The two siblings, Henko and Eso, were saved from a harrowing life in Albania before being brought to Scotland.
Thought to have been poached after their mother was shot, they were kept in a small roadside cage beside a restaurant.
Severely malnourished and forced to survive off rain water collecting in puddles at the side of the cage, they were rescued by a charity organisation in Albania.
Brian Curran, who owns Five Sisters with his wife Shirley, told the BBC: “We are delighted to welcome Henk and Esco to the zoo.
“While they did not have a very good start in life, we are sure that the young bears will settle well in to their new enclosure and given the right environment and care, will become true bears.”