Adults of this solitary species have well-defined home ranges and rarely meet, except in the mating season that runs from March to May (5). During this time, pandas signal their presence by marking trees and banks with scent secreted from glands located beneath the tail (6). They will also strip bark and occasionally males will dust bathe; dust particles become covered with the pandas' scent and then waft into the air (6). Males also call during this time, and these can be heard echoing through the mountains (7). Females give birth to a single cub that is born in an extremely immature stage of development; weighing only a tiny fraction (0.001%) of their mother's weight (5). The female cares for her cub in a den located in the base of a hollow tree or in a cave for the first few months of its life (4) (8). Young pandas remain dependent on their mother for a year, by which time they are weaned, but usually remain with their mothers until they are two years of age and sometimes longer (4) (8). During this time, females may leave their cubs to forage for days at a time and in the past these supposedly 'abandoned' cubs were taken into captivity (4). Pandas are unusual amongst the larger mammals for the extreme specialisation of their diet, which depends almost entirely on bamboo. Bamboo is a relatively abundant food source but has poor nutritional value; adults must spend around 14 hours a day feeding (4), and need to consume between 10 and 20 kg over 24 hours (8). They therefore alternate periods of feeding and resting throughout the day and night (7). Bamboo is evergreen and in winter pandas concentrate on leaves and stems, descending to lower altitudes in search of new shoots in spring (6). Despite their specialisation on bamboo, pandas will readily scavenge on meat should they come across it (7).