During the late Pleistocene, a remarkably diverse assemblage of large-bodied mammals inhabited the "mammoth steppe," a cold and dry yet productive environment that extended from western Europe through northern Asia and across the Bering land bridge to the Yukon. Of the large predators--wolves, bears, and big cats--only the wolves and bears were able to maintain their ranges well after the end of the last ice age.
A new study led by researchers at the University of California, Santa Cruz, suggests that dietary flexibility may have been an important factor giving wolves and bears an edge over saber-toothed cats and cave lions.
"We found that dietary flexibility was strongly species-specific, and that large cats were relatively inflexible predators compared to wolves and bears. This is a key observation, as large cats have suffered severe range contractions since the last glacial maximum, whereas wolves and bears have ranges that remain similar to their Pleistocene ranges," said Justin Yeakel, first author of a paper on the new findings published in the Proceedings of the Royal Society B.
Yeakel, now a postdoctoral researcher at Simon Fraser University in British Columbia, worked on the study as a graduate student at UC Santa Cruz with coauthor Paul Koch, professor of Earth and planetary sciences at UCSC. The other coauthors are Paulo Guimares of the University of So Paolo, Brazil, and Herv Bocherens of the University of Tbingen, Germany.
The researchers based their findings on an analysis of stable isotope ratios, chemical traces in fossil bones that can be used to reconstruct an animal's diet. They used previously published stable isotope datasets to reconstruct predator-prey interactions at six sites located from Alaska to western Europe. The sites covered a range of time periods before, during and after the last glacial maximum, the period around 20 to 25 thousand years ago when the ice sheets reached their greatest
|Contact: Tim Stephens|
University of California - Santa Cruz