Animal Welfare and Rights: V. Zoos and Zoological Parks

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Editor: Stephen G. Post
Date: 2004
Encyclopedia of Bioethics
From: Encyclopedia of Bioethics(Vol. 1. 3rd ed.)
Publisher: Gale
Document Type: Topic overview
Pages: 5
Content Level: (Level 4)

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Wild animals have been displayed in captivity for millennia (Luoma). The first known large collections were assembled in Egypt around 2500 B.C.E. Early rulers displayed their exotic menageries, captured during campaigns or expeditions, for personal amusement and as symbols of wealth and political power. Romans later maintained menageries for bloody public spectacles, sending elephants, lions, bears, and other wildlife into battle in arenas throughout Europe. Urban zoos appeared in sixteenth-century Europe and North Africa; visitors ogled strange creatures captured on colonial adventures. In 1828, the first zoo dedicated to the scientific study of captive wildlife opened in London, and in 1889, the U.S. Congress established the National Zoo for the purposePage 209  |  Top of Article of breeding native wildlife. As zoos continued to evolve in the twentieth century, they developed a broad mission that included research, conservation, education, and entertainment.

Zoos, aquariums, safari parks, and wildlife theme parks are popular worldwide. Approximately 400 professionally managed zoos exist in the world, in addition to thousands of roadside menageries and petting zoos (Chiszar et al.). Annual zoo attendance in the United States alone exceeds one hundred million (Nelson). According to studies conducted in the United States and Canada, one-third of the public has visited a zoo within the last twelve months, and 98 percent of adults have visited a zoo in their lifetimes (Nelson).

Despite their broad popularity, zoos are increasingly criticized on ethical grounds. As the public has grown more sensitive to animal-welfare and conservation issues, animal advocates have begun to question whether or not the benefits of zoos justify the incarceration of live, and often rare, wild animals. (Although the term zoo may refer to a broad range of animal facilities, for the purposes of this entry it will refer only to zoos and aquariums that meet at least minimum professional standards. These minimum standards are defined by the American Association for Zoological Parks and Aquariums [AAZPA] in the United States.)

The Ethics of Captivity

Many zoo opponents hold that wild animals should not be kept in captivity for human benefit. Dale Jamieson (1985) argues that animals taken from the wild are deprived of the opportunity to behave naturally. They are removed from their natural habitats, separated from family and social groups, and prevented from performing natural behaviors such as gathering food. Most important, the animals lose the freedom to pursue their own lives. Therefore, even under the best zoo conditions, Jamieson believes there exists a moral presumption against keeping animals in captivity.

Critics also focus on the possibility of physical or psychological suffering caused by captive conditions. Despite improvements in exhibit design, many animals remain confined in dirty, cramped, and isolated cages. Indoor facilities often lack fresh air and natural light, while outdoor enclosures may expose animals to extreme weather conditions to which they are not adapted. Without social or environmental stimulation, captive wildlife may become listless, self-abusive, or develop stereotypical behaviors such as the pacing often observed in big cats (Fox). When elephants or other potentially dangerous animals display aggression, zookeepers may respond with harsh discipline or physical restraints. The capture of animals in the wild, their transportation to zoos, and the handling required for veterinary care are other sources of stress.

Perhaps the most controversial source of potential suffering is the disposition of "surplus" animals. The zoo surplus includes aged adults and excess offspring of breeding programs. Animal activists assert that many surplus animals suffer inhumane treatment when zoos sell them to animal dealers who, in turn, sell them to research laboratories, private collectors, roadside menageries, and hunting parks (Clifton). An equally controversial disposal method is "culling," or mercy killing for management purposes. Critics decry this killing of healthy animals, especially when the surplus results from careless management. Animal advocates stress that zoos have a moral obligation to care for all zoo animals, regardless of their utility for breeding and other zoo goals.

Zoo advocates agree that culling is ethically problematic. However, they contend that responsible zoo directors manage breeding programs to avoid surpluses through contraception and segregation of sexes (Bostock). When contraception fails or a zoo's needs change, the director is expected to follow the AAZPA's code of ethics for distributing surplus animals to other qualified zoos or dealers. Euthanasia is seen as a last, though sometimes unavoidable, resort. To sustain viable captive populations of endangered species, zoo scientists must carefully balance age and sex ratios to maintain genetic diversity. Animals that are old, infertile, or genetically undesirable become surplus because zoos have limited space and financial resources. Zoo proponents defend culling these individuals as a necessary evil. Euthanasia and other disposal methods, proponents claim, allow zoos to conserve populations and species, although some individual animals must be sacrificed.

Animal welfare, according to zoo advocates, remains a high priority (Hutchins and Fascione). While recognizing that inferior enclosures still exist, they applaud the revolution in naturalistic exhibit design. At many zoos, for example, primates have been moved from isolated, tiled cells to family groupings in outdoor facsimiles of their native habitat. Tropical birds have flown from their cages into reproductions of rain forests. In addition, animal behaviorists are studying ways to stimulate animals' physical and mental activity, and veterinarians are investigating how to improve their nutrition and health. Through advances in captive breeding, zoos have also been able to reduce their demand for animals captured in the wild. Zoo advocates point proudly to these improvements, arguing that mortality and morbidity rates at zoos do not support claims that the animals are miserable (Chiszar et al.).

Furthermore, zoo proponents object to claims, such as Jamieson's, that captive animals suffer as humans would from the loss of liberty. Animals, they believe, may be happier in an enclosure free from predation and hungerPage 210  |  Top of Article than they are in the wild. Expecting animals to have the same needs and desires as humans do—an attitude called anthropomorphism—is viewed as a reflection of animal activists' sentimentality and biological ignorance (Robinson).

Justifications of Zoos

Another approach to the zoo debate is to examine the reasons for keeping animals in captivity. If the benefits of zoos are negligible, animal advocates contend, then keeping wildlife captive cannot be justified. However, if significant benefits can be shown, captivity for at least some animals might be defensible.

ENTERTAINMENT. Historically, the predominant function of zoos has been entertainment. Studies of zoo visitors show that most people continue to see these facilities as parklike settings for casual family socializing (Kellert). To zoo opponents, public amusement is a trivial reason for holding animals in confinement (Jamieson). Opponents especially attack circuslike events, such as sea lion shows, that use trained animals to draw large crowds. Similarly, zoos that import animals such as giant pandas to boost attendance and revenues have been condemned. Such events are seen as denigrating the animals by exploiting them as public spectacles.

Although zoo directors vaunt high attendance rates, many de-emphasize entertainment as a zoo goal (Luoma). Baby elephant rides and similar amusements are gradually disappearing as zoos try to develop a more serious image. However, zoo educators claim that entertainment is necessary to keep visitors interested in learning. Also, zoo administrators assert that animal shows, special events, and traveling exhibits are sometimes essential to raise the funds needed to pay for research and other zoo missions (Cohn).

RESEARCH. Few visitors are familiar with the scientific efforts of zoos. Although a handful of zoos sponsor field research, most studies are conducted on site by zoo staff or affiliated researchers. Common topics include animal behavior, nutrition, reproductive biology, genetics, and pathology (Hutchins and Fascione). Animal activists challenge both the quality and usefulness of this research (Jamieson). According to critics, the experimental design of most zoo research lacks scientific rigor, rarely qualifying for publication in peer-reviewed journals. In a nutrition study, for example, a small sample size or the absence of a control group may obscure study results. Some critics also say that much of the research is aimed at improving captive husbandry and exhibit design—unnecessary benefits if wildlife were not confined in the first place. Regardless of any benefits, some animal-rights advocates oppose all animal research. Tom Regan (1983) argues that the utility of research, whether to gain practical information of basic knowledge, is no justification for violating an individual animal's basic rights.

Zoo scientists reject the position that animal research is intrinsically wrong. They emphasize that most zoo research is noninvasive, nonterminal, and aimed at benefiting captive and wild populations (Hutchins). While acknowledging weaknesses in past studies, zoo proponents see a growing commitment to quality research at many institutions. Zoos are hiring research staff, cooperating with university faculties, and investing in major research facilities such as the U.S. National Zoo's 3,000-acre Conservation and Research Center. Much current research employs sophisticated, controversial techniques, such as embryo transfers, in efforts to improve captive breeding success. Although the experimental techniques may harm individual animals, zoo scientists contend that the long-term benefits for species conservation outweigh the costs to individual animals.

CONSERVATION. Animal advocates doubt that zoos can make a significant contribution to conservation (Fox). Although many recognize the biodiversity crisis, critics hold that zoos can do little to resolve the primary cause of extinction: habitat destruction. Nor can zoos protect more than an insignificant portion of the estimated five to thirty million species on the planet. Further, zoo conservation efforts are biased toward the charismatic large mammals preferred by zoo visitors, nearly ignoring disliked organisms such as bats and invertebrates (Kellert). When zoos do have success in maintaining a captive population, critics worry that the animals suffer from inbreeding and loss of natural behavioral characteristics. Are zoo animals and their wild relatives equivalent organisms? Could animals bred in zoos for generations be successfully reintroduced into the wild? If reintroduction is never possible, how long should the species be perpetuated in zoos? Extinction, to some zoo opponents, is more respectful of individual animals than endless confinement.

Yet conservation is viewed by many as the preeminent function of modern zoos. Zoo advocates liken the zoo to a crowded ark, struggling to accommodate as many threatened species as possible. Advocates remind critics that several organisms have already been saved from extinction by zoos, including the European bison and Mongolian wild horses (Tudge). Increasing resources are devoted to captive breeding through programs such as the AAZPA's Species Survival Plans (SSP) (Wiese and Hutchins). SSPs manage rare animal populations at zoos throughout the country, asking zoos to cooperate in breeding plans that promote genetic variability and demographic stability. SSP organizers hope that as suchPage 211  |  Top of Article programs grow, world zoos will eventually be able to protect 500 to 900 endangered species (Luoma).

Zoos are also expanding efforts to reintroduce animals born in captivity to the wild, using some reintroduction projects to study techniques for managing small, isolated populations in the wild and to encourage habitat protection in developing countries. While they agree that zoos cannot directly save the majority of endangered species, zoo advocates proclaim that saving any species keeps options open for the future.

EDUCATION. The educational benefits of zoos are also viewed skeptically by animal advocates. Visitor studies indicate that relatively few people are interested in learning about animals or conservation, and there is little evidence that the zoo experience improves knowledge of biological facts or conservation issues (Kellert; Kellert and Dunlap). Given zoos' poor record of educational effectiveness, critics suggest that films, lectures, books, and nature centers may offer superior learning benefits without the ethical costs of confining wildlife. Most important, critics charge that zoos may be presenting harmful information and values (Sommer). Seeing rare animals in captivity, for example, may give visitors an inaccurate impression of human abilities to combat extinction. In addition, witnessing listless creatures in sterile cages may diminish respect for animals or concern for conservation.

Zoo advocates respond by describing the diversity of education programs and a growing commitment to educational progress (Chiszar et al.). Zoos attempt to teach casual visitors through signs, demonstrations, learning laboratories, and interactive computer technologies. Part of the revolution in exhibit design aims at enhancing learning by immersing visitors in natural environments. To extend their educational impact, zoos are developing curricula for primary and secondary students, holding workshops for teachers, visiting community centers, and organizing public lecture series. Michael Robinson (1989) promotes such changes as part of an educational revolution committed to teaching visitors about the interactions between wild animals, plants, and humans. Zoo proponents believe that, in our urbanized society, the zoo may be the only institution capable of demonstrating these vital links to the public.

Education, in fact, may offer zoos their best hope of effecting long-term, large-scale benefits (Kellert and Dunlap). If zoo educators could demonstrate positive program impacts, they could defuse criticisms and justify program expansion. Zoos should embark on a coordinated program of systematic educational evaluation and implement their findings through innovative programs dedicated to further progress. Given the wide popularity of zoos, it is doubtful that the ethical debate will result in their abolition. If zoos can learn how to teach the public scientific information and humane and conservation values, animal advocates, zoo proponents, and wildlife will all benefit.





Bostok, Stephen. 1993. Zoos and Animal Rights: The Ethics of Keeping Animals. New York: Routledge.

Chiszar, David; Murphy, James B.; and Iliff, Warren. 1990. "For Zoos." Psychological Record 40(1): 3–13.

Clifton, Merritt. 1988. "Chucking Zoo Animals Overboard: How and Why Noah Culls the Ark." Animals Agenda 8(2): 14–22, 53–54.

Cohen, Carl, and Regan, Tom. 2001. The Animal Rights Debate. Lanham, MD: Rowman & Littlefield Publishing.

Cohn, Jeffrey P. 1992. "Decisions at the Zoo." BioScience 42(9): 654–659.

Fox, Michael W. 1990. "The Zoo: A Cruel and Outmoded Institution?" In Inhumane Society: The American Way of Exploiting Animals, pp. 145–155. New York: St. Martin's Press.

Hutchins, Michael. 1988. "On the Design of Zoo Research Programmes." International Zoo Yearbook 27: 9–19.

Hutchins, Michael, and Fascione, Nina. 1991. "Ethical Issues Facing Modern Zoos," In Proceedings—American Association of Zoo Veterinarians, ed. Randall Junge. Wheeling, W. VA: American Association for Zoological Parks and Aquariums.

Jamieson, Dale. 1985. "Against Zoos," In In Defence of Animals, pp. 108–117, ed. Peter Singer. Oxford: Basil Blackwell.

Kellert, Stephen R. 1987. "The Educational Potential of the Zoo and Its Visitor." Philadelphia Zoo Review 3(1): 7–13.

Kellert, Stephen R., and Dunlap, Julie. 1989. Informal Learning at the Zoo: A Study of Attitude and Knowledge Impacts. A report to the Zoological Society of Philadelphia.

Kohn, B., and Monfort S. L. 1997. "Research at Zoos and Aquariums: Regulations and Reality." Journal of Zoo and Wildlife Medicine 28(3): 241–250.

Luoma, Jon R. 1987. A Crowded Ark: The Role of Zoos in Wildlife Conservation. Boston: Houghton Mifflin.

Nelson, Andrew J. 1990. "Going Wild." American Demographics 12(2): 34–37, 50.

Norton, Bryan G.; Hutchins, Michael; Stevens, Elizabeth F. eds. 1996. Ethics on the Ark: Zoos, Animal Welfare and Wildlife Conservation. Washington, D.C.: Smithsonian Institution Press.

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Regan, Tom. 1983. The Case for Animal Rights. Berkeley: University of California Press.

Robinson, Michael. 1989. "Zoos Today and Tomorrow." Anthrozoos 2: 10–14.

Sommer, Robert. 1972. "What Do We Learn at the Zoo?" Natural History 81(7): 26–29, 84–85.

Tudge, Colin. 1991. Last Animals at the Zoo. London: Hutchinson Radius.

Wiese, Robert, and Hutchins, Michael. 1993. "The Role of Captive Breeding and Reintroduction in Wildlife Conservation." In Proceedings of the AAZPA Regional Conferences. Wheeling, WV: American Association for Zoological Parks and Aquariums.

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Source Citation   

Gale Document Number: GALE|CX3402500056