Watch world's oldest panda mom giving birth to twins

Hong Kong celebrated the birth of its first two locally-born giant pandas on Thursday. Their mother, Ying Ying, set a record as the world’s oldest first-time panda mother. She gave birth to the twins at Ocean Park just a day before her 19th birthday, equivalent to 57 in human years. Ying Ying and her partner, Le Le, successfully mated naturally in March.

So, here’s all you need to know about panda’s birth facts:

A newborn panda cub weighs only 90-130 grams.
At birth, a cub is about 1/900th the size of its mother, making it one of the smallest newborn mammals relative to its mother's size.
Panda cubs rely on their mothers for the first few months and are fully weaned by 8 to 9 months.
Cubs typically leave their mothers around 18 months, when the mother becomes pregnant again.
In the wild, pandas have an average lifespan of 14-20 years, but they can live up to 30 years in captivity.