In a viral video, taken by a GoPro camera, the so-called "
The lions are now 10 years old.
Despite all of this time living in the wild in South Africa, the lions still respond to Richardson's voice. He calls the animals' names and they come running to greet him.
Richardson's methods are controversial since interacting with wild animals is obviously dangerous.
But on his website, Richardson argues that developing personal relationships with lions brings attention to their plight in captivity and the wild.
A large study published in the journal
You can watch Richardson stroking and kissing his lion friends like house cats in the video below: