How did environmental disturbances affect carnivoran diversity? A case study of the Plio-Pleistocene Carnivora of the North-Western Mediterranean

The Plio-Pleistocene carnivores from the North-Western Mediterranean (Iberian and Italian peninsulas, and France) are analysed in order to investigate whether their diversity over the last 5.3 Ma was influenced by disturbances of the physical environment. Trends in species diversity over time were analysed in successive unequal time intervals, which were reassessed on the basis of local biochronological schemes. By using a taxon-free characterisation, species were assigned to various ecological categories in accordance with feeding and hunting behaviour, preferred habitat, and average body mass. Principal Component Analysis identified the most important ecological variables in recognising changes among the carnivoran Faunal Complexes that characterised each time interval. The results obtained support the hypothesis that some complex, though not always direct relationships exist between environmental changes and shifts in the diversity of Carnivora (especially for forest dwelling carnivorans). However, progressive changes in carnivoran guilds cannot be interpreted as merely a response to climate changes, because intrinsic biotic control (changes in inter-specific and intra-specific competition) also plays an important role in modifying carnivoran diversity. Therefore, climate change seems to trigger the various factors that contribute to the reconstruction of carnivoran palaeocommunities.