Human hunters were not the only reason for the extinction of the giant wooly mammoth. The giant mammoths of Siberia and North America which used roam the planet for about 250,000 year, died away about 10,000 years ago due to climate change and shifting habitats, claim scientists.
The research reveals that while some dwarf mammoths survived on Wrangel Island in the Arctic Ocean until 3,700 years ago, the woolly mammoths (Mammuthus primigenius), covered in hair up to 20 inches (50 centimeters) long and possessing curved tusks up to 16 feet (4.9 meters) long, gradually disappeared from Siberia due to the climate change which resulted in the wiping out of large grasslands and increased temperatures from that of the Ice Age. Also, report has claimed that the humans used to be at harmony with the giant animal and therefore, they should not be targeted as the reason for the extinction of the mammoths.
Earlier, scientists used to consider ancient human hunters as the reason for death of the mammoths. Some even have developed a "Younger Dryas impact hypothesis" in which they reasoned that a meteor strike was a reason to drastically alter the North American climate and vanish the animals almost 12,900 years ago.
This time to study the reasons behind the gradual disappearance of the pachyderms, a team led by Glen MacDonald of the University of California, Los Angeles, conducted research on 1,323 wooly mammoth samples and numerous woodland sample records.
"Mammoths were open vegetation-adapted with diets dominated by graminoids and soft-shoots of selected woody plants such as willow. Conifer trees, although found in the stomachs of some woolly mammoths, are not nutritious browse. Birch (Betula) can be toxic to cecal digesters, such as mammoths, which lack a rumen for detoxification. While grasses and willows were plentiful, birch was less abundant ... In the north (from 60,000 to 25,000 years ago), with relatively abundant grass and willow cover, may represent an environment closest to the idealized mammoth steppe," says the study.
While describing what happened that caused the extinction of the mammoth, the research further adds "Small continental populations of woolly mammoth certainly were present after (12,900 years ag0), but trajectory of these populations towards extinction was being driven by changing habitat and perhaps also through human hunting that had spread to North America. Graminoid, willow and drier herbaceous cover decreased in concert with the establishment of deleterious birch shrubland/woodland throughout Beringia, development of extensive peatlands and wet tundra, and expansion of conifer forest including areas north of the modern treeline across Eurasia as far as the present coastline. Pressure from hunting was also present, as contemporary Paleolithic sites are numerous in both Siberia and now in northwestern North America. Modelling studies show that given the environmental stresses at the time, even limited hunting by humans could have significantly contributed to woolly mammoth extinction."
The report has been published in the current issue of Nature Communications.
