Zoos: Saviors of Threatened Species or Creators of Unnatural Ones?

Candice Gaukel Andrews by Candice Gaukel Andrews | December 17th, 2012 | 6 Comments
topic: Eco Travel, Green Living

Lion Under Tree

A new species of lion has recently been discovered, announced the National Geographic Society a few weeks ago. Were the animals caught by camera trap or spotted by a tracker in the remote regions of Africa? No. They were found — in all places — in an Ethiopian zoo. It’s questionable whether any other representatives of this species are alive in the wild today.

All over the world, the struggle to keep endangered species from going extinct is often played out in zoos or in captive breeding centers. The last known Tasmanian tiger lived out its life in a zoo before it died in 1936, giant pandas are being bred in Chinese reserves and whooping cranes are being raised at the Patuxent Wildlife Research Center in Maryland.

Living in zoos or in other places of captivity, however, changes wild animals — sometimes to the point where behaviorally they little resemble their wild counterparts. But is keeping an altered, threatened wild species from going extinct better than losing it altogether?

Lions alive

Whooping Crane

Whooping cranes have avoided extinction with the help of captive breeding programs. ©John T. Andrews

In a study recently published in the European Journal of Wildlife Research, scientists, led by the Max Planck Institute for Evolutionary Anthropology in Germany and the University of York in the United Kingdom, reported that they had identified a previously unknown population of genetically distinct lions in an Addis Ababa zoo. By comparing DNA samples from 15 of these zoo lions to six populations of wild lions, the researchers discovered that the gene sequence of the zoo lions was unique.

The Addis Ababa lions have dark manes and small bodies, unlike other African lions. The animals belonged to Ethiopia’s deceased emperor, Haile Selassie, who established the zoo in 1948. However, the lions’ origins are unknown. It’s postulated that seven founder lions — five males and two females — came from southwestern Ethiopia. It may be that their striking, dark manes proved too alluring to hunters and that is why they are no longer known to exist there.

If there are no more members of this species left in the wild, it won’t be the first lion population to survive only in zoos. Two significant lion populations, the North African Barbary lions and the South African Cape lions, can be found in captivity but have become extinct in the wild.

The Addis Ababa zoo is currently constructing a new facility to house the lions, modeled on their natural environment. The zoo hopes to breed the lions to keep the population alive.

A captive crowd

Some say with extinction rates rising and habitats being destroyed around the globe, zoos are biodiversity’s last best hope. Currently, zoos worldwide are trying to breed about 160 endangered species.

Critics of these efforts, however, state that the idea of a zoo is detrimental to the cause of conservation. They believe that wild animals should not be kept in confinement and that saving a species is doomed to fail under these circumstances, since many animals lose their interest in mating once they are captured. In fact, 83 percent of species being bred in North American zoos are not meeting the targets set for maintaining their genetic diversity, according to the Association of Zoos and Aquariums. For example, fewer than 20 percent of cheetahs in North American zoos have been able to reproduce. At the Smithsonian’s National Zoo in Washington, D.C., the captive population of 281 cheetahs gives birth to only 15 cubs, on average, a year — exactly half of what their keepers estimate is necessary to maintain their numbers.


Elephants roam constantly in the wild. In captivity, however, they must stand still for long periods of time. ©Dave Luck

Such disappointing success rates have led some field conservationists to question whether zoos should be in the breeding business at all. In a closed population, such as in zoos, a high level of genetic diversity is the priority in order to maintain a species’ adaptability and to prevent inbreeding. A kind of reverse natural selection results, with animals that normally would have a low rate of success in the wild often succeeding only because of the rareness of their genes. Many say they would prefer to see the monies spent on breeding programs redirected to preserving wild habitats and species.

In addition, some animals are distinctly unsuited for life in a zoo, such as elephants. In the wild, elephants roam constantly, covering a lot of ground on a daily basis. In captivity, they have no choice but to stand still for long periods of time, putting severe strain on their legs and feet, which leads to chronic injuries.

Yet in their native environments, elephants are heavily poached for ivory, leather and meat. And many elephants in captivity were rescued from circuses, saved from natural disasters or removed from the wild due to abandonment. Would it have been better if these animals had been euthanized or left to die rather than placed in captivity?

Do you think that zoos play a vital part in keeping threatened species from going extinct, even though the results of captivity or of a captive breeding program may not reflect the development of that same animal in the wild?

Happy trails,


Feature photo: Extinct in the wild, some lion species survive only in zoos. ©Eric Rock



  1. It’s not a choice. Zoos are essential, period.

    Marc d'Entremont | December 18th, 2012 | Comment Permalink
  2. That’s a good topic Candice but general enough for both points of view to be considered true.
    Animals are being poached to near extinction across Africa & Asia & are in desperate need of protection.
    But then Przewalski horses, ancestors of modern day horses depicted in prehistoric cave art at Lascaux in France (l5,000BC), was hunted & collected to extinction in the wild by 1969.

    Zoo specimens were becoming increasingly feeble due to in-breeding and dependent on zoo keepers. Then in 1977 Dutch couple Jan and Inge Bouman formed the Foundation for the Preservation and Protection of the Przewalski Horse. They obtained specimens from zoos all around the world & mixed the blood stock & bred 2 generations with minimal human contact. They were released back into the wilds of Mongolia in the 80’s & have regained their wild nature & independent herds breed naturally.

    So zoos have been part of the problem but they can be part of the solution – if you can find a place where people don’t kill released animals.

    There’s more info about the Przewalski Horse project on my website.

    Peter Lynch | December 19th, 2012 | Comment Permalink
  3. “At the Smithsonian’s National Zoo in Washington, D.C., the captive population of 281 cheetahs gives birth to only 15 cubs, on average, a year…” er……
    I think that is the total number of cheetahs in North American zoos. The National Zoo has 6 cheetahs. See: http://nationalzoo.si.edu/animals/africansavanna/meetcheetahs.cfm

    As to your question…. I’m agnostic. Since conservation and the recovery of species should be directed by scientific principles and the results measured, it doesn’t really matter what I “think.” What matters is if the zoo programs are effective at achieving their mission. That mission is wildlife conservation, not captive breeding, which is merely a means to an end. Some zoo programs are effective in this regard. Others are not. Either way, everyone involved in conservation has an obligation to continually measure the results and adjust their methods.

    Greg | December 20th, 2012 | Comment Permalink
  4. Thank you for this article, and raising the question. Species in the wild form the fabric of interconnectedness, of our natural reality. It is a loss when we loose a species in the wild, which happens way too often. Zoos have often funded conservation in the field, and can provide a possibility to repopulate a genetically diverse species. Work with zoo breeding, for example, has helped save the golden lion tamarin, although it is still threatened. Zoos also provide a place to inspire children and adults. A world without zoos would be a world few of us would like to see.

    Douglas B. Trent | December 27th, 2012 | Comment Permalink
  5. Thank you for the question and thanks to those responding. I agree with them.

    A subordinate question to yours — Who makes the decision about what species to bring back from the edge of extinction? Such action is not inexpensive. Are there criteria for consideration? Should there be? Is it a fundamental instinct to tackle a task because of its notoriety and loss to society? What would have been the harm if the Condor had been allowed go the way of the passenger pigeon and was no longer seen riding the thermals? Vultures and eagles do the same. (I was an advocate and active participant in the Condor captive breeding program – I am simply using it as an example.)

    Glenn Carpenter | January 7th, 2013 | Comment Permalink
  6. There are many good arguments both for and against captive breeding programs. Choosing cheetahs as an example was probably not the best choice, as they have been declining in the wild, both due to human-induced problems, but more importantly, because of some genetic bottle neck that occurred in the past, leaving virtually all of the animals too closely related. In the wild. I’m not talking about once they have been taken into captivity.
    As far as other animals, there are great success stories for animals that would otherwise be extinct today – California condors, Tahitian lories, Arabian oryx, Swinhoe pheasants; the list goes on. These animals have in most cases been able to have been returned to the wild successfully. Zoos with a vision were able to accomplish this and are continuing to do so. I’m not saying all zoos, obviously.

    TerryAnn Willingham, RVT | January 10th, 2013 | Comment Permalink

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