Sorry... I guess I just don't quite make the connection between a few articles pulled off the internet referencing escaped zoo animals and the comment that animals "would rather die than live impeded lives in zoos or sanctuaries." Firstly, that significantly anthropormorphsizes the animal psyche and secondly I could probably find just as many articles describing an animal chewing its own leg off to get out of a trap - an act that would seriously limit it's ability to survive in the long term yet performed nonetheless for immediate survival.
Suicide is, at least so far as I can find, a strictly Human expression. If someone can show me where I'm wrong, I'd welcome the correction.