Originally semi-nomadic, Shuars now live on and under the slopes of Andes in Ecuador. There is more than 40,000 of them. In the literature they are sometimes called jívaros and they are well known for their (now abandoned) practice of shrinking the heads of their killed enemies (tzantza). The aim of this practice was to gain control over the soul of the victim (muisak). Shuar shamans, called uwishin, also believe in and utilize tsentsaks (magical darts) to bring or fight illness. To acquire and learn how to manipulate tsentsak, they utilize natema (Ayahuasca vine) as well as datura and wild tobacco. According to their belief, it is important for each person to possess a the strong arutam (spirit), which is a force that, together with spirit-helpers such as the anaconda or the jaguar, help to journey in the Ayahuasca visions and heal the patients. In the process of shamanic appreticeship, the novice takes Ayahuasca to get in touch with the spirits. The novice also travels to sacred and powerful land spots such as waterfalls and take datura. The goal is to attain strong arutam. However, such rituals must be repeated throughout life if one loses the power of one's arutam.