Among the extant non-flying terrestrial mammals of the Mediterranean islands, we can find very few of the endemic elements that characterised the late Quaternary faunas. Instead, the existing faunas are almost exclusively dominated by continental taxa, as a rule regionally specific, related to species on the nearest mainland, and whose presence on the islands appears to be essentially related to human intervention. The legacy of this global reorganisation of the original ecological equilibrium brought about by man since prehistoric times raises considerable problems of conservation and management. First of all, in the vast majority of cases, it is impossible to reconstruct the natural ecosystems of the past, which have been degraded for millennia. However, this leaves the question of how to treat the anthropochorous mammalian populations of certified ancient origin. Several of them, in fact, represent invaluable historic documents. Frequently, they may also constitute the last survivors of continental populations which themselves vanished long ago. Their protection and their study can provide an opportunity for testing a range of different evolutionary theories, while also allowing them to be considered as an authentic “cultural heritage".