You don't want to hear the truth, but the very opposite is the case.
The cruelest thin you could do is releasing zoo animals.
One example,,Batworld sanctuary primarily rescues bats, they have full blown medical facilities including nurseries for orphans, they are protected, fed, and cared for by professionals, their enclosed habitat more than suitable with all the enrichment's and exercise they need, those that can go back to the wild are put into bat castle with their own kind and free to come and go as they choose.
If you knew truths such wildlife facilities like Seaworld, San Diego zoo and most others are just the same.
Too many people fall for too many lies from the PETA activists,,,don't be another sheeple.