Nobody suggests that the wild is "unicorns and rainbows" or like a scene out of a Disney movie. It can be dangerous and brutal, but it can also be challenging (in the most positive sense of the word), diverse, exciting, and, importantly, it is where animals can live in the way in which they have adapted to live over millennia. Group make-up and hierarchies, social interactions, climate, habitat, diet, natural range and behaviours can all be experienced as they should be. Life can be lived as it was meant to be; and that counts for something. Of course some animals will suffer in the wild and of course animals will die in the wild, but to pretend that locking animals up and frustrating many, if not all, of their natural behaviours is somehow for their benefit and will protect them from the perils of the wild is, in my view, misguided.
One of the reasons put forward that animals cannot be released to the wild is that they have been born in captivity and thus would not have the skills to survive if released. This is, in fact, one of the arguments that I agree with. Conversely, one of the reasons that zoos exist is, it is claimed, is to be "a place to keep wild populations genetically viable on the slim chance that humans will stop being greedy and zoos will be able to one day return these animals to the wild". So on the one hand, it is accepted that many animals in zoos would be unlikely to survive release and, on the other hand, animals are kept in zoos for the eventual purpose that they should be released. Something doesn't add up.
The logical response to this argument is that zoos are therefore not the answer. If animals in zoos cannot be released then the only option must be to focus on conservation of wild habitats and tackling the issues "on the ground". This is the approach which anti-zoo campaigners generally advocate as it is firmly believed that in-situ conservation which deals with all issues (environmental, socio-economic, cultural, local and global) is the only way in which to effectively protect habitats and species. Nobody claims that this is easy, or even possible, but to suggest that zoos offer the silver bullet that will be the solution is to ignore that zoos have existed for centuries and yet environmental degradation is continuing unabated at an alarming rate.