Captured South African journalist Shiraaz Mohamed is alive in Syria and could be home within a month.
Their arrival heralds the zoo's new generation of lions, who haven't bred there in five years.
Agnes Maluleke, who is responsible for the management of the big cats at the zoo, in a northern Johannesburg suburb, says the new additions are exciting.
Male white lion Letaba and his two sisters Sabi and Jubba were born in April at a private game farm. They arrived at the zoo in July and were cared for in quarantine until recently. Letaba is the only sibling with a rare white coat inherited from his parents' recessive genes.
The zoo says it has seven adult lions that have all surpassed their natural life expectancy.