you might know more about how to define unhappiness vs. depresssion, than I do. And if that is the case, I obviously respect this.
There is no doubt, however, that some caged zoo animals are unhappy / sad or whatever you want to call it. Don't you agree?
No, I don't. What evidence do you have that they are unhappy? Especially the way modern zoos are kept today. If anything, certainly compared to their wild counterparts, they live a carefree life of luxury.
I lived next door to a kennels growing up. It was where they housed animals in cages for the Vet hospital about a half mile away. Now this was in the sixties and early seventies where they didn't give a crap about "animal conditions".
I was probably about 8 years old when I started helping out with the up keep. It was keep by a family that lived in a house and the kennels were in back. They probably housed maybe twenty dogs at any given time. One of their kids was my age and my best friend at the time. We both loved taking care of the various breeds of dogs. I would venture to say that their cage was about 10 feet square so they could walk around a bit.
It's hard to describe the area but it was also an area where we kids could hang out and play. Now, if we were playing and ignoring the dogs they just laid there and slept -- just like my dogs do when I'm away or in the house. When we would get their attention, either to feed them or play with them, they would immediately snap to attention, tail wagging, with that eager doggy smile expression. Just like my dogs at home do.
Never ever did I ever get the impression that they were in anyway sad or depressed.
In my neighborhood there is a family that raises Pit Bulls. I think they keep them in horrible conditions. They keep them in cages which must be five feet square. They can barely walk around. Whenever I see them they're just sleeping. If they notice me they immediately jump to attention and start barking wildly. When their owner comes out they wag their tail and look happy and eager. No doubt because one of the few times the owner pays attention to them is to feed them so they associate him with something positive.
Do you really think the Pit Bulls are thinking, "You know, this blows. Look at this place. I can hardly move. I'd so like to bite the shit out of that mofo that occasionally snoops around here but I'm locked up in this fucking cage."
It's fed, it sleeps all day like all dogs do. It's physically comfortable. It's not thinking about what else it would like to do.
In essence, they are really too dumb to realize how miserable they should be.
Compared to modern day pets, which lives a carefree, comfortable life; an animal at the zoo is living the dream. When was the last time you went to a zoo? Compare that with how they live in the wild.
An animal at a zoo dies of old age. There's no such thing in nature. Once you slow down you're a walking target and will be killed.