A new study discovered that the wooly mammoths perished due to unavailability of their food which was caused by the sudden appearance of grasslands throughout the Arctic region.

According to the study led by Eske Willerslev from the University of Copenhagen, the wooly mammoths and their source of food, dubbed as the "megafauna" which flourished in Siberia and other northern plains in the North America, perished after the end of the Ice Age which paved the way for warmer climate. The warmer, wetter climate was friendlier to grass, which slowly dominated the region and drove the mammoth's source of food into extinction.

The team analyzed the DNA samples of Arctic vegetation and found that 10,000 years ago, the species of plant called forbs, which were characterized by their broad leaves and flowers, disappeared from the steppes in the Arctic. Since then, the Arctic region which was once flourished with tansies, mums, and yarrow, were dominated by grass. The samples used by the researchers were taken from areas in Alaska, Canada, and Russia.

The results of the new research were surprising for other scientists because before, it was theorized that the mammoths favored grass as their source of food. However, after analyzing the scat and stomach content taken from mammoths and other animals such as reindeer, elk, horses, and wooly rhinos, it was found out that the forbs were a staple in the animal's food consumption.

Willerslev stated to the National Geographic that previous research might have missed the connection between the forbs and the animals' diet because their methodology heavily relied on protein count. He argued that forbs could also provide enough amounts of protein for the mammoths and they were easier to digest than grass.

The researchers also claimed that the mammoths played a role in preserving the vegetation of their habitat by helping dispersing the seeds and producing manure for fertilizing the plants. However, the transition from forbs to grass was sped up by human hunters who contributed to the population decline of the mammoths.

For Russia's director of Northeast Science Station Sergey Zimov, the claims made by the study are "preliminary conclusion". Zimov, who was not involved in the study, noted that there may be some DNA overlaps that reflect the number of forbs which lived after the Ice age has ended and the number of animals involved in the study was limited.

The study was published in the Feb. 5 issue of Nature.