Caribou, the North American name for reindeers, graze in the tundra during the Arctic summer until the end of September, before moving southward to the wintering areas of the boreal forests. They must then walk on ice, in soft snow or mud and swim across bodies of water. They use their hooves, at the origin of their Indian name 'xalibu': the one who uses its hooves as a shovel, not only to scratch the snow and access the lichens they feed on but also as oars, crampons or snowshoes during these trips.