Zoos
Zoos have existed in some form since at least 2500 bce in Egypt and Mesopotamia, where records indicate that giraffes, bears, dolphins, and other animals were kept by aristocrats. These private collections of wild and exotic animals for exhibition, called menageries, were precursors to modern zoos; a menagerie is now a general term for any unusual and varied collection of things. The oldest zoo still operating is Austriaâs Vienna Zoo (Tiergarten Schönbrunn), which began as a menagerie in 1752 in the gardens and park of the Schönbrunn Palace, the Habsburg rulersâ summer residence. The zoo was opened to the public in 1779.[1] [2]
Franceâs king at this time, Louis XVI (1774â92), also had a royal menagerie at his residence, the Palace of Versailles, outside of Paris. When the king was ousted and the palace abandoned during the French Revolution, the royal animals were transferred to the Paris Jardin des Plantes (Garden of Plants), which opened its menagerie to the public in 1794.[45]
These menageries and early zoos were a perfect reflection of the ongoing Enlightenment intellectual movement, during which the spirit of curiosity enveloped Europe and scholars sought to better to understand the natural world through science, reason, and observation. Studying animals was a key aspect of the Enlightenment.[46]
The word zoo evolved as a popular shortened form of âzoological garden,â and was first used by the founders of the London Zoological Society in 1826. They modeled their society after the Jardin des Plantes in Paris.[42] The London society opened its own âzoological gardenâ (later called the London Zoo) two years later, in 1828.[43]
This zoological connection between Paris and London made history again in 1865, when the Jardin des Plantes gave the London zoo a small male African elephant named Jumbo, who grew into the largest elephant in the world and whose name became a worldwide symbol and synonym for anything huge. The London Zoo received another animal destined for fame in 1914, when it inherited an American black bear cub called âWinnie,â named after its ownerâs home in Winnipeg, Canada. The cub became a favorite of zoo visitors, inspiring English writer A. A. Milneâs creation of Winnie-the-Pooh.[44] [53]
By the mid-19th century, zoos were opening around the world. Largely modeled after the London Zoo, these facilities were intended for âgenteel amusement and edification,â according to Emma Marris, environmental writer and Institute Fellow at the UCLA Institute of the Environment and Sustainability. As such, reptile houses, aviaries, and insectaries (a place for keeping and raising insects) were soon added to zoos, to move them beyond the mere spectacle of showcasing big scary animals.[40]
Carl Hagenbeck (1844-1913), an internationally famous German animal dealer and trainer, introduced the prototype of the modern open-air zoo at his Animal Park in Hamburg in 1907. There animals were exhibited not in cages but in artificial environments more akin to their natural habitat. Hagenbeck also instituted more humane methods of caring for and training zoo animals and deemphasized the beating of the animals. This change prompted the shift in zoo narrative from entertainment to the protection of animals.[40]
Controversy has long shadowed exhibitions of live animals, from displays of âexoticâ humans in exhibits offensively called âfreak showsâ to zoos ignorant on how to properly care for their animals. For example, a gorilla from the French Congo named Madame Ningo, the first gorilla in North America and the first to arrive and be exhibited in the United States (1911), lived at the Bronx Zoo in New York Cityâshe was fed hot dinners with cooked meat from a nearby restaurant, though gorillas are herbivores (plant eaters). The gorilla refused to eat and died in two weeks. The zoo director was furious with the animal, saying she âdeserved to be [dead], for its obstinacy.â[3] [4]
In the contemporary debate over zoos, both sides tend to focus on animal welfareâwhether zoos protect animals or imprison them. So, should zoos exist? Explore the debate below.
Pros and Cons at a Glance
| PROS | CONS |
|---|---|
| Pro 1: Zoos educate the public about animals and conservation efforts. Read More. | Con 1: Zoos donât educate the public enough to justify keeping animals captive. Read More. |
| Pro 2: Zoos produce helpful scientific research. Read More. | Con 2: Zoos are detrimental to the animalsâ physical health. Read More. |
| Pro 3: Zoos save species from extinction and other dangers. Read More. | Con 3: Zoo confinement is psychologically harmful to animals. Read More. |
Pro Arguments
(Go to Con Arguments)Pro 1: Zoos educate the public about animals and conservation efforts.
As of September 2025, there were 254 accredited zoos, aquariums, and related facilities in 13 countries. At last count, in 2024, the zoos attracted over 209 million visitors annually, which is 54 percent more than the approximately 135.3 million spectators of games played in 2024 by the MLB (71.3 million), NBA (22.3 million), NFL (18.6 million), and NHL (23.0 million) combined.[5] [6] [7] [8] [9] [10]
According to a study of 26 zoos worldwide published in Conservation Biology, visitors to zoos increased their knowledge of biodiversity and efforts to protect it. [11]
Robin Ganzert, president and CEO of American Humane, said,
Zoos provide people, especially impressionable children, with the opportunity to see these remarkable animals up close. People wonât protect what they donât love, and they canât love what they donât know. No matter how closely programs like Planet Earth depict animals, nothing will match the bond of seeing them in real life. Just look at a childâs eyes at the zoo when he or she encounters a tiger or similarly majestic animal.[12]
Furthermore, zoos have incredible reach via social media. Pygmy hippos Moo Deng (at Thailandâs Khao Kheow Open Zoo) and Mars (Tanganyika Wildlife Park in Goddard, Kansas), king penguin Pesto (Sea Life Melbourne), giant panda Fu Bao (China Conservation and Research Center for the Giant Panda), Asian elephant Kirby (Houston Zoo), and orangutan Rocky (Indianpoilis zoo) are just a few of the viral zoo stars that capture the publicâs heart and imagination, leading to increased knowledge and support for the species. [47] [48] [49] [50] [51] [52] [13]
Pro 2: Zoos produce helpful scientific research.
In 2024, the Association of Zoos and Aquariums reported member institutions spent $30.3 million on research over 1,839 projects and 435 peer-reviewed publications that studied 652 species and subspecies (148 of which were endangered). [14]
Because so many diseases can be transmitted from animals to humans, such as Ebola, hantavirus, and bird flu, zoos frequently conduct disease surveillance research in wildlife populations and their own captive populations that can have a direct impact on human health. For example, the veterinary staff at the Bronx Zoo alerted health officials to the presence of West Nile virus. [15]
Zoos and zoo research are used in other ways, too, such as promoting legislation like the Sustainable Shark Fisheries and Trade Act, helping engineers build a robot to move like a sidewinder snake (so the robots can move uphill and on slippery and sandy slopes), and encouraging with workshops and programs more minority students to enter STEM careers . [37] [38] [39]
Pro 3: Zoos save species from extinction and other dangers.
Corroboree frogs, eastern bongos, regent honeyeaters, Panamanian golden frogs, Bellinger River snapping turtles, golden lion tamarins, and Amur leopards, among others, have been saved from extinction by zoos.[16]
Zoos are also working to save polar bears, tigers, and wild African elephants from habitat loss, apes and rhinos from poachers, dolphins and other whales from hunters, and bees and butterflies from population declines, among many other efforts.[17] [18] [19] [20]
According to researchers, 23 percent of birds and 47 percent of small mammals (weighing less than about 2.2 pounds) are being harmed by climate change. By keeping populations of animals and conducting wild re-population, zoos can help preserve species in danger from climate change. There were only 9 California condors in the wild in 1985. However, by 2016 a joint conservation effort between the San Diego and Los Angeles zoos with other organizations had increased the population of condors in the wild to 276 and in captivity to 170. [21] [22] [23]
Przewalskiâs horses, the last wild horses, were declared extinct in the wild in the 1960s when about 12 lived in zoos. By 2018, breeding programs at zoos had increased the number to 2,400 horses, and 800 were reintroduced to the wild. [24] [25]
Con Arguments
(Go to Pro Arguments)Con 1: Zoos donât educate the public enough to justify keeping animals captive.
A review published in Animal Studies Repository concluded that âthere is no compelling or even particularly suggestive evidence for the claim that zoos and aquariums promote attitude change, education, and interest in conservation in visitors.â Even a study widely cited to justify the argument that zoos educate the public stated that âthere was no overall statistically significant change in understanding [of ecological concepts] seen,â because visitors know a lot about ecology before going to the zoo.[26] [27]
TV shows such as Planet Earth bring wild animals into living rooms, allowing people to see the animals in their natural habitats without causing harm to animals such as the endangered snow leopard. As British comedian Romesh Ranganathan stated,
It still slightly surprises me that anybody thinks that we should have zoos at all. The animals always look miserable in captivity.âŠThe idea that kids only get excited about things they can see in the flesh is ridiculous. My kids are obsessed with dinosaurs that no longer exist, and Skylanders, which have never existed.[28]
Con 2: Zoos are detrimental to the animalsâ physical health.
A study of 35 species of carnivores, including brown bears, cheetahs, and lions, found that zoo enclosures were too small for the animals to carry out their normal routines, which led to problems such as pacing and increased infant deaths. Polar bears, for example, had an infant mortality rate of 65 percent due to small enclosures.[29]
About 70 percent of adult male gorillas in North America have heart disease, the leading cause of death among gorillas in captivity, although the condition is almost completely absent in the wild. Other great apes have similar health problems in captivity.[4]
Captive elephants (for exhibition) live about half as long as wild elephantsâ16.9 years versus 35.8 years (for African elephants)âand about half as long as working elephantsâ18.9 years versus 41.7 years (for Asian elephants). Of 77 elephants in 13 zoos, 71 were overweight and spent 83 percent of their time indoors, contributing to early death.[30]
Con 3: Zoo confinement is psychologically harmful to animals.
Animal behaviorists often see zoo animals suffering from behavioral problems not seen in the wild, such as clinical depression in clouded leopards and gibbons, obsessive-compulsive disorder (OCD) in brown bears, and anxiety in giraffes. The animals experience these issues due to smaller enclosures, changes in diet and activities, and the introduction of things not seen in the wild, such as medical exams and people with cameras. The Toledo Zoo in Ohio ran a psychiatric program in which a gorilla with premenstrual depression was prescribed Prozac. To ease them into new habitats, an agitated tiger was given Valium, and anxious zebras and wildebeests were given Haldol.[31] [32] [33]
A study of captive chimpanzees found that âabnormal behavior is endemic in the populationâ and includes such actions as eating feces, twitching, rocking back and forth, plucking hair, pacing, vomiting, and self-mutilation. The study concluded that the cause of such behavior could be mental health issues.[34]
According to one study, 24 percent of captive orcas (killer whales) had âmajorâ to âextremeâ tooth wear, and 60 percent had tooth fractures as a result of stress-induced teeth grinding. The 2013 documentary Blackfish highlighted Tilikum, a male orca captured at age two off the coast of Iceland in 1983 and kept at SeaWorld Orlando in Florida until his death in 2017. Confined for nearly his whole life, Tilikum grew increasingly aggressive, eventually killing three people, including two trainers. The deaths led to many ethical discussions about captive animals and even spurred legislation concerning marine mammals in captivity. The breeding of captive orcas was subsequently outlawed in certain states, zoos, and theme parks.[35] [36]
Slideshow: Animals in zoos
Assessment quiz
After reading the above debate, take our assessment quiz to test your knowledge of this issue. Good luck!
1-minute survey
After reading this debate, take our quick survey to see how this information affected your opinion of this topic. We appreciate your feedback.
Discussion questions
- Should zoos exist? If you believe they should, consider whether they should remain the same or change. If you believe they should not, consider how else to accomplish zooâs conservation efforts. Explain your answers.
- Extend the debate to other artificial animal habitats, such as safari parks and animal sanctuaries. Should they exist? Why or why not?
- What other conservation efforts are important to saving wildlife? Explain your answer.
- Consider how you felt about the issue before reading this article. After reading the pros and cons on this topic, has your thinking changed? If so, how? List two to three ways. If your thoughts have not changed, list two to three ways your better understanding of the other side of the issue now helps you better argue your position.
- Push for the position and policies you support by writing U.S. senators and representatives.
Sources
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- Jan Flemr, âLong Way Home as Przewalskiâs Horses Fly to Mongoliaâ (July 19, 2018), phys.org
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- Romesh Ranganathan, âZoos Are Prisons for AnimalsâNo One Needs to See a Depressed Penguin in the Fleshâ (March 13, 2017, theguardian.com
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