 3.Invasive Alien Species Research TeamNational Institute for Environmental StudiesTsukubaJapan