Zootoca vivipara carniolica Common lizard Berna convention, ann. 3 The name "viviparous" indicates that the development and hatching of eggs occurs within the body of the mother and the young are born self-sufficient. The viviparous lizard populations that are found in lowland habitats are closely related to some characteristic, such as fens dominated by the presence of Schoenus nigricans. Recent studies have shown that populations of viviparous lizard found in the plains are special: they are not viviparous but oviparous, meaning that lay eggs like other lizards. For this reason they are considered a subspecies called Zootoca carniolica vivipara. It is likely that these low altitude areas, the overall extension of suitable habitat for the species, estimated in excess, does not even reach the twenty square kilometres. Lizard populations, in each site they live, can be considered in danger of extinction because of habitats fragmentation. The few acres of habitat suitable for the fragility and instability that characterize them, represent a naturalistic emergency which should be protected with high priority. The species is widespread in the Alps, but the isolated populations of this lizard found in peat bogs of the lower Friuli plain are considered residues of those who inhabited the plain during the glacial period. For this reason it is called glacial relict species. 
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