Giant pandas can live up to 30 years in captivity, but usually only 15 to 20 years in the wild.
Giant pandas are born tiny (about 100g or 4 ounces), blind, white and helpless. The mother cradles her tiny cub in a paw and doesn’t leave the den for several days after giving birth, even to drink.
Cubs soon develop soft gray fur, which becomes coarser and develops its black and white pattern in a month. See more on Baby Pandas.
Cubs rely on mother’s milk for the first year, but start to eat bamboo after six months. They can crawl at three months.
Cubs easily die in the wild because they are so small and defenceless. The mother has to leave them alone in the den to eat for four hours a day.
Giant pandas weigh about 45 kg (100 lb) at one year. Cubs live with their mothers for up to two years.
Giant pandas are fully mature and able to breed at six years old, while captive giant pandas are 2–3 years earlier.
An adult panda weighs 80–150 kilograms (176–331 lb). See Giant Panda Characteristics for more adult panda measurements.
Young male pandas have a lower priority in the wild, and barely have any opportunity to mate until 7 or 8 years old. Female pandas normally bear one cub every 2 or 3 years from 4 to 18 years old, if they live that long.
Giant pandas in captivity can be expected to live 30 years. The oldest panda ever recorded was 37 years old. Presently the oldest live panda is Jiajia in Hong Kong's Ocean Park. She'll be 36 on August 10, 2014.
The rate of reproduction is about one cub every two years.
Female giant pandas are only fertile once for two to three days a year (they're monestrous), sometime in the spring (March to May). They leave their partners after mating and rear their cubs alone.
Giant panda gestation is 3 to 5 months, and cubs are usually born in late summer in hidden hollow trees or natural dens, where branches, dry grass, etc. are made into a kind of nest.
Normally giant pandas give birth to a single cub (they're monotocous). Even if a female has two cubs, she would normally choose to take care of one and abandon the other.
In the wild the cub-bearing period for female giant pandas lasts for around 10 years. Therefore, a female panda is able to bear four to six cubs in her life at most.
Due to the low birth rate and vulnerability of cubs, it is little wonder that pandas are on the verge of extinction. A wild panda raises around five cubs in a lifetime, of which perhaps half die before reaching maturity, making the rate of pandas reaching adulthood just above the two needed to sustain the population.