A massive reduction in grasslands and the spread of forests may have been the primary cause of the decline of mammals such as the woolly mammoth, woolly rhino and cave lion, according to Durham University scientists.
The findings of the new study challenge the theory that human beings were the primary cause of the extinction of mammals through hunting, competition for land and increased pressure on habitats.
The research is part of the most comprehensive study to date of Northern Hemisphere climate and vegetation during and after the height of the last Ice Age, 21,000 years ago. It shows that, over a huge part of the Earth's surface, there was a massive decline in the productivity and extent of grasslands due to climatic warming and the spread of forests.
These habitat changes made grazing much more difficult for large mammals and dramatically reduced the amount of food available for them. The changes in grassland quality and availability coincided with increases in the distribution and abundance of modern man, Homo sapiens, ensuring a time of wide-scale upheaval for herbivorous mammals and other mammals that preyed on them.
The decrease in productivity and extent of grassland is likely to have been the major contributor to the extinction of many large mammals across most of northern Eurasia and north-western North America by about 11,400 years ago, the onset of the present warm interglacial period. Although some species held on for several thousand years longer in very limited localities, their fate had effectively been sealed.
Professor Brian Huntley, from the School of Biological and Biomedical Sciences at Durham University, said: "Woolly mammoths retreated to northern Siberia 14,000 years ago whereas they had roamed and munched their way across many parts of Europe, including the UK, for most of the previous 100,000 years or more.
"The change from productive grasslands across large areas of northern Eur
|Contact: Carl Stiansen|