A rare Sumatran rhino has been born at a sanctuary in Indonesia.

The calf, which has not yet been named, weighed 25kg (55lb).

Sumatran rhinos are the smallest of all rhinos, and are classed as critically endangered.

Successful births are to be celebrated, as there are only around 40 of the animals left in the world – on the Indonesian islands of Sumatra and Borneo, global conservation charity WWF says.

They used to be found in Bhutan, India, Myanmar, Thailand, and possibly further afield.