the spiritual world or dimension. Most shamans have dreams or visions that convey certain messages. Shamans may claim to have or have acquired many spirit guides, who they believe guide and direct them in their travels in the spirit world. These spirit guides are always thought to be present within the shaman, although others are said to encounter them only when the shaman is in a trance. The spirit guide energizes the shamans, enabling them to enter the spiritual dimension. Shamans claim to heal within the communities and the spiritual dimension by returning lost parts of the human soul from wherever they have gone. Shamans also claim to cleanse excess negative energies, which are said to confuse or pollute the soul. Shamans act as mediators in their cultures. Shamans claim to communicate with the spirits on behalf of the community, including the spirits of the deceased. Shamans believe they can communicate with both living and dead to alleviate unrest, unsettled issues, and to deliver gifts to the spirits. Among the Selkups, the sea duck is a spirit animal. Ducks fly in the air and dive in the water and are thus believed to belong to both the upper world and the world below. Among other Siberian peoples, these characteristics are attributed to waterfowl in general. The upper world is the afterlife primarily associated with deceased humans and is believed to be accessed by soul journeying through a portal in the sky. The lower world or "world below" is the afterlife primarily associated with animals and is believed to be accessed by soul journeying through a portal in the earth. In shamanic cultures, many animals are regarded as spirit animals. Shamans perform a variety of functions depending upon their respective cultures; healing, leading a sacrifice, preserving traditions by storytelling and songs, fortune-telling, and acting as a psychopomp ("guide of souls"). A single shaman may fulfill several of these functions. The responsibilities of a shaman may include either guiding to their proper abode the souls of the dead (which may be guided either one-at-a-time or in a group, depending on the culture), and the curing of ailments. The ailments may be either purely physical afflictions—such as disease, which are claimed to be cured by gifting, flattering, threatening, or wrestling the disease-spirit (sometimes trying all these, sequentially), and which may be completed by displaying a supposedly extracted token of the disease-spirit (displaying this,