Population structure, genetics and conservation of the maltese wall lizard, podarcis filfolensis, on linosa island (reptilia, lacertidae)

Abstract

Podarcis filfolensis is a lacertid lizard endemie to the Maltese and Pelagian archipelagos (Channel of Sicily). In Italy, this species occurs on Linosa and Lampione islands only, where the populations are referred to the endemic ssp. laurentiimuelleri. The Linosa population was studied using capture/recapture methods during two sampling seasons (1993, 2001), in order to analyse various ecological parameters and to assess habitat distribution and overall conservation status. A clear preference to xeric Mediterranean habitats dominated by Pistacia lentiscus was seen. The lizard density of the whole Linosa population, estimated by various methods, is extremely high. Molecular analyses (partial sequencing of mitochondria! tRNAphe and 12S rDNA genes) and electrophoretic analysis of 26 presumptive gene loci were also carried out on samples representing the three P. filfolensis populations from Malta, Filfola and Linosa islands. Both molecular and allozyme data indicate that the populations of the Maltese Archipelago (Malta and Filfola) are closely related to each other, and that these populations are genetically relatively differentiated from the Linosa population. High levels of genetic variability characterise the latter population. Recent observations of the species on Lampione Islet indicate that it is locally widespread and abundant Even though P. filfolensis does not seem to be threatened on either Linosa or Lampione, the populations occurring on these islands need to be regularly monitored as island populations are known to be more susceptible to change and extinction than mainland ones. © 2004 Taylor & Francis Group, LLC.