Thirty-three lions removed from circuses in Peru and Colombia will be in Africa by next week after spending years in South America.
Two dozen of the lions were rescued from Peruvian circuses during surprise raids organised by Animal Defenders International (ADI) that says they were living in deplorable conditions.
Another nine lions were handed to the group by a Colombian circus.
The wildlife advocacy group has worked with authorities to crack down on illegal wildlife use and trafficking in order to rescue the animals.
ADI President Jan Creamer said the scope of the operation sends a clear message to people around the world.
"This is a hugely important rescue mission because it does make a statement around the world about the way people treat animals and about our relationship with the other species who share our planet. This is their planet too; they have the right to live here and the way they are treated by humans is incredibly bad and we need to change the way we treat other animals. So it's important for that reason. It's a statement about the importance of showing respect and compassion to other species but also it shows people that we can make a change," she said.
Almost all of the lions have had their claws removed and many have broken teeth. One lion has lost an eye and another is almost blind, making it impossible for them to survive in the wild.
Veterinarian Eva Chong said the animals cared for at the ADI Rescue Centre in Lima have made good progress.
"Here at the ADI Rescue Centre, we have 24 lions, including 7 female and 17 male lions. Some arrived in 2014 and have been here over a year and a half. The last ones that arrived last year, in April, so they have been here about one year. These animals came to us in varying conditions but the good thing is that they have been recovering here with us. Many of them came from circuses," she said.
On Friday, an MD11F cargo aircraft will travel to the Colombian capital city of Bogota to pick up nine lions. Then, it will fly to Lima, Peru to collect the other 24 lions before heading to Johannesburg in South Africa.
A team of animal specialists from ADI will travel with the lions to assess their well-being during the long flight.
The animals will be taken to the Emoya Big Cat Sanctuary in South Africa where ADI officials said they will enjoy natural enclosures with drinking pools, platforms and toys.
Over the next few months, animal specialists will monitor the lions' adaptation and gradually introduce them to each other.
The lions are just the latest of a number of wild animals rescued and relocated by ADI.
The wildlife group has already relocated bears, monkeys, birds and other native wildlife to sanctuaries in Peru and a tiger to one in the United States.
According to ADI, it will cost US$10,000 to transport each lion. They are still accepting donations.