The Value and Ethical Status of Zoos

Abstract

Ethical concerns surrounding the existence of zoos have recently come to the fore. Some argue for the complete phasing-out of zoos, citing concerns about the limitations they impose on animal liberty and dignity, coupled with perceived minimal benefits to both humans and animals. However, these arguments tend to downplay the potential value that zoos offer in terms of human enjoyment, educational opportunities, research initiatives, and conservation efforts. Moreover, they overlook other significant benefits zoos provide such as the positive impact of human-animal interactions and opportunities to appreciate nature’s beauty. Finally, zoo critics often emphasize the negative effects of zoos on animals while neglecting the substantial efforts made by zoos toward animal welfare research and implementation. By accurately recognizing the multifaceted values that zoos can provide and ensuring the highest standards of animal care, a strong case can be made for their continued existence and importance.

1. Introduction

Institutions that place animals in captivity have increasingly come under attack of late, including circuses, aquariums, zoos, research laboratories, factory farms, and, in some cases, animal sanctuaries and domestic households. Critics have argued that holding animals in captivity violates their right to autonomy or dignity, or is harmful to their overall welfare [1, 2, 3, 4, 5, 6]. Such claims have been especially common in regard to highly intelligent mammals such as elephants, polar bears, lions, and primates. Given their needs for intellectual stimulation and freedom of exploration, various ethicists have alleged that such creatures do not belong in captivity [7, 8, 9, 10]. Philosophers have even written legal briefs alleging mistreatment of such mammals in zoos and aquariums [11, 12, 13].

This paper examines the arguments against maintaining captive animals in zoos, especially mammals [14], and responds to them. Some critics allege that zoos fail to provide for animal welfare to a sufficient degree to justify their existence, at least for sentient beings [15]. Others [16, 17, 18]) argue that in depriving animals of liberty and a natural way of life zoos are unable to furnish them a satisfying life. Finally, there are critics who claim that zoos are fundamentally oppressive in unauthentically offering up animals for display for human pleasure [19, 20, 21].

Against these critiques, this paper asserts that such authors exaggerate the harm done by zoos and the degree to which zoos are unable to provide for animal welfare. It looks at the extensive research on and changes made in zoos to provide satisfying lives for zoo creatures by allowing for a great degree of species-specific behavior and minimizing the presence of deleterious stereotypies. In addition, there are several values which, if properly understood, justify the holding of animals in captivity in zoos. Zoo critics often inaccurately minimize the ability of zoos to provide for research, education, and conservation. And the ability of zoos to offer human entertainment, foster human-animal interactions (a good for both parties), and allow for esthetic appreciation of nature is significant. With an accurate assessment of the welfare of animals in zoos, and an appreciation of the diverse values zoos can provide, there is every reason to see zoos as important cultural and conservational institutions that can and should continue to exist.

2. The ethical critique of zoos

Various philosophers have argued that the confinement of animals in zoos, or at least certain mammalian species, cannot be morally justified. Typically such a view is based either upon utilitarian grounds and a concern for animal welfare, or upon animal rights and a concern for animal freedom or dignity [14]. While noting that zoos have much improved in their ability to care for animals and not cause them overt physical or psychological harm, nevertheless many critics assert that it is still problematic to confine animals in zoos due to their being deprived of a fundamental right to liberty or of dignity [22]. It is not enough for zoos to provide for animal welfare (often cached in terms of the freedom from hunger and thirst, discomfort, pain, injury, or disease, fear and distress [23, 24]), nor a satisfying mental state, nor even to have large and naturalistic enclosures; rather zoos must enable the animals in them to enact the same (or very similar) behaviors that they do in the wild. This is something, however, that zoos, by their very nature, are often unable to do.

One of the earliest such critics was Dale Jamieson. Jamieson argued in his essays “Against Zoos” (1985) and “Zoos Revisited” (1995) that zoos involve “taking animals out of their native habitats, transporting them great distances, and keeping them in alien environments in which their liberty is severely restricted” ([17], p. 167). Consequently, zoos deprive animals of the good of behaving in ways natural to them, including the seeking and gathering of food, interacting with members of the same species in complex ways, and developing a social order. There is thus a moral presumption against keeping animals captive in zoos, as it deprives them of their interest in liberty; and such captivity would still be illicit even if zoo animals led overall less painful and more pleasant lives than their wild counterparts. Nor are the overall contributions zoos make to entertainment, education, research, and conservation enough to overcome this moral presumption, and indeed these ends could be accomplished in other ways, such as through films. Zoos, wherein human beings treat animals as “there for our pleasure, to be used for our purposes” ([17], p. 175), ought then to be abolished.

Marc Bekoff and Jessica Pierce argue along similar lines regarding zoo life that “Good welfare is not and can never be good enough … [as] the animals on display suffer from huge losses of freedom” ([16], p. 94). For even if zoos furnish naturalistic and enriched habitats (with varied and unpredictable environments with some capacity for exploration and play), and the animals there do not display any behaviors suggestive of poor physical or mental health, zoos still deprive animals of important freedoms, namely freedom of control and the ability to engage in the full range of behaviors indicative of their species. There are always limits on the behavioral choices available to zoo creatures. Coupled with the fact that visitors often do not learn much about animals at zoos, visiting each exhibit for a short period, nor leave the zoo much more likely to get involved in conservation efforts, zoos should be replaced with more enlightened animal sanctuaries that are either closed to the public or allow very limited access [25].

Tzachi Zamir, while defending the ethical legitimacy of companion and farm animals on the basis of their being able to live qualitatively satisfying lives, argues that placing animals in zoos cannot be similarly justified [18]. Just as it would be unwarranted to confine humans to cages, or to remove human infants from their parents, even in order to improve their overall wellbeing or extend their lives, so too placing animals in zoos is impermissible, even were their welfare to be enhanced. For most species of animals in the zoo (unlike companion and farm animals who owe their very existence to being placed in paternal relationships with humans) are capable of living in the wild apart from human interventions. Placing such creatures in zoos, therefore, whose exhibits can place severe restrictions on their movements (especially with birds, canines, felines, and primates), and are contraindicative to behaviors they would naturally engage in in the wild, is not in their best interest [18].

Other critics stress the inauthentic and imperialistic nature of zoos [26, 27, 28, 29]. Zoos involve the “praxis of imperialism,” opines Randy Malamud, wherein animals are taken out of their natural environments, confined, and exploited as “subalterns,” that is to say, placed on convenient display and subject to the gaze of countless spectators ([21], pp. 58-59). In addition, zoos are inauthentic as they fundamentally misrepresent and oversimplify the nature of the animals on exhibit ([21], p. 29). Visitors to zoos are duped into believing that the animals housed there show the full scale of behaviors they possess in the wild. Zoos, in the end, are unethical speciest institutions that unjustly confine animals and pander to base human interests. It is no wonder that Malamud thinks we should shutter zoos, when he describes them as “prisons for kidnapped, alienated, tortured specimens who are forced to live their lives in vastly unsuitable compounds for the titillation of ignorant crowds brought in by marketing and advertising campaigns that promise highbrow ecological experiences but actually pander to audiences’ less noble cravings for amusement parks, or even freakshows” ([30], p. 397).

Ralph Acampora highlights this deceptive nature of zoos ([19], p. 77). Zoos present as wild (animals exhibiting the natural behaviors they would perform in the wild as if visitors were not there) what is captive (animals as spectacle and exhibition in a “zoopticon” where they are subject to the gaze of humans). Indeed, zoos undermine the very conditions of encounter with a wild animal that they claim to provide. Zoo creatures are displayed as if at liberty, whereas, in reality, they “are incapable of living the lives they are purported to enjoy; they are prevented from participating in behavior presented as their defining characteristics. Precisely because they are unable to elude the gaze of others, to associate or refuse to associate with human beings, they are prevented from living the lives they are supposed to have” ([19], p. 78). Zoos then should be replaced with institutions that present animals more authentically such as certain types of animal orphanages or wildlife sanctuaries.

The zoo critic Lori Gruen [20], along with others [31, 32], has more recently taken up the same hammer and wedge. Gruen argues that zoos deprive animals of autonomy and dignity. Even the best zoos, those with naturalistic enclosures, are often dignity denying as they place animals under constant surveillance, deny them privacy or any hiding place to which they can retreat, and force them to be spectacles on display for humans ([20], pp. 240-245). Zoos, in fact, “are designed to create a relationship between the human observer and the object of the observation that obscures the individuality and dignity of the animals. The enclosures are designed to satisfy human interests and desires, even though they largely fail at this. At worst the experience creates a relationship in which the observer, even a child, has a feeling of dominant distance over those being observed” ([20], p. 242). Zoos also deprive animals of autonomy for Gruen [33, 34]. Zoo animals do not have the freedom to follow their own interests and engage in the behaviors typical of their species but instead are under the almost complete control of humans. They cannot choose where to dwell, nor the individuals with whom to spend time or to mate. Nor are zoo animals allowed to engage in ritualized combat to determine social hierarchies or territories. Zoos may not strictly speaking harm animals physically or psychologically, but, on account of their violating the dignity and autonomy of animals, they should be replaced with animal sanctuaries utilized primarily for conservation purposes.

While not rejecting the propriety of zoos altogether, several ethicists have proclaimed that they should be greatly modified in nature or limited in scope. For such thinkers, zoos should ideally only house animals that otherwise could not survive in the wild, or those that can be temporarily bred and reintroduced into the wild, and should generally be closed to the public [35, 36, 37, 38, 39].

Emma Marris, for example, holds that the keeping of large mammals in zoos should definitely be phased out [40]. According to Marris, the fact that many large animals, such as elephants and lions, display stereotypies in the zoo and will escape from their cages when possible, indicates that they are not happy there. Moreover, the effectiveness of zoos in conservation is minimal. Though there have been a few successful reintroductions of species into the wild, the vast majority of zoo animals will spend their entire lives in captivity. Nor is there unambiguous evidence of the educational contribution of zoos to promoting conservation. People, in fact, says Marris, “do not go to zoos to learn about the biodiversity crisis or how they can help. They go to get out of the house, to get their children some fresh air, to see interesting animals. They go for the same reason people went to zoos in the ninetieth century: to be entertained” [40]. Indeed, suggests Marris, most animals in zoos should be put in refugees or allowed to live out their natural lives without being replaced. In the end zoos should house just a few animals–namely, endangered species with a real chance of being released back into the wild and some rescues, and the rest of their space dedicated to botanical gardens.

A similar view is found in the well-known philosopher Martha Nussbaum, who builds her case to limit the species kept in zoos on a capabilities approach [41]. In order for animals to flourish, argues Nussbaum, they must be able to manifest the capacities of life, health, integrity, sense, imagination, thought, emotions, practical reason, affiliation, relations with other species, play, and control over their environment ([41], pp. 95-108). On a capabilities approach then it is not enough for zoos to ensure the absence of pain and presence of pleasure in captive animals (an area in which zoos have greatly improved, admits Nussbaum), zoos must also provide environs in which animals can lead the particular “form of life” characteristic of their species, including activities such as play, self-direction, affiliation, sensory stimulation, and even predation. A confined space is justifiable “if and only if the animals within it have access to their characteristic form of life, spatially, sensorily, nutritionally, socially, emotionally” ([41], p. 239). Nussbaum grants that zoos often support valuable research, and conservation efforts. Yet it is not clear how, for many species, they can provide for a “social life and free movement in a group-typical space” ([41], p. 239). In the end Nussbaum favors the continued presence in zoos of small mammals, amphibians, reptiles, non-migratory birds, monkeys, and some apes, but is less confident that zoos can provide the necessary environments for large mammals such as rhinos, giraffes, elephants, polar bears, cheetahs, hyenas, lions, and tigers–unless temporarily and where there are no other alternatives for a species facing extinction in the wild.

Finally, Stephen Bennett recently advanced a utilitarian argument against the keeping of sentient animals in zoos (Bennett allows the keeping of non-sentient animals, however) [15]. Bennett claims that sentient animals will suffer from frustration and unhappiness if prevented from moving about and acting upon their natural desires as they could do in the wild. Hence they experience pain under the constraints on freedom imposed by zoos ([15], pp. 178-179). Furthermore, Bennett argues, invoking the antinatalism of David Benatar [42], that, all things being equal, it is better for a sentient being not to have come into existence at all, thereby avoiding the experience of any pain, than it is to come into existence and experience pleasure. That is to say, other things being equal, the harms that occur while existing outweigh the benefits. Now if it could be shown that zoos actively promote conservation efforts then this could compensate for the harms that occur during captivity; however, zoos have achieved few successful reintroductions of animals into the wild. Thus captive breeding programs, which merely bring into existence sentient creatures who are bound to suffer some things by the very fact of their existence, and whose prospects for successful reintroduction into the wild are minimal, should be done away with and sentient animals moved out of zoos ([15], pp. 182-183).

3. Getting accurate about the contributions zoos make to research, education, and conservation

The confinement of animals in zoos has traditionally been justified on four grounds: entertainment, education, research, and conservation [43, 44]. The continued existence of zoos is said to be defensible if zoos can accomplish these goals, assuming that animals can be kept in a state of good physical and psychological health [45].

As we have seen, however, zoo critics often allege the failure of zoos to accomplish these goals, or to do much in their regard. Yet they often exaggerate these failures and so downplay the goods generated by zoos. This makes it easier to argue for their elimination. An important first step in the defense of zoos then is to accurately assess the ability of zoos to meet these four goals.

Several of the above critics have professed that zoos do not contribute much to academic research, or at least to research supporting conservation efforts ([24], p. 170, 40). Partly the claim is made that researchers are better off studying animals in the wild than in the artificial habitats found in zoos. Partly the claim is made that most of the research done in zoos involves studies on how to provide for zoo animal welfare, which would not be necessary if zoos did not exist, and little of it is solid peer-reviewed work that can assist in conservation.

While it is true that in the past zoos did not do as much as they perhaps could have to foster research, it is harder to make that case today. One study noted that from 1993 to 2013 North American AZA zoo and aquarium members contributed 5175 publications to peer-review journals, with 31.6% of those focused on veterinary science (some of which, of course, related to zoo animal welfare), 31.9% on zoology, 13.3% on ecology, and 7.3% on biodiversity conservation [46]. A similar study on German zoos, all member of ‘Verband der Zoologischen Gaerten’, described how between 2008 and 2018 such institutions produced 1058 peer-review articles, of which 13.9% were related to veterinary science, 25.1% to zoology, 7.6% to ecology, and 5.2% to biodiversity conservation [47]. And from 1998 to 2018 European EAZA zoo members produced 3345 peer-reviewed manuscripts, of which 29.1% were in veterinary science, 31.6% in zoology, 16.4% in ecology, and 12.7% in biodiversity conservation [48]. If we just limit ourselves to the areas of ecology and biodiversity conservation, zoos contributed over 2300 articles over the past 20 or so years (and the rate of publication has been increasing over time) [49, 50, 51, 52, 53]. So, although zoos may not be research institutions to the same degree that universities are, and may employ few full-time researchers, they can provide for significant research in animal biology and behavior (often partnering with university researchers), and, in particular, help inform conservation efforts involving both in-situ and ex-situ programs.

Nor is it true that studies done on zoo animals are necessarily less revelatory than those done on animals in the wild. A careful biologist recognizes that animals in zoos may not behave in ways identical to those in the wild, and hence that complementary studies in the field can be very important. Yet a lot of information about animal biology and behavior can be gleaned from research on zoo animals, who do, in fact, replicate some of the behaviors observed in the wild. Indeed, zoo animals are often more accessible and easier to isolate and interact with than animals in the wild. Hence zoos can host a lot of valuable studies on zoology and animal behavior, whether via their own employees or outside investigators. For example, investigations on the breeding behavior of the Japanese Giant Salamander undertaken at Asa Zoological Park in 1989 subsequently led to the development of artificial nests to help the species propagate in the wild [54]. And in the field of primate cognition alone over 1000 papers have been published in the new century involving research done at zoos [55, 56].

Similarly, in regard to the goal of education, critics have charged that zoos do little to change people’s behaviors in a way that make them more likely to actively support conservation efforts in the world ([15], p. 181), ([16], p. 112-115), ([18], p. 200), ([20], p. 241, 40). Moreover, they assert that most of the purported educational benefits of zoos could be arrived at equally well through other mediums, such as lectures, documentaries, books, or museums ([24], p. 169, 15, p. 181, 16, 18, p. 200).

Now the critics here are on somewhat solid ground. It is tough to demonstrate the effect of zoos on conservation attitudes or behavioral changes. In fact, critics have pointed to various studies showing that the average zoo-goer spends little time at each exhibit and leaves the zoo with views on conservation closely resembling those with which they entered [57, 58, 59]. As one author notes, “zoos seem to be successful in promoting feelings of caring and connection with wildlife, although efforts to increase visitor knowledge and pro-environmental behaviors appear to have been less effective. This may be the case because despite zoos’ efforts to position themselves as sites of conservation, research, and education, the reality is that by and large the public still views them as places of entertainment” ([60], p. 376).

However, we cannot ignore various studies that find zoos can have an impact on a visitor’s attitudes towards and behaviors involving conservation. One study noted that over fifty percent of zoo visitors found that their zoo experience reinforced their attitudes towards conservation and prompted them to reflect on their future role in its regard [61]. And while the validity of this study has been challenged [62], and responded to [63], similar studies have described small but positive impacts of zoos on conservation attitudes and behaviors, often based on feelings of connectedness with the animals rather than time spent reading exhibit signs [64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74]. The bulk of these studies though are based on survey results rather than post zoo data about actual increases in conservation behavior or spending, so more investigation needs to be done. All the same zoos can continue to refine their educational programs, and experiment with providing ways to donate or volunteer for conservation activities on site, as some have already done [73].

In any case, most modern thinkers assert that the primary value provided by zoos, and what most justifies their continued relevance, is their ability to provide for the conservation of endangered species [75, 76, 77, 78, 79, 80, 81, 82, 83, 84]. Keulartz, for example, wants zoos to make sure that their core tasks are “all geared to wildlife conservation and the species collection clearly reflects the zoo’s conservation goals. A shift towards small species, which generally experience less welfare problems in captivity and fewer behavioral problems that make return to the wild difficult than large animals, would certainly tip the scales in favor of the zoo” ([85], p. 349).

Now how do zoos fare in conservation work? Are zoos able to assist in bringing back species from the brink of extinction? Here again there is mixed success, as critics have pointed out ([21], pp. 44-45, 24, pp. 172-173, 40). It is true that zoos contain many species that are not endangered (somewhere around 8000 out of 9000 species there, in fact), and that some of the zoo populations of endangered species are quite low and so there is a danger of deleterious genes being expressed due to inbreeding. It is also true that there have been a very limited number of successful reintroductions (around 20 with 40 ongoing) and that the overall success rate has been estimated at anywhere between 10 and 40% [86, 87, 88, 89, 90, 91, 92].

Still, the successful reintroductions that have occurred should not be disregarded. Captive-breeding programs in zoos have helped in the restoration to the wild of such endangered or threatened species as the California Condor, Przewalski’s Horse, Arabian Oryx, Red Wolf, Golden Lion Tamarin, Black-Footed Ferret, Bison, Iberian Lynx, Asian Crested Ibis, and Whooping Crane. Moreover, even when not directly involved in captive-breeding programs zoos provide personnel, know-how, and funding (up to $350 million each year) for conservation efforts [87, 89, 92]. Recently zoos have done a lot of work in assisting in the restoration of endangered reptile and amphibian species [54, 92]. As has been noted, zoos help preserve threatened animal species generation after generation, by redirecting money spent on entertainment, and fostering an attitude of concern for the zoo animals who serve as ambassadors for their kin in the wild [74, 93, 94, 95].

Moreover, with advancing biotechnology (CRISPR and cloning) and monitoring technology (drones, cameras, artificial intelligence, data loggers) increased success in reintroductions of endangered species via captive breeding might be possible in the future [95, 96]. In any case, zoos can at least be important storehouses of genetic information and diversity wherein the gene pool of endangered species are maintained throughout the world through cooperative breeding programs (though here perhaps future technology might make this less necessary) [97, 98].

4. Zoos as vehicles for esthetic appreciation of, interaction with, and enjoyment of/for animals

Zoos have sponsored important research studies on animal biology and conservation, aided in a few successful reintroductions of endangered species into the wild, and made some contributions to education and changing behavioral patterns of people vis-à-vis conservation. One traditional value of zoos, however, has yet to be discussed–zoos as providing entertainment.

Zoo critics on the whole have found the least amount of support for the existence of zoos in their ability to provide for human entertainment [19, 21]. Jamieson finds it hard to see how providing entertainment to humans could possibly justify keeping wild animals in captivity ([24], p. 168). And several critics have found the very putting of animals on display in zoos to be demeaning and undignified. In the words of Gruen, “Thinking of animals as things to be looked at and believing that doing so makes for an enjoyable weekend outing, precludes seeing animals as having dignity” ([20], p. 242). For in such a case, argues Malamud, zoo life becomes merely “an amusement, a display, a spectacle in a menagerie,” where human visitors are deceived into thinking animals are exhibiting their “natural” behaviors ([21], p. 1). Tafalla expresses similar concerns in writing that “Zoos reduce animals to bodies, to a mere physical presence, to ornamental objects that can be exhibited and contemplated, to pleasant appearances we like to watch, but the true identity of an animal is much more than her body. They are subjects with different capacities, who develop and express their identity in complex behavior and through multiple relations with their environment, and with all the other individuals of the same and different species who inhabit it. This is the core of the problem. At a zoo, we cannot appreciate in a serious and deep way the esthetic qualities of wild species because zoos are not showing us wild animals on their own terms” ([99], p. 7).

Whence it might be thought that entertainment is the least important factor for those seeking to justify the existence of zoos. Yet it turns out that this, when fully explicated, is a vastly underemphasized value of zoos. Zoos can do a lot of good educating humans about animals and the environment, fostering conservation programs, and promoting research. However, zoos are primarily good as zoos, that is as a place where living creatures are kept in confinement for the purpose of being viewed and appreciated by humans. Indeed, the joy found in observing animals in the zoo is a driver of education, motivator of research, and foundation for conservation.

There is, in fact, great value in humans being able to view and be amazed by living creatures from around the world. Experiencing such animals in person allows humans to appreciate the grandeur of creation, the physical qualities, adaptations, beautiful forms, colors, and great variety of creatures living in the world. Indeed, humans can encounter species in zoos that they would not likely encounter anywhere else, such as bears, tigers, and wolverines, unless they were seasoned world travelers and expeditionists. Indeed, in very few places (perhaps one exception being the African Savannah) can one encounter such a diversity of life forms at once. Yes, it is true that one can also appreciate wildlife in films or magazines. But there is something worthwhile about seeing something in person that is hard to capture in other ways. Watching a live jazz jam session, or an orchestral performance in person, is quite different than watching the same thing on film. There are aspects of the experience that arguably cannot be duplicated virtually and the very aspect of being present at an event or occurrence encourages active engagement (though as technology develops and virtual three-dimensional presentations of material can occur there may be fewer overall differences).

So appreciation of the nature and beauty of zoo life is something that can and does occur in spite of the (mis)construals of zoo critics. If one has a conception that animals in zoos are presented in an undignified manner it may well be difficult to appreciate them esthetically. But this need not be the case (and one may be mistaken in one’s assessment of the situation–in thinking of zoo mammals as being put on display in an undignified manner). If, on the other hand, one is open to the beauty and magnificence of animals, it is there to be seen even in a zoo. Hence the fame of tigers, zebras, peacocks, toucans, and parrots. In addition, part of what makes animals esthetically appealing is their physical nature being adapted for a particular function, and this would certainly be visible in zoo creatures, and is often highlighted on informational displays [100, 101, 102]. Zoos provide a special diet for flamingos in giving them the canthaxanthin that they would normally eat in the environment to maintain their pink color but there is no reason to let this “artificiality” spoil one’s appreciation of their grace, long legs, and beauty.

Critics of zoos have asserted that one cannot have a deep appreciation of animals there as such creatures do not behave as they would in the wild. But the former in no way follows from the latter, and it is not even clear the latter follows. In a large enclosure, zoo animals can manifest many of the behaviors they do in the wild, including ones that humans can find esthetically pleasing. A lion in a zoo may not behave exactly as it does in the wild, but it can still display its magnificence as it walks with its piercing eyes, chest out, and powerful steps. So, too the plodding walk of elephants and their dexterity with their trunks, the speed of a cheetah, as well as the pacing gait and maneuverable tongue of giraffes can all be marveled at in a zoo. Zoos then can provide significant “entertainment” (perhaps “spectacle” might be a better term) for humans by allowing the aesthetical experience and appreciation of animals.

Moreover, in zoos visitors can interact with animals in various ways, such as by feeding and petting them. Many zoo critics find this artificial and problematic [25, 41]. But why? Yes, training animals to perform in ways contrary to how they normally behave may look odd (as with bears riding bicycles), and we can debate its propriety. But animal training and human-animal interactions can take various forms. Animal species (such as rhinoceroses, giraffes, tigers, wolves, parrots, and hawks) can be socialized and trained to behave or interact with humans in different ways in encounters or shows. Giraffes and rhinoceroses or parrots can be trained to happily take food from the hands of humans and birds to fly to and fro in an animal show. And animals are often able to adapt to different environments, including interacting with invasive species or new species encountered as their environment expands or contracts. Wild animals, notes Learmonth, do not just interact with members of their own species, but also with those of other species, sometimes in mutually beneficial ways. Thus “human-animal interactions could actually be considered natural in a way, and notwithstanding, be very important to animals that initiate these interactions, especially for ‘a life worth living’” [103]. At the wildland-urban interface, where farmland, field, or forest meets city, wild animals such as birds, squirrels, rabbits, or deer interact with humans in visiting feeders or salt licks or gardens. Indeed, many animals adapted to the wild may become pets in human homes (though breeding in captivity seems best for the most positive adjustment to a domestic life).

Therefore, to completely disallow animal-human interactions in a zoo and claim that these are artificial, has itself the air of drawing an artificial boundary. Nussbaum does grant the legitimacy of human relationships with parrots and chimpanzees as such interactivity is consistent with their form of life ([41], p. 238). But the ability of animals to interact positively with humans is much broader than this. Certainly most mammals that live in social groups or form pair bonds seem quite capable of forming meaningful relationships with humans, but so do some more solitary species. It does not seem possible to draw an a priori boundary but rather let such a boundary arise from seeing how different human and animal species interact in a zoo and the benefits that arise therefrom.

Zoo creatures, it could be argued, even have the unique opportunity, one lacking with wild animals, of being able to have interactions with human visitors (such as being fed or petted). This human-animal interrelationality allows for novel but positive experiences not necessarily observed in the wild, but which one might call “seminatural.” Researchers have just begun to appreciate how such animal-visitor interactions [AVIs] enhance the life of zoo creatures and of humans as well [64, 104, 105, 106, 107, 108, 109, 110, 111, 112]. For such human-animal interactions, if done appropriately, can be of great importance to zoo animals and enhance their mental well-being. Many animals seem to take delight in interacting with humans, and seek out such forms of contact, especially if trained or with known individuals. Indeed, zookeepers and caregivers and veterinarians are typically quite loving and kind and thoughtful when it comes to how to interact with zoo animals. Though she generally favors private and public animal sanctuaries over zoos, Rudy is quite right when she states that “some animals are generally better off when they are enmeshed with and connected to humans who work with them, advocate for their well-being, and love them” ([113], p. 112). Such rich and engaging relations with animals can in turn help humans bond with them, feel connected to them, experience great joy, and perhaps reinforce conservation activities. And such interactions are carefully subscribed, regulated, and evaluated for welfare impacts on the zoo creatures.

Thus, as Cochrane has argued, zoo animals are, in a way, neither wild nor domestic [114]. They live in miniature worlds, are provided with food and medicine, monitored, and moved around. They are somewhat adapted to living with humans, either being born in captivity and raised from youth with humans, and/or being extensively trained by zookeepers (indeed this is one reason why they often fail to do well when reintroduced into the wild). For these reasons, Cochrane labels zoo animals “biotic artifacts,” or creatures of “immaturation” [114]. In any case many zoo animals seem to value human interactions and such interactions can also provide positive experiences for humans and enhance their valuing of nature.

5. Some reflections on animal welfare in zoos

Still even the ability to make important contributions to research, education, conservation, and human entertainment, may not be enough to justify the placing of animals in zoos if their welfare is compromised. Most zoo critics are well aware that zoos have changed in their philosophy, and have devoted much time, energy, resources, and study to animal welfare [115, 116, 117, 118, 119, 120, 121, 122]. They are also typically aware that zoos are accredited on the basis of various standards by such agencies as the American Association of Zoos and Aquariums (AZA), the Zoological Association of American (ZAA), the European Association of Zoos and Aquaria (EAZA), and the British and Irish Association of Zoos and Aquariums (BIZA), have dedicated nutritionists, animal caregivers, and veterinary staff, and have expansive enclosures that feature naturalistic and enriched environments [123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133]. Hence it is much harder to attack zoos for their failure to provide for the core physical and mental needs of creatures in their care (though there may still be issues with particular zoos, or with certain practices such as the culling of surplus animals in overpopulated zoo enclosures, removing animals from the wild and transferring them to zoos, or questions as to whether certain species can lead fully satisfactory lives in a zoo [134, 135]).

Yet zoo critics still argue that zoos are unsatisfactory as zoo animals lack complete freedom in captivity and cannot duplicate the full scale of their activities in the wild [16, 17, 18, 41, 136, 137]. It is worthwhile exploring these issues in more detail.

Firstly, this appeal to “naturalness” is misleading, and commits the Moorean fallacy of asserting that what is “natural” is good. Producing a carbon-copy version of life in the wild in a zoo may not be optimal as far as welfare goes [138]. Browning even argues that natural functioning is neither a necessary nor sufficient condition for animal welfare, and he puts forward instead the criteria of behavioral preference and enjoyment. For some natural behaviors may decrease welfare and some unnatural behaviors increase it [139]. In the wild, animals experience predation, are challenged or attacked in social dominance conflicts, and may suffer from malnutrition, harsh environments, or disease. In captivity zoo animals are given highly nutritious food, continually monitored, provided with veterinary care, and though they may suffer from some issues not observed in the wild, in general face less overall threat to their welfare. As some have noted, in terms of comparable quality of life, zoo animals often have it better than their kin in the wild ([115], pp. 180-183, 141).

Secondly, the “natural” environment of animal species can change over time and animals may be quite adaptive, often (though not always) able to alter their behavior in response to environmental differences and do quite well. Animals such as crows and pigeons seem to flourish in cities and they are not the only species to do so.

Thirdly, zoos today continually evaluate and seek to bring about positive mental states in animals, and hence to provide them with outlets for exercise of many of their natural behaviors including habitat choice, locomotory opportunities, shelter, and foraging options [45, 140, 141, 142, 143, 144, 145]. Indeed, I would assert that by nearly all measures the vast majority of animals in accredited zoos lead happy and fulfilling lives. Moreover, it seems that even large mammals such as elephants, giraffes, bears, tigers, and lions, can lead satisfactory lives in a zoo with an appropriate environment [124, 125, 126, 127, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156]. Critics point out that many zoos no longer house elephants and attribute this to increased recognition that they do not belong in zoos. Now it is true that the welfare needs of elephants are harder to meet than for many other mammals. But it is also true that elephants get a lot of press and have motivated a lot of protests [12, 13]. Hence some of the zoos that have dropped elephants may have simply found it better from a public relations point of view to no longer house elephants rather than holding there is anything fundamentally wrong with it. In any case it does not seem there is a pressing need for zoos to switch from housing large charismatic species to insects, gastropods, amphibians, and reptiles as some have claimed ([16], p. 13) and [113, 157].

It is worth noting that determination of animal “happiness” or welfare is difficult. Animals cannot communicate their mental states as humans can and humans might falsely interpret it by misreading certain behaviors. Zoo personnel seek to make sure animals are not exhibiting signs of fear, discomfort, pain, or distress, noticeable through verbal or locutory or behavioral cues [23, 24, 120, 123, 141, 145, 157]. New techniques are even being developed for assessment of positive emotional states in animals and their connection to indicators such as facial expressions, vocalizations, behavior, and engagement in play and affiliation [142, 144]. It is recognized that the enclosures of zoo animals must provide places for shelter, rest, and access to water and food. Efforts are taken in order that zoo animals do not become “bored,” but can actively engage with their environment, and exhibit the bulk of their natural behaviors and socialize with members of their own kind [23, 24, 45, 132, 133, 134, 137, 143, 149].

There are also ongoing studies and debates about the degree to which cortisol levels in the body or stereotypic behaviors are reflective of poor welfare. Though there seem to be definite links of cortisol levels with stress, in certain cases there can be high levels of cortisol with little obvious stressors or low levels of cortisol in spite of fairly clear signs of stress. Again, stereotypic behaviors, such as pacing, can be indicative of boredom and stress and linked to higher cortisol levels, though such behaviors may also be anticipatory (linked to expected arrival of a keeper or the opening of a door to a new location) or compensatory (a means of reducing stress) [144, 158, 159, 160, 161]. Research continues in these areas. And other questions arise. Is inability to reproduce a sign or poor welfare or not? Animals often adjust reproductive rates due to match environmental size, so it may not be. Is proclivity to flee cages a sign of distress? Perhaps, or it may merely reflect the natural curiosity of certain species and individuals. Such questions can and are being studied. Much work remains to be done to determine the best markers of optimal and poor welfare among zoo animals. Further study, of course, might suggest requirements for the wellbeing of certain animal species in captivity that some (or even all) zoos are not capable of meeting. And if the evidence suggests some species are just not capable of a quality life in a particular zoo (or zoos in general) then modifications should be made or the animal species moved to more appropriate locations such as sanctuaries.

It is true that zoo animals have less freedom than their kin in the wild, but the question is whether or not zoo animals, including mammals, suffer as a result. Is freedom a true value for non-human species or sentient ones? Arguably not. Freedom only seems to be an overriding value for a creature that can know it is not free. Freedom must be missed for absence of freedom to be a true deficit. Yet most animals have no conception of such a thing. They cannot contrast their current state of life with that of a life in the wild and regret missing out on the latter. So, it is not clear that zoo animals perceive enclosures as a restriction of freedom or their zoo home as a limitation of their own choices [162, 163]. As Cochrane notes: “Most animals cannot frame, revise and pursue their own conceptions of the good. This is not to say that sentient animals do not have different characters, nor is it to deny that they can make choices. It is simply to make the point that most animals cannot forge their own life plans and goals. Given this, restricting the freedom of these animals does not seem to cause harm in the same way that it does for humans. … As autonomous agents, most human beings have a fundamental interest in being free to pursue their own life plans, forge their own conception of a good life and not to have a particular way of life forced upon them” ([164], p. 669). There is a sense for sure, as Jamieson notes, that it is morally preferable to be free rather than captive ([24], p. 180). Hence taking animals out of the wild and placing them in captivity does come with a certain “cost” and must be done for an appropriate reason [1, 2, 3, 4, 5, 6]. Nature may offer opportunities for exploration and socialization not available in captivity. Yet nature also offers challenges and potential suffering, and a life in captivity may be just as fulfilling as one in the wild for many animal species. Thus, placing animals in zoos, where they can lead happy lives, even if they lack certain opportunities found in the wild, does seem justifiable if done for the reasons noted above, human appreciation and interaction, education, research, and conservation. Such captive animals need not see lack of freedom as a disvalue and may find all the requirements they need for a good and satisfying life in a captive situation, and indeed find unique opportunities not available in the wild (such as forming animal-human relationships). In any case ongoing studies and efforts are being undertaken to make sure animal species in zoos are receiving the “liberty” needed to lead quality lives. Animals are not as intelligent as humans, or as aware of their environment and possibilities of choice, and so arguably do not require the same level or range of freedoms as humans; still some level of freedom to explore their environment and behave as they want to does seem necessary for zoo animals [164]. The challenge is to understand what level of freedom is necessary. Placing animals in zoos does seem valid as long as animals are provided a certain level of freedom and important values can be met by placing them in captivity.

6. Defenders of zoos

In short, zoos overall have great value and should continue to exist. They provide for human entertainment, human appreciation of creation, interspecific interactions between humans and animals, education, research, and conservation. They should, all the same, continue to monitor and improve in their ability to maintain animal welfare, impart education, and contribute to conservation activities.

Similar sentiments are found in a few other philosophers [98, 165, 166, 167, 168]. Bostock, for example, in his Zoos and Animal Rights (1993), argues that zoos are very valuable in terms of safeguarding the genetic information of various species and reintroducing these species into the wild if and when necessary [169]. Bostock finds zoos particularly important in allowing humans to observe wildlife, something that millions of people could never do by visiting the wild, without irreparably changing it for the worse. Bostock points out that zoo animals are partially domesticated and so do not require the same range of behaviors to be satisfied as completely wild animals do, and that, in turn, domestic animals themselves have retained a large number of the behaviors they had in the wild. Zoos can and should maintain their exhibits and programs in conservation and education as long as they can provide for the well-being of captive animals in terms of health and ability to engage in a variety of natural behaviors.

DeGrazia also defends the existence of zoos as long as they are able to provide their captive residents with at least as good a life as they would otherwise have in the wild ([170], pp. 294-297), ([171], pp. 759-760). For life in the wild is often nasty, brutish, and short, to use the words of Hobbes, and full of hunger, disease, and pain. Conversely zoos, though they confine animals, are able to provide them with a good life as long as they can meet their basic needs and furnish enough opportunities for fulfilling their typical behaviors; indeed, with their advanced veterinary care zoos may furnish longer life spans for animals than in the wild. According to DeGrazia, zoo exhibits which allow for a good life for captive creatures, while also allowing for humans to admire them, contrary to what critics have claimed, do show the animals respect. Being subject to the observation of humans need not deprive animals of dignity. DeGrazia, though, is not a fan of capturing wild animals and transferring them to zoos (especially intelligent species such as birds and mammals), but instead favors breeding them in captivity.

Finally Gray, in her Zoo Ethics (2017) argues that zoos can increase the likelihood of humans taking action to preserve animal species by enhancing people’s appreciation and understanding of biotic communities ([172], pp. 181-182]). Zoos can help keep the remaining representatives of endangered species alive as they work to secure populations in the wild for these species in the future. Gray, however, does push for compassionate conservationism and the need to carefully provide for the welfare of each animal in the zoo.

7. Conclusion

Animal rights ethicists and activists have criticized the treatment of animals in zoos of late. We can be grateful for some of their efforts. For it has given impetus to the investigation and improvement of the welfare of animals in zoos. At the same time, many of their critiques are based on dubious philosophical grounds, such as the premise that the best life for a creature is one that mimics its life in the wild, that zoo animals suffer harm from a lack of freedom, or that animals in zoos are merely there as cute artifacts for the eyes of visitors and that putting them on display denies them dignity. Critics of zoos also tend to exaggerate the mistreatment of animals and zoos or devalue the positive contributions zoos can make to research, education, and conservation.

In modern zoos great effort is put into maintain the welfare of the creatures there (at least with institutions accredited through prominent associations such as the AZA, BIZA, EAZA, and ZAA). Zoo animals are well cared for, given fairly large and enriched environments, and offered a variety of foods and activities. Indeed, zoo animals can interact with other members of their species, as well as members of other species including humans. Thus, animals in zoos are provided with a broad array of activities, some even going beyond those afforded in the wild. Moreover, zoo animals will typically enter into such activities voluntarily and find pleasure in them. They can take pleasure in being fed or petted by humans. This is reflective of the adaptivity of animals living in the wild and the extent to which they are able to interact with members of their own, other species, or new “invasive” or encountered ones. Such novel interactions need not be considered unnatural or artificial or improper. Just as parrots or pigs or monkeys can come to find value and satisfaction living in humans’ homes, so too can other species that are typically restricted to the wild. All of which is to say that zoos can furnish a quality life to the animals in them, including even large mammals if provided with a proper enclosure.

While taking care of and providing positive forms of existence for the creatures in them, zoos can also achieve several other goods. They can provide for an enjoyable day for human visitors, help humans appreciate the grandeur and diversity of creation, and allow for mutually positive interactions between humans and zoo animals. Zoos can, in addition, help educate humans about animals and their danger of extinction, connect people to animals and motivate conservational attitudes and behavior, promote research into zoology, animal welfare, and conservation, and help to preserve the gene pools of species and prevent them from going extinct in the future. This paper is thus a call for zoo critics, or at least those of them with open minds, to reconsider their positions, and to recognize there is no reason that zoos should not exist long into the future.