Conservation biology of the European pond turtle, Emys orbicularis, in Italy: review of systematics and reproductive ecology patterns (Reptilia, Emydidae)

Abstract

The European pond turtle has been found to be a polytipic taxon characterised by some distinct genetic groups that embrace several morphological subspecies. Italian populations belong to at least two, perhaps to three different morphological groups. A special attention has been recently devoted to the study of reproductive strategies and body size relationships in Italian Emys orbicularis, found that both at a small and at a large latitudinal scale pond turtles may offer significant differences at a reproductive and at morphological level. Annual clutch frequency of Italian populations is on average double in most of the western Mediterranean area even if this pattern may be strongly influenced by climatic constraints. Northern European populations produce on average larger clutches than southern European pond turtle populations, but egg size does not vary within or between populations. Nesting areas are mainly south oriented, but may be located at a very variable distance from water, ranging from one to hundred meter distance. Predation is a constant pattern that averages on about 80–85% of digged nests, and does not appear as a biological constraints to Italian wild populations of the pond turtle.