Reproduction
Initially the primary method of breeding giant pandas in captivity was by artificial insemination, as they seemed to lose their interest in mating once they were captured.The current reproductive rate is considered one young every two years.
Giant pandas reach sexual maturity between the ages of four and eight, and may be reproductive until age 20. The mating season is between March and May, when a female goes into her estrous cycle which lasts for two or three days and only occurs once a year.The gestation period ranges from 95 to 160 days.Cubs weigh only 90 to 130 grams (3.2 to 4.6 ounces), which is about 1/800 of the mother's weight.
If twins are born, usually only one survives in the wild. The mother will select the stronger of the cubs, and the weaker will die. It is thought that the mother cannot produce enough milk for two cubs since she does not store fat.The father has no part in helping raise the cub.