April to May is the breeding season. Female and male pandas will have their rare moments together. After May, they drift apart. When the female one is 4-5 months pregnant, she will be anxious to find a hollow tree or cave as the delivery room. When the cub is born, she will raise her baby by herself.
Animals of the bear family (including seven existing species of bears and one species of giant panda) usually have very low cub to mother weight ratio. This ratio of giant pandas is at the lowest 1:1,000 to 1:1,500. The newborn's weight only about 150g (0.33 pounds), which is approximately one thousandth of their mothers’ weight. One month after birth, they will weigh 2kg (4.4 pounds), then reach 5-6kg two months later. According to existing records, the smallest newborn cub was only 51g (0.11 pound) and the biggest one weighed 247g (0.54 pound).
Lovely Baby Pandas of Six-month Old
The newborn cubs are weak and can not stand. For their first two months, they hardly move, except being fed and sleeping. At four months old, they have eyesight and can move a little with poor motor coordination. They can run a little, tumbling and crawling up to their mother’s back. Half a month later, they like to be active, mimicing their mother’s movements of eating bamboo, although they can not eat yet. When the cubs are half a year old, they can eat some bamboo and gain weight quickly.
Giant pandas will leave their mother and live alone when they are 1.5 to 2 years old.
Infant pandas are immature when they are born, equivalent to 4-6 months of human embryos. They do not have cerebral sulcus in the brain, white corpuscles in the blood and a sound renal function. It is hard to determine the gender of the cub. Their eyes and ears are not mature either - only small prominences. The establishment of their immune defense entirely relies on breast feeding for the first few days.