A time-lapse video has captured the first 100 days of two giant panda cubs born in the United States.
Mei Lun and Mei Huan were born at Zoo Atlanta in July this year and the three-minute video, which has been viewed nearly 250,000 times, documents their development.
In the first 100 days the cubs, who were the first twins to be born in the US and survive, go from tiny pink, blind and toothless creatures to pandas with thick black and white hair.
The names Mei Lun and Mei Huan, which comes from a Chinese phrase meaning "something indescribably beautiful and magnificent", were revealed at a naming ceremony on the 100th day of their lives.
When cubs are born they are about 900 times smaller than their mothers and spend a lot of time sleeping after the birth as their eyes develop.
It is only after around 75 days the cubs begin crawling and a zoo keeper from Atlanta said the pandas are now trying to stand-up.
The pair are the fourth and fifth offspring of pandas Lun Lun and Yang Yang and zoo staff will rotate the pandas with their mother so one is not neglected.
Zoo Atlanta said in the YouTube comments:
– Zoo Atlanta
In the wild, giant panda moms typically care for only one cub when twins are born.
Thus, it is normal in the wild for only one of the twins to survive. Giant panda twins have survived in zoos within and outside of China.
Usually this is accomplished by rotating the cubs with the mother for the first few months.
However, giant pandas are born very tiny, and there is a high risk of mortality in the first few months.
The video documenting the cubs first 100 days comes after keepers at Edinburgh Zoo said their giant panda Tian Tian was not pregnant.
Experts believe the panda, who was artificially inseminated, had a miscarriage.