Red pandas are predominately solitary, and are most active at dawn and dusk (5). They have semi-retractable claws, which allow them to be efficient climbers and when not foraging, pandas are usually found in the trees. Males occupy territories that overlap those of several females, especially in the mating season (4), and territories of both sexes are marked with anal secretions (5). Red pandas mate on the ground but the female gives birth, usually to two young, within a hollow tree nest cavity (5). Young are born blind and helpless, opening their eyes after 18 days; their coat is initially grey-buff in colour (5). Red pandas are one of the few animals whose diet is composed almost entirely on bamboo; they grasp stems with their forepaws and shear the leaves off with sharp teeth (4). Bamboo is poor in nutrients; to compensate, red pandas are only active for around 56 % of the day (4) and have an extremely slow metabolism, which is comparable to that of the sloth (7). Other foods such as roots and fruit as well as small lizards and bird's eggs are also eaten (2). Red pandas have an ungainly walk on the ground but are much more agile in the trees, using their tail for balance although it is not prehensile; on the ground the tail is carried horizontally away from the body (5). After eating or resting the red panda will tend to groom itself thoroughly (5).