The Sumatran tiger is the only surviving tiger population in the Sunda Islands, where the Bali and Javan tigers already extinct. The species is listed as "Critical Endangered" on the Red List. Zoos like the Frankfurt Zoological Garden try to breed them. The success is very important for the preservation. Since 2017, there is a new male. But he doesn't harmonize with the female. Therefore, it's necessary to exchange with other zoos to preserve this rare animal.