The giant panda lives alone for most of its life, only coming together with another of its species for long enough to mate. The panda’s diet leaves it with very little energy for moving or even for mating. Furthermore, female pandas are only fertile for two or three days a year, making it even more difficult for them to breed successfully.
A newborn panda cub is born hairless and blind, is about 15cm long and weighs only 100g, the smallest placental mammal of all in relation to the size of the adults. The cub will start to crawl after about 80 days and will stay with its mother for about 18 months, until it is able to establish its own territory. Pandas use a scent gland beneath their tails to mark their territories, using their tails as brushes.
Giant pandas give birth to twins in roughly half of their pregnancies but generally, only the strongest of the two cubs will survive in the wild. Since pandas store so little fat, the female is generally not able to produce enough milk to feed two cubs.
Photo: Erika Bauer/Smithsonian's National Zoo