A recent study by international researchers has found that humans played a part in the extinction or near extinction of large groups of mammals during the Ice Age.

Among the victims were six large herbivores- the wooly rhinoceros, wild horse, reindeer, bison, musk ox and the wooly mammoth. The study by an international group of paleontologists, geologists, geneticists and climate modelers discovered that both climate change and the encroachment of man played a part in each species decline or extinction. The paper will be published in the scientific journal, Nature.

In each case the team had to dig through different types of data to determine why these six large herbivores disappeared or suffered a decline. The team collected genetic data from surviving member of the reindeer, bison and musk ox as well as climatic data and archeological data. The results showed that both climate change and humans contributed to some species extinction while in some cases only climate change was responsible. For example the wooly rhinoceros didn't interact with humans in Europe so data suggested that climate change was wholly responsible for the death of the wooly rhinoceros population.

As for the lucky reindeer, bison and musk ox scientists haven't been able to pinpoint why they survived and the other three species went extinct. Reindeer were able to find a safe haven in high arctic regions while bison have found a safe place in North America and Europe. Muskoxen were able to survive in the arctic regions of North America and Greenland.

"We couldn't pinpoint what patterns characterize extinct species, despite the large and varying amount of data analyzed," said Eline Lorenzen, from the University of Copenhagen and the first author of the study. "This suggests that it will be challenging for experts to predict how existing mammals will respond to future global climate change -- to predict which species will go extinct and which will survive."

Aside from these Ice Age species, there are other examples of human beings causing the extinction of animal species. This has been more prevalent in recent times with more than 5,000 species on the endangered list.