Baby pandas, also known as cubs, are remarkably small when they are born, especially considering the size of adult pandas. A newborn giant panda cub typically weighs about 90 to 130 grams (3 to 5 ounces) and is about the size of a stick of butter, while an adult panda can weigh between 70 to 100 kilograms (154 to 220 pounds) or more. There are two primary reasons for this: Short Gestation Period: The gestation period of giant pandas is relatively short, averaging about 95 to 160 days. During this time, the embryo does not have enough time to grow and develop fully, leading to the birth of very small and underdeveloped cubs. Delayed Implantation: After fertilization, the fertilized egg in giant pandas does not immediately implant into the uterine wall. Instead, there is a period of delayed implantation, which means the embryo remains in a state of suspended development for a while. This delayed implantation reduces the actual time the embryo has to grow inside the mother's womb once implantation finally occurs, further contributing to the small size of the newborn cubs. Raising a tiny, underdeveloped cub requires less immediate energy investment from the mother compared to giving birth to a larger, more developed cub. The mother can conserve energy and allocate it to nursing and caring for the cub after birth.