Management and Conservation of Captive Tigers, Chapter 8

Regional and Global Management of Tigers

R. Tilson, K. Traylor-Holzer and G. Brady

Introduction to a Species Survival Plan (SSP)

c Taman Safari IndonesiaSpecies Survival Plans are cooperative management programs of the American Zoo and Aquarium Association (AZA) for selected species. The purpose of these programs is to reinforce, not replace, wild populations. All too often the general public expects individuals of endangered species at their local zoo to be released back into the wild. This is not the case. Rather, the captive population needs to be perceived as a reservoir of genetic material (that represents the species, not just individuals) that can periodically be used to re-establish populations that have been lost within their natural range or to revitalize wild populations that have become depressed by genetic and demographic problems.

The birth of an SSP depends on the convergence of two significant issues. The first is the recognition that a particular species is in desperate need of protection beyond the traditional process of trying to maintain its security in its natural environment. Factors important in the selection process include how threatened the species is, the likelihood of its success in captivity, and the probability of putting enough individuals together to have an effective program. Input from the World Conservation Union's (IUCN) various specialist groups (for cats it is called the Cat Specialist Group) is integrated with other relevant information to make these decisions. Once the AZA has approved the species for inclusion in an SSP (this step is under the authority of the Wildlife Conservation and Management Committee), member zoos already possessing individuals of the species are solicited. Those that agree to participate in the program form an eight-member (or smaller) Management Group. This group then begins developing the masterplan.

The masterplan is the core of the SSP. This document provides institution-by-institution and animal-by-animal recommendations on mate selection, animal relocations (from zoo to zoo for better breeding combinations), breeding, and surplussing (when an animal is no longer needed for breeding, either for genetic or demographic reasons), and finally, technical and financial support for programs that advance the conservation of the tiger in its natural range.

The strength of an SSP masterplan depends on the accuracy of the biological database for every animal within the program. Usually this database is maintained as a Regional Studbook using a computer software program called SPARKS (Single Population and Records Keeping System) produced by ISIS (International Species Information System). The studbook database is initiated from ISIS data, a computerized database containing genetic, demographic and relevant biological information about zoo animals worldwide. After this database is checked against existing studbooks, questionnaires are sent to participating institutions requesting verification. Once verification is accomplished, the Management Group can begin serious planning for their particular species. A series of complicated demographic and genetic analyses needs to be performed before the Management Group can start making recommendations. SPARKS automatically calculates inbreeding coefficients (IC), which indicate the relatedness of an individual animal's parents (probability that an animal will become homozygous at a given locus by descent). Basically, SSPs strive to avoid inbreeding, which may lead to reduced fertility, increased mortality, and loss of genetic diversity, thereby limiting the species' options to respond to environmental variation.

Another concern in determining breeding recommendations in a managed population is to equalize the representation of each "genetic line" in the population. An animal is referred to as a "founder" if it represents a new genetic line to the population (i.e., has no relatives in the population). The founders of a zoo population are either the original wild-caught animals or imported animals not genetically represented in the SSP from whom the current population is descended. It is presumed that founders are unrelated to each other and represent a reasonably well-distributed genetic sample of the species in the wild. In an ideal situation, each founder would be equally represented in the living SSP population. This is seldom the case—typically, a large proportion of the animals have descended from a few prolific founders who have many more living descendants than other founders and are thus more fully represented in the population's gene pool. The challenge of the SSP Management Group is to make breeding recommendations that avoid inbreeding and also equalize founder representation to minimize the loss of genetic diversity from the captive population. This is done with the assistance of two software programs associated with SPARKS: DEMOG (by J. Ballou) for demographic analyses; and GENES (by R. Lacy) for genetic analyses.

In the past, the SSP Masterplan process and associated breeding recommendations were based upon inbreeding coefficients and the founder importance coefficient (FIC) which served to equalize relative founder contributions as well as minimize inbreeding. More recently, management has been based on mean kinship value (MK). Mean kinship is an average measure of how related an animal is to all other individuals in the population. Not only does MK allow the equalization of relative founder contributions, but MK also allows the linkage of rare and common genomes to be avoided, making future equalization of founder contributions possible. Animals with a low MK share fewer genes with the rest of the population and are therefore more valuable as potential breeders than those animals with a high MK (e.g., a founder that has never bred has a mean kinship of 0 and therefore is genetically highly valuable). An animal with a low MK should not be bred with an animal with a high MK; otherwise, rare genes would be permanently linked with common genes and could not be increased in frequency without simultaneously increasing common lineages.

Another value which is also used in management is the kinship value (KV), which is a weighted mean kinship which considers the reproductive potential of the animal's relatives in the population. Animals with only old relatives that are unlikely to produce any more offspring would be considered more valuable to breed (and have a lower KV) than animals with many relatives that are young and may produce many offspring.

When the Management Group considers animals to pair for breeding recommendations, it first turns to the list of animals ranked by either mean kinship or kinship value. Animals at the top of the list are given high priority for breeding; animals near the bottom are unlikely to receive a breeding recommendation. Another major consideration is the location of each animal. The Management Group must consider which institutions have requested a breeding recommendation, which institutions would like to keep particular animals, and which institutions want to transfer an animal in or out of their institution. Distance from each other is also a consideration (it is better to transfer an animal from Chicago to Detroit rather than Chicago to Phoenix, both in terms of distance and climatic adjustment). It is best to minimize transfers when possible, as they are costly and involve some disturbance and risk for the animal.

Each potential breeding recommendation must also be separately checked for the inbreeding coefficient of any resulting offspring. For instance, the top ranked male and the top ranked female may look like a good breeding pair; however, they may be brother and sister and would produce cubs with a high inbreeding coefficient.

The number of breeding recommendations that will be made are dependent upon the carrying capacity of the SSP, which is the total number of spaces available in all of the participating zoos for that particular species. In general, the SSP tries to maintain as much genetic diversity as possible, but because of space limitations generally targets 90% of genetic diversity of the wild population for 100-200 years as a reasonable goal. The more animals in the captive population, the more probable this goal can be achieved. But the "Zoo Ark" has limited spaces and there are just too many passengers that need to be brought aboard. For that reason, there is often a compromise between what can be accomplished given the available spaces and what is optimal given the genetic and demographic variables of the species under consideration.

Once the above information is available the management group must identify which animals are to breed, when their breeding is to be scheduled, and at what facility. These institution-by-institution recommendations are then approved and the process begins. Cooperation among the various zoos involved is critically important if the program is to succeed. Construction of new exhibits, incompatibility of selected mates, unanticipated medical problems and other unplanned for contingencies are the rule rather than the exception. Breeding and transfer recommendations may be revised as individuals are born, die or otherwise enter or leave the SSP managed population, as each of these events affects the genetic value of each remaining animal in the SSP. However, through patience, compromise and creative rescheduling none of these problems are insurmountable. The SSP remains a viable alternative to the extinction process.

Together, zoos in many regions of the world are organizing well-planned and tightly coordinated programs for captive management to meet the above goals. In North America these programs are called SSPs; in Europe they have the acronym of EEP for European Endangered Species Programmes, and in Australasia they are the ASMP, or Australasian Species Management Program. China, Japan, India, Thailand, Malaysia and Indonesia have equivalent programs and more are being developed worldwide. The next challenge is to integrate all of these regional programs into comprehensive global masterplans for each endangered species, similar to the goals of the IUCN's Heritage Species Programs. These programs were originally named Global Animal Survival Plans, but have since been renamed Global Conservation Strategies (GCSs) and are under the aegis of the IUCN/SSC Conservation Breeding Specialist Group (see below).

Tiger Species Survival Plan


The Tiger SSP provides a good example of how North American zoos are working together to protect an endangered species. Small pockets of tigers remain in forest patches spread from India across China to the Russian Far East and south to Indonesia. Three of the recognized eight subspecies are now extinct; a fourth is near extinction. To provide viable captive populations for the recovery or reenforcement of wild populations, the 1988 Tiger SSP Masterplan recommended the management of 175 Siberian (P.t. altaica), 175 Sumatran (P.t. sumatrae), 75-80 Indochinese (P.t. corbetti) and 75-80 Bengal (P.t. tigris) tigers in the 500-525 "manageable" tiger spaces available in AZA SSP institutions.

At the 1992 AZA Tiger SSP Mid-Year Meeting at Front Royal, it was decided that it was not possible to retain 90% of the genetic diversity for 100 years for each of the four designated taxa given the steadily decreasing tiger space in North America. The AZA Tiger SSP recognized that cooperation with other regional programs would be necessary, as well as incorporating new founders and genome resource banking (GRB) to augment the existing managed captive populations. With this combination of management strategies, a smaller population of about 100 animals could be managed for each of the four subspecies. At that time, this seemed a realistic goal given the report of the AZA Felid TAG, which suggested that future space needs for other potential felid SSPs would compete with existing tiger space commitments.

At the 1992 IUCN/SSC CBSG Tiger Global Animal Survival Plan (now GCS) Meeting in Edinburgh, Scotland, representatives from regional tiger programs (North American SSP, European EEP and JMSP, Indian IESBP, and Southeast Asian SEAZA) recommended that the North American Tiger SSP be responsible for jointly coordinating programs for P.t. altaica (with Europe and Japan), P.t. corbetti (with range countries only) and P.t. sumatrae (with Europe, Australasia and Indonesia). The Bengal subspecies P.t. tigris will be managed in Europe and India only. The South China tiger P.t. amoyensis will be managed in China and possibly Japan.

These recommendations were ratified at the 1992 Annual Tiger SSP meeting in Toronto. In effect, only three tiger subspecies will be managed in future SSP programs.

While all three subspecies programs are pursuing additional founder stock, the Siberian tiger program is close to maturity. The target population has been achieved and reproduction is being strictly controlled to stay within the available space. One problem confronting the Tiger SSP is the large number of surplus animals in this population.

The Sumatran tiger program is developing; the captive population has now filled all available space. As natural attrition of surplus Siberian and generic tiger populations continues, space made available will be dedicated to Sumatran and Indochinese tigers. A recent site evaluation of Sumatran tigers in zoos in Java, Indonesia was conducted in February 1994 (see Tiger SSP Issues). A program for the Indochinese tiger subspecies is underway, but with only ten animals is far from maturity.

Current Population Status

The Siberian tiger population has reached target levels and is essentially stable, while the Sumatran population is expanding to reach target. A few institutions have chosen to switch from the Siberian to the Sumatran subspecies, but not enough to warrant concern over competition for space between these programs. Not represented in the table is the large number of generic tigers currently held in North American zoos (estimated at 190 in July 1992). The spaces occupied by these animals will be utilized for the

The surplus, or non-breeding, population in the Tiger SSP numbers 47 animals. These animals are considered surplus due to age, sterility or genetic overrepresentation in the population. The success of the tiger masterplan is contingent on surplus animals being removed in a timely fashion to make room for animals resulting from recommended breedings and to accommodate the addition of new founder stock. Ideally, these animals would be lost through attrition by natural causes (old age), but improvements in health care and management have greatly lengthened an average tiger's life span.

Both the Siberian and Sumatran tiger populations have added new founders in recent years as they approach the goal of 26 effective founders for each program. Two Siberian tiger founders were added to the AZA Tiger SSP in 1991 and another two in 1993, all young wild-caught tigers whose mother was likely killed by poachers.

Example Data Table

Siberian (through 30 June 1994)

2 Years Ago1 Year AgoCurrent Year
# of Participants (# of MOPs) 85 88 90
Captive Population 79.85.0 85.78.0 82.73.3
# SSP animals managed 119 124 111
# SSP animals not required to meet goals 45 39 47
# animals in non-participant collections but desirable to SSP 0 0 0
Total # of births in SSP program (w/stillborns) 21 9 12
# surviving to 90 days 15 8 8
# of desired births 21 9 12
# of undesired births 0 0 0
# of deaths of SSP animals 18 11 10
# of transfers recommended 14 24 31
# of transfers completed 12 14 23
# of imports 0 2 0
# of exports 0 0 1
# founders with represented descendants 38 39 40

Demographic Trends

The Siberian tiger population is being managed for zero population growth at about 160 animals, and has been nearly stable for the past ten years. In the future, this population will be slowly reduced to about 100 animals. Population demographic analyses for Siberian tigers indicates that they have a generation time of 7.3 years (number of years from birth to the time that the first cub is born), sex ratios at birth are equal, and the litter size averages 2.4 cubs. Mortality prior to reproductive age (4 years) is close to 40%. The total number of founders represented is 40.

Given the current life history characteristics of Siberian tigers, 12 animals must be born each year to maintain the SSP population (assuming neonatal mortality = 36%). This means that five litters must be produced per year (based on 2.4 offspring/litter). Since only about 65% of attempted pairings succeed, this means 8-10 pairings per year need to be scheduled by the Tiger SSP. This number serves to guide breeding recommendations to be made in the institution-by-institution analyses. The ultimate number of offspring to be produced by any individual tiger will depend upon a balance between the degree of founder representation of the animals and its family size.

The Sumatran population is being managed for zero population growth due to space limitations. This population will be managed like the Siberian population and will be slowly increased to about 100 animals. Demographic parameters for this population are essentially the same as those reported for the Siberian population above.

Population Genetics

"Gene drop" analyses conducted on the Siberian population in June 1994 revealed that 95% of the genetic diversity present in the original founders of the population had thus far been retained (up from 91.6% in 1982). Founder genome equivalents are at 11.367 (5.920 in 1982), and founder representation in the population continues to approach target levels. The mean inbreeding coefficient of the managed population has continually decreased, from 0.108 in 1982 to 0.034 in 1994, while the average mean kinship in 1994 was 0.045.

Genetic analyses of the Sumatran population as of June 1994 revealed that 90% of the genetic diversity present in the original founders has been retained. Thirteen founder equivalents (17 actual founders) were represented in the population. The mean inbreeding coefficient of the Sumatran population as of June 1994 was 0.062 while the average mean kinship was 0.095.

Recruitment of new founder stock for both programs is a high priority. Animals are continually being sought from other regional programs through direction from the IUCN/SSC CBSG Tiger GCS.

Tiger SSP Issues

Sumatran Tiger Genetics: During the course of the AZA Tiger SSP project "In Situ Development of the Indonesian Regional Sumatran Tiger Masterplan" conducted in February 1994, evidence was uncovered that suggests that a number of studbook registered Sumatran tigers in the Indonesian Zoological Parks Association (PKBSI) have been hybridized with unknown tiger subspecies. Furthermore, a majority of the founders to the PKBSI program could not be verified as wild-caught. Multiple levels of unreported inbreeding were also documented. Taken together these discoveries could potentially have a profound impact on the AZA Sumatran Tiger SSP program, which led to the recommendation that a breeding moratorium for Sumatran tigers be implemented immediately across all institutions in the AZA Tiger SSP and that no further imports of Sumatran tigers should be initiated or completed until the Sumatran tiger verification issue can be

Space: The AZA Felid TAG conducted in 1992 a carnivore cage space [one cage space equals one pair of animals] survey of 148 AZA accredited institutions. Tigers account for the largest proportions of large felid cage space (currently 163 spaces representing a maximum capacity of 474 animals), with an anticipated increase to 172 (max. of 506).

The major problem facing the AZA Tiger SSP is the large number of surplus Siberian tigers occupying space in North American zoos. Fully 30% of the animals in the current population are surplus to the breeding program. These animals are impacting the ability of the Tiger SSP to meet its genetic and demographic program goals. Communications from several participating institutions indicate an unwillingness or inability to comply with breeding recommendations until surplus tigers are removed, and several others have requested guidance on how to deal with their surplus problem.

Excess production is not the problem; reproduction among surplus tigers has ceased and over half of the 47 surplus animals in the present population are now over 12 years of age. Many of these surplus animals can reasonably be expected to persist for a decade or more. Thus, the problem is due to the inability of institutions to remove animals that no longer contribute to the program, particularly animals of advanced age. The issue of management euthanasia has arisen repeatedly and has been regularly put aside.

A new recommendation from the 1992 AZA Felid TAG Meeting gives some direction on this issue (Policy of the Culling of Surplus Animals, see Chapter 7, Policies). This recommendation was also endorsed by the AZA Tiger SSP at the 1992 Annual AZA Meeting in Toronto. Beyond this statement, there is no organizational direction from the AZA/WCMC or the AZA Board of Directors for institutions facing this difficult decision. The current AZA policy on euthanasia does not address the removal of surplus SSP animals in order to meet the genetic and demographic goals of these programs.

Subspecies: Another concern revolves around the issue of species definition. The biological validity of the five extant races, or "subspecies," of tigers (Siberian, Sumatran, Indochinese, Bengal, and South China) is not established. The molecular, electrophoretic and phylogenetic evidence presented at the 1986 International Tiger Symposium indicated no clear nor compelling need to separate the tiger species into its presently referred to subspecies. This present day division of Panthera tigris revolves around geopolitical positions rather than biological distinctions (see below).

Advances in Management and Research

Tiger Reproduction (IVF): The first live tiger births from in vitro fertilization/embryo transfer, the result of collaborative efforts of the National, Minnesota and Omaha Zoos, occurred at the Omaha Zoo in April 1990. Through the continued efforts of these institutions, the first live tiger birth from artificial insemination occurred at the Omaha Zoo in November 1991 to parents under-represented in the SSP population. This work is all part of the larger goal to develop the technology for genetic resource (sperm, ova, embryos) banking in this species, which will permit development of interactive management strategies within and between both wild and captive tiger populations. Further attempts in assisted reproductive techniques for tigers were made in 1993 and 1994 at Omaha Zoo but with no success.

Tiger Contraception: L. Munson is involved in research on the effects of megestrol and melengestrol acetate contraceptive implants on mammary and endometrial tissues in non-domestic cats. Her report indicated that felids exposed to melengestrol or megestrol had more severe grades of endometrial hyperplasia than control felids. Due to these findings, the AZA Tiger SSP recommended a set of contraceptive methods that are situation dependent (see Chapter 5, Reproduction).

Genome Resource Banking: The AZA Tiger SSP recommended that genome resource banking be considered as a new strategy to augment the preservation of genetic diversity in captive tiger populations. A comprehensive draft document Genome Resource Banking Action Plan for Tigers by D. Wildt et al. is under review by the IUCN/SSC Captive Breeding Specialist Group. Nine "probable" Sumatran tiger founders were banked by a team led by A. Byers during the recent Sumatran tiger conservation project in February 1994.

Tiger Taxon "Subspecies": A new molecular DNA study of all tiger subspecies has been initiated by S. O'Brien, National Cancer Institute. This study is scheduled to be mostly accomplished by fall 1994 [to be published in the conference proceedings from Tigers 2000, due out in the fall of 1998]. Tissue biopsies from approximately 40 Sumatran tigers in the PKBSI program, four of which are verifiable founders, was exported from Indonesia and delivered to O'Brien's lab. Funding for the collection of these tissue biopsies in Indonesia came from the AZA Ralston Purina Big Cat Survival Fund and the Minnesota Zoo.

Tiger Global Conservation Strategy (GCS)

Tiger GASP coverThe IUCN/SSC CBSG Tiger Global Conservation Strategy (GCS) is a strategy for the management of tigers at the international level that links in situ and ex situ conservation activities for the recovery and/or long-term maintenance of captive and wild populations. This document represents the first version of a Global Conservation Strategy (GCS) [originally termed Global Animal Survival Plan, and since renamed) for tigers under the aegis of the Captive Breeding Specialist Group (CBSG), Species Survival Commission of the World Conservation Union (IUCN). It is the result of an international tiger workshop conducted 9-10 July 1992 at the Edinburgh Zoo, Scotland, and was revised at the Annual Meeting of the IUCN/SSC CBSG in Antwerp, Belgium on 3 September 1993.

The purpose of the Tiger GCS is to initiate a global captive conservation program for tigers by providing a strategic framework for the most efficient application, and most economic allocation, of zoo resources for the species. In part, it accomplishes its global responsibilities by:

  • Adopting global goals for tigers, in part by considering recommendations from Conservation Assessment Management Plans and Global Captive Action Plans;
  • Dividing responsibility for achieving minimum target population sizes of tigers among the regional programs;
  • Arranging interactions for tiger or genome exchanges among regional management programs to achieve global and regional goals;
  • Developing a global masterplan to guide the propagation and management of tigers at the international level.

A primary focus of the Tiger GCS is on captive management programs that can serve as genetic and demographic reservoirs to support the survival and/or the recovery of wild populations in the future. Another focus is to identify where and how the world captive community can assist with the transfer of captive management information and technology to wild populations, and to develop priorities for limited financial support from the captive community for in situ conservation by linking ex situ and in situ programs.

The Tiger GCS recommends a global minimal target population size of 250 tigers in captivity for each of the five taxa, and suggests how this can be most satisfactorily distributed among various regional programs. Minimum target population sizes are defined as the smallest population size to meet the genetic and demographic objectives; actual population sizes in different regions may be much larger. This population size of 250 tigers for each taxon will be sufficient to preserve 90% of the genetic diversity of each population for 100 years.

As a first priority, captive management programs for each subspecies should be developed in its country of origin. For maximum security against risks, extension of the captive management program to at least one additional region outside the range country is also recommended for each taxon.

  • Initiate significant captive breeding programs for P. tigris sumatrae, P.t. amoyensis, P.t. corbetti, and P.t.tigris outside the range states for these taxa.
  • Suggest the non-range-state responsibilities for these programs be divided by: North America developing a corbetti program; Europe, a tigris program; and eventually a region outside China, possibly Japan, an amoyensis program.
  • Assist in the development and integration of captive breeding programs in the region of origin.

The Tiger GCS recognizes the potential value of genome resource banking and assisted reproductive techniques for enhancing populations of tigers both in captivity and in the wild. It also recognizes the value of results obtained in Population and Habitat Viability Analysis (PHVA) Workshops, which focus primarily on the distribution, status and threats to wild populations, and culminates in the drafting of an action plan. To date, only the Sumatran tiger has been the subject of a PHVA workshop; the other tiger taxa are in need of similar workshops.

Tiger GCS Committee Members

Global Coordinator Ronald Tilson (Minnesota Zoo)
Regional Coordinators: European EEP Tiger Coordinator Sarah Christie (London Zoo)
North American SSP Tiger Coordinator Ronald Tilson (Minnesota Zoo)
Japanese SSCJ Tiger Coordinator Masayoshi Gondo (Kobe Oji Zoo)
Australasian ASMP Tiger Coordinator David Pepper-Edwards (Taronga Zoo)
Indian IESBP Tiger Coordinator S.K. Patnaik (Nandankanan Zoological Park)
Indonesian PKBSI Tiger Coordinator Jansen Manansang (Taman Safari Indonesia)
Southeast Asian SEAZA Tiger Coord. On advice of SEAZA
Chinese CAZGA Tiger Coordinator Xiang Peilon (Chongquing Zoo)
Russian Tiger Coordinator On advice of Moscow Zoo
International Studbook Keeper Peter Muller (Leipzig Zoo)
IUCN/SSC CBSG Executive Office Ulysses Seal (IUCN/SSC CBSG)
IUCN/SSC Cat Specialist Group Peter Jackson (IUCN/SSC CSG)

The Tiger GCS has been recognized as a strategic document to manage captive tigers on an international level by the Australasian ASMP, Indonesian PKBSI, Southeast Asian SEAZA, Indian IESBP, Japanese SSCJ, North American AZA, and European EEP. The Tiger GCS will then be submitted to the IUCN/SSC for recognition; the Tiger GCS Committee will then proceed with its implementation globally.

Linking in situ and ex situ Tiger Conservation

Beyond the concerns for the captive population there is a need to model the status of wild tiger populations, the effects of current removal rates from the wild populations and the contribution these tigers can make to captive populations. All populations, however large or small, are at some risk of extinction. The smaller the population, the more likely it will occur. Countering the trend toward even smaller populations of wild tigers requires that conservationists develop interactive strategies for managing fragmented wild populations and for using captive populations for backup and support.

Zoos are responding in several ways. One is by growing larger, by building new facilities, and by developing offsite breeding centers for endangered species. These actions increase the overall captive carrying capacity, and will thus provide more space for additional SSPs. Zoos also are working hard at expanding their captive carrying capacity by developing assisted reproductive technology, specifically aimed at embryo transfer, artificial insemination and gamete freezing. If successful, even moderately, zoos could increase the effective size of a few hundred living animals to thousands of potential animals by cryopreservation of genetic material. These technologies should not be viewed as a resolution to the extinction process, but as additional alternatives for the long-term conservation of species.

Another way zoos can contribute is to assist with the transfer of knowledge and technology that empowers range countries to develop and manage their own programs. The development of captive breeding programs in regions of origin and encouraging these range states to concentrate on their endemic subspecies is one of the highest priorities of the Tiger Global Conservation Strategy (GCS). This is the most powerful contribution the Tiger SSP can make to the conservation of tigers globally. It is also logical, because it is our skill, knowledge, and technology that is most needed in tiger range countries, and these are our most available assets.

With this perspective in mind, the Tiger GCS Committee identified some major components of a comprehensive tiger conservation plan. These in situ and ex situ projects are listed below:

Molecular DNA Study. The most promising method to distinguish tiger subspecies is through molecular DNA technology. As of today, this technology is only in its infancy, is relatively expensive, and has limited availability. Because the subspecies issue is so critical to determining evolutionary significant units (significant to the management of populations), the Tiger GCS supports continued research to clarify taxonomic distinctness of extant taxa, including: a) distinction between P.t. tigris and P.t. corbetti; b) distinction between P.t. sumatrae and mainland forms; c) distinction between P.t. altaica and southern forms; and d) estimation of genetic diversity among fragmented wild tiger populations. This molecular DNA study is currently underway and supported by S. O'Brien, National Cancer Institute, Frederick, MD.

Population and Habitat Viability Analyses. Because we know so little about wild tigers, the single most frustrating aspect in tiger conservation is trying to estimate their numbers in the wild and the degree of fragmentation they suffer. Another obstacle is not knowing what the threats are to these populations, particularly the extent of poaching. As of today, the PHVA process is the single most effective method to derive reasonable estimates of these variables. Together these estimates permit an assessment of the viability of each population. The Tiger GCS strongly supports assisting conservation agencies in tiger range countries to conduct Population and Habitat Viability Analyses (PHVAs) for their extant tigers. This process has already commenced with Sumatran tigers in Sumatra, Indonesia (conducted in November 1992). The next highest priorities are for Siberian (in the Russian Far East), South China (in China), and Indochinese tigers (in Malaysia, Thailand, Laos, and Vietnam). Although tigers may be found in North Korea, Cambodia and Myanmar, we do not believe they have the appropriate conservation infrastructure in place to benefit by a PHVA.

A Case Study— Sumatran Tiger PHVA

The first Sumatran Tiger Population and Habitat Viability Analysis Workshop was held 22-26 November 1992 at Padang, West Sumatra, Indonesia. The declining status of all tigers, and the Sumatran tiger in particular, is due to habitat loss and fragmentation, resulting in populations too small for long term survival in the majority of the national parks and game reserves established to protect them. Poaching for medicinal and economic purposes further exacerbates the small, fragmented population dilemma. Other factors contributing to the overall decline in tiger numbers include decreasing prey availability and increasing tiger control as a result of livestock depredation and human-tiger interactions.

Results of the workshop indicated that there were about 400 Sumatran tigers living in five national parks and two game reserves, with another 100 tigers living in unprotected areas which will soon be lost to agriculture. Poaching is ongoing and uncontrolled, and forest disturbance has further fragmented these populations. The largest population of about 110 tigers is estimated to be in Gunung Leuser National Park; the remaining populations are about one-half this size or smaller. These small populations are extremely vulnerable to poaching or removing problem animals, and because of their isolation and fragmentation, will need interactive management strategies for long-term viability. This led to the development of an Indonesian Sumatran Tiger Action Plan which outlines short-term and long-term goals to address these problems (Tilson et al. 1994).

Geographic Information System (GIS). To prepare for a PHVA and to assist conservation agencies in tiger range countries to develop an accurate and standardized mapping system, a map-linked database using Atlas Geographic Information System (GIS) software needs to be developed. Satellite imagery overlays of vegetation cover of tiger habitat (from World Conservation Monitoring Center-WCMC) can be matched up with range country land-use and forest status maps and geographical maps. This database gives a comprehensive spatial analysis of tiger habitat which allows distinctions such as lowland rain forest from montane forest from mangrove forest, protected forest from non-protected forest, and various land use categories which will affect tiger distribution in the future. This process put the H (for Habitat) into the PHVA acronym, and is a valuable analytical process, an indispensable training tool, and permits interactive development of management scenarios at the workshop.

Regional Captive Management Programs. Before populations of wild tigers fall to crisis levels, which precludes developing management strategies except in panic, captive populations of tigers need to be secured while there are still sufficient numbers of wild tigers left. These captive populations will provide a genetic and demographic reserve to reestablish or revitalize wild populations when the need and opportunity arises. The first stage in developing a regional captive management program for tigers in range countries is to establish a regional studbook, train a tiger management group in concepts of tiger management, husbandry and health, plan the breeding facility, and initiate the regional tiger masterplan. This process allows range countries to develop their own management programs for their endemic subspecies as recommended by the Tiger GCS. Tiger subspecies with high priority in need of program development include the Indochinese tiger in Malaysia, Thailand, Laos and Vietnam, and the South China tiger in China.

This second-stage development of regional captive management programs provides hands-on training sessions at each zoo that focuses on animal health procedures for medical treatment, immobilizations, immunizations, evaluations, health maintenance and diets, and the use of ARKS record keeping software program. This is culminated with a masterplan meeting where the masterplan with institution-by-institution breeding recommendations are drafted, translated into range country language, and distributed to participating zoos. At the same time, biological material (usually sperm, blood, and tissue) are collected and cryopreserved as part of the IUCN/SSC CBSG Tiger Genome Resource Banking Action Plan (see below).

A Case Study—Indonesian Program for the Sumatran Tiger

The first Regional Captive Breeding Workshop for Sumatran tigers was held in November 1992 at Taman Safari Indonesia. Nine of 11 Indonesian zoos sent 39 staff to the workshop. Javan zoos included Taman Safari Indonesia, Ragunan Zoo (Jakarta), Yogyakarta Zoo, Solo Zoo, Semarang Zoo, Surabaya Zoo, Bandung Zoo, and from West Sumatra, the Jambi Zoo. The products of this Sumatran Tiger Workshop include:

  1. Preventive Medical Procedures: Veterinary staff attended tiger immobilization training sessions focusing on proper animal health procedures for medical treatment, immobilizations, immunizations, evaluations, and health maintenance. Animal physical examinations (four males, one female) included permanent tattooing of each animal with a temporary studbook number and placement of a transponder as a backup identification system.
  2. Tiger Facility: A tiger captive breeding facility was designed and constructed at Taman Safari Indonesia (see below);
  3. Husbandry: Animal management staff received training in proper animal husbandry procedures for maintaining captive tigers on a day-to-day basis;
  4. Reproductive Evaluation Procedures: Training was also conducted regarding semen collection, evaluation and storage techniques necessary for the establishment of a genome resource banking program. Semen was collected and frozen from three adult male founders for permanent storage in Indonesia.
  5. Husbandry Manual: The Tiger Husbandry Manual was evaluated for its use in Indonesia and translated into Bahasa Indonesia;
  6. Studbook: A Regional Sumatran Tiger Studbook was established and an Indonesian Tiger Studbook Keeper was trained in the use of SPARKS (see below);
  7. Masterplan: An Indonesian Captive Breeding Masterplan for Sumatran tigers was drafted; and a PKBSI Tiger Management Committee was formed.

The Indonesian Sumatran Tiger Regional Captive Breeding Program will serve as the heart of the global Sumatran tiger population by preserving sufficient genetic diversity to provide animals for reinforcement of world captive and wild populations as recommended in the Tiger GCS. The establishment of this Regional Program will also serve as a model for other regional endangered species captive breeding programs in Asia. By acting now while Sumatran tigers are still present in sizeable numbers in the wild, we have the potential and the resources to act effectively to prevent Sumatran tigers from extinction.

Regional Captive Breeding Facilities. With few exceptions, tiger facilities in Asian zoos are too overcrowded, reproduction occurs but neonatal mortality is high, diets are poorly balanced, and medical immobilizations, immunizations and examinations are rarely performed because of lack of drugs, equipment and experience. The net result is that wild tigers frequently die as soon as they are placed in such zoos, and if they do live, they seldom raise viable young. This is a regrettable waste of a valuable resource. These issues can be remedied by constructing a modern captive breeding facility in range countries as part of a regional masterplan. As a model, a breeding facility was designed and constructed for Sumatran tigers at Taman Safari Indonesia in November 1992 (see below). Five similar facilities need to be constructed for Indochinese tigers (in Malaysia, Thailand, Laos, and Vietnam) and South China tigers (in China).

Indonesian Tiger Breeding Facility

A captive breeding facility for Sumatran tigers was constructed at Taman Safari Indonesia and was dedicated on 17 November 1992. It was funded by Taman Safari Indonesia and 18 North American zoos through the Tiger SSP. This facility measures 15m x 21m and is large enough to maintain four or more adult breeding pairs of tigers. The facility includes two separate mixing and breeding areas, two separate maternity dens with outside runs, holding space with outside runs for tiger progeny, and a service kitchen. Currently, four male and one female Sumatran tigers (all wild-caught founders) are housed in the facility.

Regional Tiger Studbooks. All species management programs in captivity are predicated on the creation of a studbook, which establishes the identity and origin of each individual animal, and tracks each animal from birth to death. Thus, it will be necessary to establish Regional Studbooks for each regional captive tiger program. Costs include computer hardware, training in studbook software programs (SPARKS), and studbook publication and distribution. The Indonesian Sumatran Tiger Studbook will be completed in January 1994; others needed are the Indochinese (four countries) and South China Tiger Studbooks.

Genome Resource Bank. A successful cryobiology program for tigers will have a significant impact on conserving genetic diversity. A resource of frozen tiger semen will be used interactively with living tiger populations to periodically infuse genetic material from captive or wild populations and to instill captive populations with preserved genes from previous generations. The options cryobiology brings to long-term tiger conservation strategies are limited only by our imagination, but only as long as this program proceeds in concert with protection of wild populations. The Tiger GCS strongly recommends that a systematic Genome Resource Bank (GRB) for tigers be initiated, which includes the collection, storage, use, exchange, and further research of genetic material from founders and selected free ranging and captive individuals. Elements of this GRB are being developed for Sumatran tigers, which will serve as the model for all Asian tigers (see Genome Resource Banking Action Plan). The Sumatran tiger in Indonesia needs to be completed, the Indochinese tiger needs to be collectively banked from wild-caught tigers in Malaysia, Thailand, Laos, and Vietnam, as well as the South China tiger from wild-caught tigers in Chinese zoos.

Indonesian Studbook for the Sumatran Tiger

Information regarding all Sumatran tigers in Indonesian zoos was compiled and verified for entry into the Indonesian Regional Sumatran Tiger Studbook using the Single Population and Analysis Record Keeping System (SPARKS). Temporary studbook numbers were assigned to those animals which could not be linked to the International Tiger Studbook. At the completion of the workshop, information regarding 76 Sumatran tigers (38 male, 38 female) comprised the Regional Studbook. Of the 42 Sumatran tigers (25.17) currently living in Indonesian zoos, 11 (7.4) are wild-caught founders (only three of which have produced offspring). These preliminary analyses were used by workshop participants to evaluate tentative management strategies for the Regional Captive Breeding Program.

Dr. Ligaya Tumbelaka, Taman Safari Indonesia, was appointed as the Indonesian Regional Studbook Keeper. She will work directly with animal management staff at the Indonesian zoos as well as the Regional Sumatran Tiger Coordinator to rectify remaining inconsistencies in the database. She is also responsible for submitting an annual report to the International Tiger Studbook, kept by P. Muller, Leipzig Zoo.

Tiger International Newsletter. Accurate information is vital to making good decisions. In the case of the tiger, situations can change rapidly and this information needs to be widely circulated to maintain a coherent conservation program for all tigers. For example, the Siberian tiger population for decades has been considered safe; with the recent breakup of the Soviet Union, chaos has reigned. In recent months poaching has proliferated and the wild Siberian tiger is nearly gone. This is just one example; we need to be able to respond to other such crises. This can only be achieved by having a centralized database of field research, public policy, and anecdotal reports on trends affecting tigers throughout Asia. To this end, the Tiger GCS recommends publishing and distributing three issues per year of Tiger Beat, the international newsletter of the Tiger GCS to all tiger constituents. This includes field researchers, managers of tiger protected areas in Asia, key forestry and conservation agency staff in range countries, appropriate NGOs, politicians and the world zoo community. The Minnesota Zoo has published this newsletter since 1987 and distributes it to a membership of over 500 individuals globally.

Tiger Husbandry Manual. In Asian zoos, medical and management records for tigers are poorly kept, if at all, and no captive management plan exists for any zoo population except for Indonesia. This is directly attributable to lack of knowledge that is easily remedied by the production, publication and translation into the language of the range countries of a tiger husbandry manual for use in tiger regional captive management programs. Indonesian and Thai versions are already complete.

Overview of Zoo-Based Conservation Programs

1982: First Species Survival Plan initiated by the AAZPA was for the Siberian tiger by Ulysses Seal.

1986: International Symposium, World Conservation Strategies for Tigers, coordinated by the IUCN/SSC CBSG, Cat Specialist Group and Minnesota Zoo.

1987: Tigers of the World: The Biology, Biopolitics, Management, and Conservation of an Endangered Species, edited by R. Tilson and U. Seal, published.

1988: AAZPA Tiger SSP Masterplan recommended that SSP programs be developed in North America for: 175-200 Siberian (P. tigris altaica), 175 Sumatran (P. tigris sumatrae) and 75-80 each of Bengal (P. tigris tigris) and Indochinese (P. tigris corbetti). South China (P. tigris amoyensis) tiger program to be based at Chinese zoos.

1990: First live tiger births through in vitro fertilization and embryo transfer occurred at the Henry Doorly Zoo in collaboration with the National and Minnesota Zoos.

1991: EEP Sumatran Tiger Program established.

1991: First live tiger birth through artificial insemination occurred at the Henry Doorly Zoo with the National and Minnesota Zoos.

1992: EEP Amur Tiger Program established.

1992: First meeting of the AAZPA Felid Taxon Advisory Group, during which the first Felid Action Plan was developed, classifying P. tigris amoyensis and P. tigris sumatrae as critical, and recommending that PVAs and captive breeding programs be developed. Other tiger subspecies: PVA required, captive programs desirable.

1992: First IUCN/SSC CBSG Tiger Global Animal Survival Plan, linking in situ and ex situ conservation programs for tigers on a global level, developed at the Edinburgh Zoo with participation from the AAZPA, EEP and Indian Zoo Authority.

1992: First Population and Habitat Viability Analysis (PHVA) conducted for tigers (Sumatran subspecies) at Padang, West Sumatra in collaboration with the Indonesian Department of Forest Protection and Nature Conservation (PHPA).

1992: First Regional Captive Management Program for tigers in Asia (Sumatran subspecies) by the Indonesian Zoological Parks Association (PKBSI).

1993: First IUCN/SSC CBSG Genome Resource Bank (GRB) for Tigers review draft by D. Wildt et al. developed in Antwerp, Belgium.

1994: Indonesian Sumatran Tiger GRB established at Taman Safari Indonesia among CBSG, PKBSI and PHPA.

1995: South China Tiger Studbook and Masterplan of the Chinese Association of Zoological Gardens established.

1995: Indochinese Tiger Masterplan for Thailand of the Zoological Parks Organization of Thailand established.


Tilson, R.L. Cats in zoos. In GREAT CATS: MAJESTIC CREATURES OF THE WORLD. J. Seidensticker and S. Lumpkin, eds, Weldon Owen Publishing: Sydney. Pp. 214-219, 1991.

Tilson, R.L.; Foose, T.J.; Princee, F.; Traylor-Holzer, K. TIGER GLOBAL ANIMAL SURVIVAL PLAN. IUCN/ SSC Captive Breeding Specialist Group: Apple Valley, MN, 1993.

Tilson, R.L.; Soemarna, K.; Ramono, W.; Lusli, S.; Traylor-Holzer, K.; Seal, U. SUMATRAN TIGER POPULATION AND HABITAT VIABILITY ANALYSIS REPORT. Indonesian Forest Protection and Nature Conservation and IUCN/SSC Captive Breeding Specialist Group, Apple Valley, MN, 1994.

Tilson, R.L.; Traylor-Holzer, K.; Brady, G.; Manansang, J. SUMATRAN TIGER REGIONAL CAPTIVE BREEDING PROGRAM REPORT. Indonesian Zoological Parks Association and IUCN/SSC Captive Breeding Specialist Group, Apple Valley, MN (in press).

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