Two baby orangutans found in Kutai National Park after being abandoned by their mother are being taught the skills they will need for life in the wild.

The brothers, three-year-old Dami and 10-month-old Rizki, were in critical condition when they were found. Surabaya Zoo keepers and the Centre for Orangutan Protection have since been nursing them back to health, treating them for malnourishment and injuries.

Orangutans have the longest childhood of any animal (apart from humans), often staying with their mothers until they are six or seven years old. They are completely dependent on their mothers for the first two years of their lives, and are only weaned at about five years old or when their mother gets pregnant again.

Surabaya Zoo is working to improve its standards of care. Hundreds of animals have died in the last four years, prompting an international campaign to shut it down.