May 05, 2016

By Jack Grisham
Vice President, Animal Collections

The Saint Louis Zoo's Red Rocks area is "baby central" in the spring, with recent births of multiple hoofed animals—two Spekes gazelle, two addax calves, a lowland nyala calf, a Grevy's zebra foal and a takin calf. All are endangered or threatened in the wild. Elsewhere at the Zoo, three critically endangered Edwards's Pheasant, a king penguin chick and a Grey crowned crane have hatched—all were hatched in early January. The Zoo's New Year's arrivals were capped off by the birth of a black and white colobus monkey.

Addax calf and mom Addax calf and mom

All of these births were the results of breeding recommendations by the Association of Zoos and Aquariums (AZA) Species Survival Plans®. Each zoo typically has space for only a limited number of animals of each species, so maintaining healthy populations requires that zoos accredited by AZA manage animals in their care cooperatively. Zoos coordinate breeding efforts and transfer animals within AZA to maximize available spaces, all while striving to maintain genetic diversity. So baby booms are not haphazard affairs. They are carefully planned with a strong focus on saving species. Everything we do in zoos is tied to wild populations – from the zoo's fence to the field.

Baby Grevy's zebra and mom Baby Grevy's zebra and mom

That is more the case now than in past. An infinite number of species are going extinct around the world—many more are increasingly threatened. These population collapses have been sudden, dramatic and unexpected. So zoos are now playing a critical role in fighting extinction through managed collaborative breeding programs that can assist with this crisis by injecting healthy new genes into small and isolated populations. Sadly, many fragmented wildlife populations will require human intervention to maintain viable and genetically diverse populations.

Managed breeding in zoos also provides scientists an opportunity to observe and research animal reproduction, behavior and nutrition —fully understanding a species biology can be vital in assisting conservation efforts in the wild.

Takin calf and mom Takin calf and mom

Of course, public education is another goal of zoo breeding. Surveys show that when visitors see and experience animals in zoos in their natural multi-generational family groups, they better understand and appreciate the importance of saving wild things in wild places.

Then there is the hope that zoo-born animals can be reintroduced to the wild. We can point to several examples of species that were born and raised in zoos and then returned to the wild, thus saving those species from extinction. Here are only a few of the stories:

  • Birds on the islands in the Mariana Archipelago in the Pacific were almost decimated by a brown tree snake introduced to these islands during World War II; eight of the 11 native bird species of Guam vanished. The rapid demise of these birds prompted the Saint Louis Zoo to join forces with other zoos and government agencies to form the Pacific Bird Conservation Program. Zoos developed breeding protocols for endangered species and with their partners, moved birds from snake-invested islands to snake-free islands with the goal of saving birds from extinction.
  • In 2015, the Saint Louis Zoo's WildCare Institute Saharan Wildlife Recovery Center, a founding member of the Sahara Conservation Fund, began planning the reintroduction of the scimitar-horned oryx—extinct in the wild due to overhunting, drought and habitat loss. The very last oryx was killed in Chad in 1989 and now some 27 years later the antelope's return has taken on national significance and has the full cooperation of the Chadian government. On March 21, twenty-five scimitar horned oryx that were born and raised in human care were safely released into their natural habitat in Chad as part of an initiative that involved several partners.
  • Then there is the tiny snail that almost 30 years after going extinct in the wild, was returned home to the Papehue Valley on the Tahiti island of French Polynesia. These rare snails, raised in zoos across the world, were all descendants of snails collected in Tahiti in 1984, when three scientists realized that some of the species of Partula snails in that area had vanished. They were victims of a predator snail introduced by humans. In 1988, the Saint Louis Zoo became a leader in creating a breeding plan to save these snails, and in 2015 the Zoo contributed 140 individual snails to the shipment of 243 that went to London Zoo. There they received a thorough health screening before being placed on a flight back home to Tahiti.
  • The story of the Ozark hellbender, brought back from near extinction by the Saint Louis Zoo and its partners, is equally inspiring. Since 2012, the WildCare Institute's Ron Goellner Center for Hellbender Conservation has worked to augment Ozark river populations of the endangered Ozark hellbender. Working with the Missouri Department of Conservation, the Center has moved 2,115 Zoo-born hellbenders into Missouri rivers.
King penguins and chick King penguins and chick

In the end, the goal of most endangered species breeding programs is to establish genetically healthy populations that are large enough to be demographically stable, that is representing a range of ages and genders similar to what you would find in wild populations. This means maintaining a healthy age structure, ensuring reproduction is reliably successful, protecting the population against diseases and preserving the gene pool to avoid the problems of inbreeding.

Saving species is a complex endeavor. To be successful, it requires careful planning and sufficient space to breed and raise enough animals for collaborative zoo programs. Preventing species extinction requires a delicate balance of resources and science, and we celebrate each time a creature is born.
Animals Always!

  Sichuan takin calf exploring at Saint Louis Zoo
Sichuan takin calf exploring at Saint Louis Zoo