Genetic Diversity and Management Units for Conservation of West Coast Oligosoma (Reptilia: Lacertilia: Scincidae)

Abstract

The West Coast region of the South Island of New Zealand has been largely unsureveyed for herpetofaunal diversity. Preliminary investigations raised questions about the genetic distinctiveness of some West Coast skinks in the genus Oligosoma, especially those from Chesterfield, Big Bay, and the Open Bay Islands. Assessment of genetic diversity to allow the identification of management units and taxonomic units (species) within the West Coast skink fauna were the central aims of this study, as a first step to effective conservation management. Gene products were analysed for 15 enzyme (allozyme) loci in the West Coast skinks. The results indicate that there are six species of skinks extant on the West Coast. Three of these are undescribed taxa, here labelled as: O. "Big Bay", O. "Grey Valley" and O. "Open Bay Islands". Oligosoma "Big Bay" and O. "Grey Valley" are described in this study, but O. "Open Bay Islands" remains undescribed due to a lack of material of this species. The other species present in the West Coast region are O. infrapunctatum, O. zelandicum, and O. nigriplantare polychroma. The West Coast populations of O. infrapunctatum may deserve treatment as a separate management unit for conservation. Little is known of the population status or ecology of the species of skinks endemic to the West Coast. Now that their taxonomic status has been clarified, ecological investigations should be the highest priority for conservation management. Other conservation needs include the investigation of threats facing the skinks, and assessment of population numbers to determine the need for actions such as removal of skinks for captive breeding, or the establishment of reserves.