AR-FAQ - #69

#69 Don't zoos contribute to the saving of species from extinction?

Zoos often claim that they are "arks", which can preserve species whose habitat has been destroyed, or which were wiped out in the wild for other reasons (such as hunting). They suggest that they can maintain the species in captivity until the cause of the creature's extirpation is remedied, and then successfully reintroduce the animals to the wild, resulting in a healthy, self-sustaining population. Zoos often defend their existence against challenges from the AR movement on these grounds. There are several problems with this argument, however. First, the number of animals required to maintain a viable gene pool can be quite high, and is never known for certain. If the captive gene pool is too small, then inbreeding can result in increased susceptibility to disease, birth defects, and mutations; the species can be so weakened that it would never be viable in the wild. Some species are extremely difficult to breed in captivity: marine mammals, many bird species, and so on. Pandas, which have been the sustained focus of captive breeding efforts for several decades in zoos around the world, are notoriously difficult to breed in captivity. With such species, the zoos, by taking animals from the wild to supply their breeding programs, constitute a net drain on wild populations. The whole concept of habitat restoration is mired in serious difficulties. Animals threatened by poaching (elephants, rhinos, pandas, bears and more) will never be safe in the wild as long as firearms, material needs, and a willingness to consume animal parts coincide. Species threatened by chemical contamination (such as bird species vulnerable to pesticides and lead shot) will not be candidates for release until we stop using the offending substances, and enough time has passed for the toxins to be processed out of the environment. Since heavy metals and some pesticides are both persistent and bioaccumulative, this could mean decades or centuries before it is safe to reintroduce the animals. Even if these problems can be overcome, there are still difficulties with the process of reintroduction. Problems such as human imprinting, the need to teach animals to fly, hunt, build dens, and raise their young are serious obstacles, and must be solved individually for each species. There is a small limit to the number of species the global network of zoos can preserve under even the most optimistic assumptions. Profound constraints are imposed by the lack of space in zoos, their limited financial resources, and the requirement that viable gene pools of each species be preserved. Few zoos, for instance, ever keep more than two individuals of large mammal species. The need to preserve scores or hundreds of a particular species would be beyond the resources of even the largest zoos, and even the whole world zoo community would be hard-pressed to preserve even a few dozen species in this manner. Contrast this with the efficiency of large habitat preserves, which can maintain viable populations of whole complexes of species with minimal human intervention. Large preserves maintain every species in the ecosystem in a predominantly self-sufficient manner, while keeping the creatures in the natural habitat unmolested. If the financial resources (both government and charitable), and the biological expertise currently consumed by zoos, were redirected to habitat preservation and management, we would have far fewer worries about habitat restoration or preserving species whose habitat is gone. Choosing zoos as a means for species preservation, in addition to being expensive and of dubious effectiveness, has serious ethical problems. Keeping animals in zoos harms them, by denying them freedom of movement and association, which is important to social animals, and frustrates many of their natural behavioral patterns, leaving them at least bored, and at worst seriously neurotic. While humans may feel there is some justifying benefit to their captivity (that the species is being preserved, and may someday be reintroduced into the wild), this is no compensating benefit to the individual animals. Attempts to preserve species by means of captivity have been described as sacrificing the individual gorilla to the abstract Gorilla (i.e., to the abstract conception of the gorilla). JE