I'm also interested in the ethics of keeping an animal in captivity and out of its natural environment (again, from a pro point of view).
I don't know of any links, but here are a few thoughts (and their counterpoints)....
1. Captive bred reptiles decrease the pressure on wild populations. (This is at least theoretically true for some species, although many people are greedy and sell cb animals for more than the price of wild caughts, thus increasing the pressure on wild pops, not decreasing it.)
2. Captive bred reptiles live longer and are exposed to less danger than wild caught reptiles. (This arguement is fraught with all sorts of philosophical problems, but it is one that is put forward).
3. Wild habitats are being destroyed at such an alarming pace that the only refugia for many species is going to be in captive populations (e.g. the Round Island Boas). (The arguement against this is "what's the point?" Why maintain captive populations of species that have become extinct in the wild?)
and the follow-up...
4. Theoretically a captive population could be used to restock areas if the cause of the initial extirpation could be eliminated - such as elimination of introduced mongooses, cats, goats, or a reforestation program. (The arguement against this is that a captive populations need to be carefully managed to prevent inbreeding if a viable population is to be maintained for reintroduction. That isn't happening in most species outside of institutions like zoos. Add to that the fact that many restocking efforts fail.)
Just a few thoughts.
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Chris Harrison