Small mammal fossil assemblages as indicators of environmental change in northern Corsica during the last 2500 years

The small Monte di Tuda cave is filled with a slightly disturbed, 2 m thick deposit. Very rich small vertebrate bone assemblages from barn owl pellets have been sampled extensively using special techniques to avoid contamination. Stratigraphical analysis and accelerator radiocarbon dating on the bones themselves both point to a rapid sedimentation rate during the last 2500 years, with a break in the building up of sediment between 1960 and 610 sp. Multivariate analyses of the frequencies of the small mammal species show that modern species had approximately the same ecology throughout the time sequence, and give, for the first time, an idea of the ecological preferences of the extinct endemic species of Corsica. The general development of the faunal spectra shows a general increase in human impact (clearance of the vegetation), through the sediment sequence. Other multivariate analyses indicate a sequence of at least three agricultural cycles: the first one during the Early Roman period, the second one between the Late Roman period (2-5th centuries AD) and the Pisa Peace (11-13th centuries AD), and the last one during the 14-19th centuries AD. The two earlier ones were mainly concerned with cereal cultivation, the later with tree cultivation. Whilst most of these cycles have only a local significance, two phenomena have a more extensive significance: (1) the immigration of Rattus rattus to Corsica and probably to the whole North-Western Mediterranean Basin, dated between the 4th-2nd centuries cal-sc; and (2) the mass extinction of the small endemic species, dating either to the Late Roman period or to the 11-13th centuries AD and probably resulting from large scale agricultural deforestation. In addition, the small mammal assemblages recovered appear to reflect a wetter climate at both the beginning of the sediment sequence (the ''small alpine glacial age'') and at the end (14-18th centuries: ''Petit age Glaciaire'' of Le Roy Ladurie). This paper gives an example of the importance of small mammal assemblages for reconstructing the environment in the historical period. (C) 1996 Academic Press Limited