A dolphin released into the wild has taught her friends how to walk on their tails.
Dolphin
Billie the bottlenose learned the trick while she was in captivity after being rescued from a badly polluted creek 30 years ago and housed with other animals at a dolphinarium in Adelaide.
Now, she's passed on the trick - which sees her 'standing' upright on her tail and running backwards over the waterline - to nine of her friends.
According to a new study in the Royal Society's Biology Letters, Billie has continued to perform it since her release into the wild.
Other dolphins started copying her in 2011, and scientists say it's the only known example of a mammal teaching human tricks to its peers out in the wild with no involvement from a trainer.
It's also been suggested that this sign of intelligence could also save the species from climate change, according to experts at the University of Exeter and the Whale and Dolphin Conservation.
Dr Mike Bossley, the study's lead author, said: ''I knew Billie's history and was able to track her behaviour and that of the other dolphins in the community over an extended period.
''This enabled me to observe tail walking spread through the community and then its eventual fading away.''