The Giant Pandas mature between the ages of four and eight in average (Wikipedia). For wild mature, female mature at the age of 5½ - 6½, and male mature at 6 –7 years (Edinburgh Zoo). For captivity pandas, they usually mature a year earlier (Edinburgh Zoo). Giant pandas’ mating season is between March and May (Wikipedia). This estrous cycle last for two or three days (Wikipedia). This occasion occur only once a year (Wikipedia). Then they are pregnant for 83-163 days, and 135 days is the average (CRIENGLISH). They usually give birth to two panda cubs (Smithsonian National Zoological Park). However, there is usually one survive (Smithsonian National Zoological Park).