Human tribes on earth which are at the verge of extinction

A Maasai warrior. To be a Maasai is to be born into one of the world's last great warrior cultures, Nelson's website reads. The Maasai people, who live in Tanzania and Kenya, are said to have migrated to the region from Sudan in the 15th century.

The Samburu tribe lives in northern Kenya. Nelson told HuffPost that Samburu men are so powerful and at one with nature that they've been known to use their bare hands to kill lions that attack their camels.

The Nenets are reindeer herders who live in the Yamal peninsula of northwest Siberia. The Nenets have thrived in Siberia for more than a millennium, living in temperatures that range from minus 50 degrees Celcius in winter to 35 degrees Celcius in summer, per Nelson's website. Every year, the Nenets undertake a migration of over a 1,000 km, a distance that includes a 48 km crossing of the frozen Ob River.

The Nenets are reindeer herders who live in the Yamal peninsula of northwest Siberia. The Nenets have thrived in Siberia for more than a millennium, living in temperatures that range from minus 50 degrees Celcius in winter to 35 degrees Celcius in summer, per Nelson's website. Every year, the Nenets undertake a migration of over a 1,000 km, a distance that includes a 48 km crossing of the frozen Ob River.

Descendants of Turkic, Mongolic and Indo Iranian tribes, as well as the Huns, the Kazakhs are a semi nomadic people that have roamed the mountains and valleys of western Mongolia with their herds since the 19th century, per Nelson's website.

The Himba are an ancient tribe of tall, slender and statuesque herders, according to Nelson's website. Since the 16th century they have lived in scattered settlements, leading a life that has remained unchanged, surviving war and droughts...in one of the most extreme environments on earth.

The nomadic Mursi tribe lives in southwestern Ethiopia.

According to Nelson, the Huli tribe has shrunk by 90 percent in the last few decades, largely due to a mass migration to towns and cities.