Aspects of the biology of Podarcis Filfolensis

Abstract

This study describes the results of three years' work on the distribution, habitat preferences, feeding, activity patterns, spatial behaviour, reproductive behaviour, defense from predators and caudal autotomy in the Maltese wall lizard (Podarcis filfolensis). Taxonomy and conservation biology are also briefly discussed. From snout-vent-length data it was found that males are larger than females, and that the lizards of the island of Filfola are the largest of all the Maltese Islands, followed by those of General's Rock, Pelagian Islands, Malta and St. Paul's Islands in that order. It was also found that the snout-vent-lengths are statistically different between the different subspecies except between Podarcis filfolensis maltensis (Malta and Gozo) and P. f. kieselbachi (St. Paul's Islands). Male and female Maltese wall lizards are both territorial and commonly have a core area in which they spend about 68% of their active time. Females have a smaller home range than males. Males and females form partnerships to defend their territory. Agonistic behaviours occur, especially during the breeding season. The costs and benefits of caudal autotomy are discussed. 88% of Filfola lizards examined were found to have regenerated tails. This is interpreted to be a result of high predation pressure on the islet. In order to conserve this endemic species of lizard, walls should be safeguarded as they form its principal habitat.