As you make your way to the Northwest Territories of Canada via Great Bear Lake, you'll first come across thick spruce forests, which give way to Taiga or snow forests until you reach the Southern Arctic, which is known as the Sahtu region. It's also the place where the caribou species lived along with the Metis and Dene people, indigenous tribes of North America. These people have lived in harmony with the animals for millennia. Seemingly, they knew something about this reindeer species, which has so far been missed by science. So far, ecologists have discovered three varieties of caribou in the region, each with its unique habitat and lifestyle.

However, according to the Dene tribe, there are four such species, with a new study offering some support to this belief. Caribou is usually found in North America, but they sometimes move into Asia and Northern Europe, where they are known as reindeer.

Researchers have identified two subspecies of caribous, referred to as "woodland" and "barren ground" caribou. The latter is further divided into "boreal" and "mountain" groups, which although are genetically similar, lead different lifestyles. A study published in 2016 by Jean Polfus, an ecologist at the University of Manitoba, discovered that there was plenty of genetic mixing among the three groups of caribou, which hints that the same might be taking place in the Sahtu.

In his quest to know more about the animal, Polfus learned the Dene language and studied their history. He found that the Dene had indeed known another caribou species, known as the "todzi." According to the description, as laid down by these people, the fourth variety has a unique appearance and habitat besides their behaviors. Polfus gathered genetic samples of the species and found that they are genetically a unique group. The results were published in the journal Ecology and Society.