Persistence and dispersion of an introduced population of Alpine Newt (Triturus alpestris) in the limestone plateau of Larzac (Southern France)

The study of introduced populations is interesting to better understand the geographic distribution and adaptability of species in different environments. The recent finding of an Alpine Newt population (Triturus alpestris) in the limestone plateau of Larzac (Department of Herault, France) provides the opportunity to examine the success of this species in the French supra-Mediterranean environment, Indeed, this species is absent from southern France although present in a large part of France and in northern Spain. The introduction site and all water bodies within a 2.5 km radius were surveyed between spring and autumn 2003. Because of the introduction date and the life expectancy of newts, all observed individuals are descendants of the introduced animals. They persist and breed in the study site despite the coexistence with Palmate Newts (Tri-turus helveticus). Body condition decreases in summer in these two species, but was lower in Alpine Newt males than in Palmate Newt males in autumn. Alpine Newts were found in only one of the other nine ponds, indicating a 1.5 km dispersion. Few Alpine Newts were present at this site, but reproduction was effective. These results show that the Alpine Newt can survive in southern France despite the presence of other newt species, but that the dispersion speed and rate towards other ponds are low.