Het verdwijnen van zoogdiersoorten

Some models of (especially Pleistocene) extinctions of larger mammals are outlined: Firstly, the species-exchange between North and South America after the two continents became connected in the Plio-Pleistocene and the subsequent disaster for the South American fauna. Secondly, the extinctions of insular faunas after the arrival of a continental fauna including man, with the examples of the Mediterranean islands and the Indonesian archipelago. The role of man as an important factor in past extinctions of larger mammals has either been stressed (e.g. MARTIN, 1984) or been largely denied by those who believe in climatic change with ensueing destruction of habitats as the main reason for extinctions (e.g. GUTRIE, 1984). Models allowing for both overkill by man and changes in habitat seem to be more realistic, although some of the habitat changes must have been caused by man. It may be clear that man cannot be ruled out as a weighty factor, as the case of Madagascar established. There is a marked difference between earlier and later extinctions, especially those occurring during the last 10000 years: species have stopped being replaced by others that are adapted to the same environment. This, no doubt, is entirely due to man.