NATURAL HYBRIDIZATION IN PODARCIS-SICULA AND P-WAGLERIANA (REPTILIA, LACERTIDAE)

An allozyme survey revealed instances of natural hybridization between Podarcis sicula and P. wagleriana from the Aegadian and Aeolian islands (Sicily). Pure specimens of both species together with F, hybrids were found on Vulcano (Aeolian Islands) and Marettimo (Aegadian Islands). Limited evidence of backcrossing was detected on Marettimo. The two hybrid zones were interpreted as secondary overlap zones, being due to the relatively recent extension of the range of P. sicula into the peripheral range of P. wagleriana. On both islands, hybrids were found only in areas of habitat disturbance. At Lipari (Aeolian Islands) some specimens morphologically recognized as P. sicula had an Idh-1 allele typical of P. wagleriana, although the latter species is not known from the island. This may result from past hybridization and introgression, followed by the extinction of P. wagleriana on the island. Natural hybridization between P. sicula and P. wagleriana was not evidenced on the island of Favignana and in Sicily.