So often the news isn’t good. Stories of mishandling and disease, of unsuccessful pairings, serve to remind us of the one true thing about zoos: they house living things, each with complex and varied needs. Zoos have come a long way since they first rose to prominence in Europe during the nineteenth century, serving as weekend strolling parks for the middle class. Back then, very little was known about animal care or habits, so almost no births occurred in captivity—when animals died, new ones were captured in the wild and brought in to replace them. By the 1930s, as attitudes toward animals revised slightly, the design of zoos was refocused with greater priority on the animals’ requirements, natural barriers and green spaces replacing concrete and metal pens. Better surroundings, as well as more humane handling and nutritional techniques, made for healthier animals, and ones that were more likely to breed. And what could be better? Nothing attracted paying visitors like baby animals, and zoos in the ’50s and ’60s rushed to provide them, often inbreeding—breeding closely related animals—and overbreeding in the process, with little regard for future generations. In the late ’70s, scientists at Washington, D.C.’s National Zoo had begun to discover the harmful effects of the breeding programs at the time. Researchers noticed increased birth defects, mortality rates, and susceptibility to disease in the captive-bred animals, a tendency that increased from one generation to the next. This is the raison d’etre of the Species Survival Plan, instituted in 1981 to try to minimize inbreeding and, in the long term, to stave off species extinction. Administered by the American Zoo and Aquarium Association (AZA) in Silver Spring, Md., and offering detailed plans for the survival of the carefully selected group of species it covers, it has become one of the primary ways that zoos and aquariums manage their species breeding programs. When a zoo holds an SSP species (there are about 150 of them), it agrees to follow the official recommendations of the SSP, cooperating with the AZA as well as other participating facilities to provide animals with proper care. One of the SSP’s defining characteristics is the “studbook” it keeps for each species, which is a digital system that provides zoos with the information they need to maintain a diverse gene pool. The studbook is a record of a species’ entire managed population, including births, deaths, transfers, and lineage. Animals are assigned a permanent studbook number that follows them to whatever zoos they may be moved to. Before mating occurs, a computer simulates the process using the studbook number to see if the prospective pairing will maintain, increase, or decrease that species’s genetic diversity. Each SSP is also assigned a species coordinator who manages the animal’s day-to-day activities, with the help of elected committees, which assist the coordinator with the larger conservation concerns for a particular species, including research, education, and, in some cases, reintroduction into their natural habitat. Sometimes, too, an animal’s survival plan has meant curbing or ceasing its breeding. Zoos avoid breeding animals that are genetically overrepresented in the population, which involves providing reliable contraceptive methods so that the animals can continue living in their usual social groups. According to Ana Bowie of the Denver Zoo, participant in the SSP since its inception, the Denver Zoo has decreased its breeding programs since the ’80s to comply with SSP breeding recommendations. “To prevent offspring, more animals have been put on contraception,” she says. Honeymoon in Denver This doesn’t mean all the animals at the Denver Zoo have stopped breeding. Recently, two Amur tigers (commonly known as Siberian tigers and found in the Amur-Ussuri region of Siberia) were relocated there. These animals are severely endangered, totaling no more than 200 in the wild. The SSP for tigers, which was the very first developed by the AZA, manages more than 150 Amur tigers in 90 zoos. Because the cost of housing tigers is so high, there is added emphasis placed on the ones selected to be compatible. Bowie says that Tiaga, a three-year-old male from the Minnesota Zoo, and Katarina, an 11-year-old female from the John Ball Zoo in Michigan, appear compliant. “They have already been observed breeding,” she says. Zoos often participate in several SSP pairings at once. Bowie says the Denver Zoo is currently attempting to breed black rhinoceroses, red pandas, snow leopards, and an okapi. After a successful conception and birth, there’s no guarantee that the offspring will stay with the zoo. Says Bowie, “We cannot say how long any specific SSP animal will remain at the zoo.” The two tigers were brought to Denver in November 2002 and allowed on display in February of this year. The gestation time for tigers is approximately 110 days, Bowie says. “Keepers detect specific behavioral changes such as rolling and vocalizations that indicate the female is in estrus.” The Denver Zoo also recently relocated two of its lowland gorillas to Busch Gardens Tampa Bay as part of the SSP, and will be welcoming five gorillas from the Los Angeles Zoo to be housed temporarily while the Los Angeles Zoo builds a new gorilla habitat. Delivery in D.C. If you went to the Smithsonian’s National Zoo in Washington, D.C., on any given Saturday in 2002, you probably noticed the large gathering outside the elephant exhibit waiting for Kandula, son of Kandhi and Calvin, to step outside. When he did, he usually stayed beneath his mother, looking healthy if a bit unhinged, bobbing and weaving for cover. In a year that saw the birth of a male western lowland gorilla, a Sumatran tiger, and a Masai giraffe, the elephantine addition to the zoo’s family arrived in November 2001: Kandula, a 325-pound Asian elephant bull. It is only the fifth artificial insemination elephant birth in the world, and the National Zoo’s second baby elephant since it began its breeding program in 1990. “He brings in thousands of visitors and provides a wonderful educational opportunity,” says Marie Galloway, elephant manager at the National Zoo. Elephants have been one of the most difficult species to breed in captivity. According to the AZA, only 132 elephants have been born in North America, the majority of those in the past 40 years, thanks to research, better handling techniques, and, at least in part, necessity. In hopes of putting a stop to the ivory trade, the Convention on the International Trade in Endangered Species in 1976 outlawed international exchange of wild elephants, limiting U.S. zoos to the small elephant population already in North America. The AZA created the SSP for Asian elephants in 1985, allowing zoos to share and better manage captive elephants. But while the frequency of elephant births in American zoos has increased, nearly half of the delivered calves die before their first birthday. Add to this a serious shortage of breeding-age elephants (there are only nine Asian elephants among the SSP’s 81 member zoos who are between 14 and 25, the best age range for elephants to reproduce, according to the AZA), and the outlook is pretty unfavorable for captive breeding. “Our program has dedicated itself to creating a natural multi-generational related family unit of elephant,” says Galloway. “The breeding program is more farsighted than it has been in the past. We’re trying to look beyond just a mother and calf.” Galloway points to many difficulties in breeding elephants, including “identifying the precise time of ovulation, getting bulls to cooperate the day they are needed, and, since semen cannot yet be frozen successfully, getting it to National Zoo the same day—Kandula has an absentee father: He resides at the Calgary Zoo.” National Zoo director Dr. Lucy Spelman has set out an ambitious 10-year plan for a massive zoo renovation, which includes the Asia Trail with its new elephant facility that can accommodate bulls like Kandula, who are naturally more aggressive and stay away from the matriarchal herds, as well as up to six females. It is landscaped like a South Asian forest, with wide trails nearly a mile long that will not only allow visitors to view the elephants in different places, but will also provide vital exercise for the pachyderms. By late 2006, according to Galloway, Kandula’s current home, a run-down facility built during the Great Depression, will be replaced by this new one. Cats in the Desert When a zoo first enlists to be an SSP facility, it tries to create a sustainable captive population by acquiring a large number of unrelated “founder” animals. This is just what the Living Desert Zoo and Gardens in Palm Desert, Calif., did with the sand cat, an animal that is about the size of a house cat with pale, sandy-gray fur and large ears. Found in the North African and Arabian Peninsula, they are threatened by the fur trade. “The founding population is so small,” says Terrie Correll, CEO of Living Desert and AZA’s Species Survival Plan coordinator for sand cats. “But our breeding program has been very successful.” Now, especially, might be a problematic time for a zoo to embark upon a sand cat breeding program. Because they come from an area of the world with an uncertain political climate—North Africa and the Arabian peninsula—it’s difficult to easily acquire a diverse pool of rehabilitated animals for breeding. Whereas, with an animal like the cougar, found widely in the United States, this wouldn’t present a problem. The 100-acre Living Desert has been participating in the sand cat SSP for about three years now, though they’ve had sand cats since 1987. There are 28 sand cats in nine AZA institutions in North America. The Living Desert, which specializes in animals from arid habitats and is the largest holder of sand cats in North America, helped the AZA assemble the SSP breeding recommendations for this species. “It definitely has changed the way we manage sand cats for breeding,” Correll says. “The memorandum of understanding signed by AZA institutions adds a little bit of teeth to your program, helping to encourage the participation of other facilities. Once the breeding is successful, we often place the animals in other AZA institutions, and this requires a little marketing on our end. That’s another one of the functions of the SSP. “We also work with the Felid Taxon Advisory Group, developing a web site and exploring the plush market, with stuffed animals that have a conservation message, getting the word out that other zoos can include sand cats in their conservation programs.” Other SSP animals at the Living Desert include fennec foxes, cheetahs, Grevy’s zebras, and several different types of antelopes and gazelles. With some of these, the Living Desert, along with other organizations and zoos, sponsors field research; with others it tries to promote conservation tactics. Breeding an animal like the sand cat calls for different requirements than, say, breeding an Asian elephant. Essentially, it’s much easier. But one thing they have in common is that the intention is to use the animal to promote a message of conservation in the zoo. Reintroduction is the end goal of an SSP only when it is the sole way to ensure a healthy and viable wild population, as with black-footed ferrets, red wolves, and the much-publicized California condors. The great majority of SSPs help by promoting fundraising programs and research, and by providing education programs through classroom visits and school field trips. More than 70 million people visit zoos each year in the United States, providing them with a captive audience to teach about endangered species, conservation, and habitat loss. It has been estimated that in the next 200 years more than 800 species will require maintenance in captivity to survive, including all 160 primate species—great and lesser apes, monkeys, lemurs, and their relatives. This also includes 60 out of 72 species of cats (lions, tigers, etc.); and pretty much all of the animals you see displayed in the African section of zoos: giraffes, rhinoceroses, tapirs, and elephants. In the future, zoos will more and more be presented with a bittersweet task: displaying animals that no longer exist in the wild.