Since its beginning, the Minnesota Zoo has provided leadership in tiger conservation. Shortly after the Minnesota Zoo first opened, the first Species Survival Plan (SSP®), the Tiger SSP, was developed by Dr. Ulysses S. Seal. He was responsible for creating the first steps of a scientific approach to the management of an endangered species in captivity, using the tiger as a model. Today, most of the zoos of the world follow a similar plan for the management of many of their endangered species.Report on Tiger SSP Status (2010)
Three of six Panthera tigris subspecies - Amur (P.t. altaica), Malayan (P.t. jacksoni), and Sumatran (P.t. sumatrae) - are currently managed by the AZA Tiger SSP, as well as ‘generic’ tigers, which are subspecies hybrids. The Amur (Siberian) tiger population will be managed at the current level of 150 tigers, and each of the other two subspecies, Sumatran and Malayan, will be expanded up to a maximum of 150 tigers each. All subspecies will be managed to maximize the retention of gene diversity, but it is recognized that it may not be feasible to maintain 90% gene diversity over a 100-year program without substantial founder importation, particularly for the Sumatran and Malayan subspecies.
There are currently 137 Amur tigers in the AZA Tiger SSP. The target population size designated by the AZA Felid Taxon Advisory Group is 150. The current population has a relatively stable age distribution, with high survival and good reproductive success into the mid-teen years. Gene diversity increased from 1982 through 2001 due in part to periodic opportunistic importations from the European zoo tiger program (EEP) and Russia, and is now at 96.4% as compared to that of the wild tiger population. The long-term SSP goal is to retain at least 90% gene diversity for at least 100 years.
The Sumatran tiger SSP population consists of 70 individuals. The population is derived from 16 founders and retains 89.9 % gene diversity. The Malayan tiger SSP population is now at 55 tigers. This population is based upon 10 founders and currently retains 90.1 % gene diversity.
The generic tiger population in AZA-accredited zoos stands at 95 individuals. In 2009, the Tiger SSP initiated a process that seeks to phase out generic tigers to increase space for studbook-registered tigers. The Tiger SSP has recommended that AZA-accredited institutions should not breed, acquire, or transfer generic tigers without approval from the SSP.
Status of wild tiger populations
It has been estimated that as few as 3,500 tigers remain in the wild. This represents a 33% decline in the last decade. Maximum population size estimates for the different tiger subspecies are: Amur – 390, Bengal – 2300, Indochinese – 1230, Malayan – 500, and Sumatran – 230. South China tigers are thought to be extinct in the wild and may only survive in Chinese zoos. Probable causes of decline include poaching for tiger parts and skins, as well as habitat destruction and fragmentation.