They were a nomadic people, whose livelihood was based on hunting, mainly birds, complemented with gathering berries, fungi and wild roots; along with some marine products.
Their perfected and elaborated arrowheads, more efficient than those of their predecessors, are one of their special characteristics.
The Selk'nam people are supposed to have been related to the Aonikenk or southern Tewelche people by a common branch, from which the first might have separated, occupying Tierra del Fuego.
Selk'nam is the name used by the nomadic people of Tierra del Fuego to identify their people and their culture. That is why this denomination is privileged, since the name Ona was given to them by the Yagán people and became popular after the colonization of the Austral territory, it did not come from the Selk´nam themselves.
This culture possessed a wide and diverse spiritual world manifested in ceremonies such as the Hain, a ritual initiation for adolescent males, in which certain secrets tending towards the preservation of the patriarchy were revealed.