The red deer is the largest mammal in the Krkonoše Mountains, with around 650 individuals living on the Czech side. When there is insufficient food for the deer in the wild during winter, they gnaw on and strip the bark from trees, which damages the forest, particularly its natural regeneration. To protect the forest, the deer are kept in winter enclosures where they are fed and monitored for health. There are 18 such enclosures in the mountains, operated by the KRNAP Administration for over twenty years, and located in remote areas so as to minimise visitor disturbance to the animals.