630 | Zoos: Roles whose animals, many of them in large, naturalistic, and/or behaviorally enriched enclosures, often give every indication of being in a state of wellbeing The question remains whether it is still misguided, as some feel, to maintain wild animals, how ever well cared for, outside their natural habitats, to which millions of years of evolution have adapted them Zoos and their critics agree now that wild species must be protected, and reputable zoos now take very few animals, especially mammals, from the wild, though they need to this occasionally for serious conservational reasons If it is acceptable to keep domesticated animals, perhaps it is not wrong to keep what can only be relatively wild animals in zoos Indeed, some of them could be argued to be slightly domesticated because of their individual adjustment to zoo conditions, or because of some perhaps unavoidable selective breeding It is true that many domesticated animals, such as intensively reared hens and pigs, are kept in appalling conditions, but this is because of economic greed, not because they cannot be kept humanely Zoo animals’ captive environments can similarly be vastly improved by studying their behavioral requirements The degree to which animals show their natural behavior is a main criterion for judging their wellbeing or otherwise, as well as a guide to how their facilities may be improved Other criteria include their degree of physical health, their readiness to breed, and the degree to which they show abnormal behavior such as the stereotyped weaving of some captive polar bears If animals in zoos are only relatively wild or even slightly domesticated, this makes keeping them more acceptable, but at the same time it casts doubt on zoos’ claim to maintain truly wild animals, and on whether these animals or their descendants could successfully be reintroduced to the wild This is one of many real problems for zoos, and some critics deny their ability to save animals who are wild in any meaningful sense On the other hand, zoos now have elaborate conservational arrangements to help to maintain their animals’ wildness, at least genetically These include studbooks for many endangered species and computerized, linked animal records (part of ISIS, the International Species Information System, started thirty years ago) to assist in the management of zoo animals as members of total captive populations with minimal inbreeding and maximal genetic diversity, as in a wild population Enlightened zoo conditions help to maintain behavioral wildness also Successful reintroductions have already occurred, such as the reintroduction of the Arabian oryx However, just how successful some reintroductions have been, for example, that of the golden lion tamarin, is arguable Thus zoos’ ability to save, or at least reintroduce, many wild species remains unproven However, threats face many wild species, from the hunting of rhinos and tigers to the threats to almost all wild habitats from the exploding human population, and zoos can help considerably Again, some critics see a concentration on captive breeding as a dangerous distraction from the primary conservational task of protecting actual wild habitats But zoos see their captive breeding as merely complementing this, and some zoo scientists assist greatly in the protective management of actual wild populations Many more zoos help to educate the public about threats to wild habitats Zoos’ conservational roles also bring their own moral problems, such as whether saving endangered species can