The 30 white rhinos were sent from South Africa to Akagera National Park in Rwanda, where they became the first of their kind to live there.
They are now “thriving well” and their numbers have grown to around 35 after new calves were born recently, said Drew Bantlin, an official at the park.
“All calves are growing and healthy. They are starting to move widely with their mothers and are showing normal behaviours,” he added.
The International Rhino Foundation (IRF) says the global white rhino population continues to decline under pressure from poaching.
In the last four years, the numbers have shrunk from around 18,000 to fewer than 16,000, the foundation says.