Everyone seems to have that one question that if anything ultimately shifts the way people think about zoos: Are they good or bad? The answer is GOOD obviously, and here is why.
"Zoos are prisons." People might see that as a prison and the definition of prison is a building in which people are held for crimes against humanity. So, is a zoo a prison? No. First off they are not people, they are animals. Second, what crimes have they committed? None. Yet people see enclosures as a prison.
Imagine this: You're sitting at home. Quite content with yourself. You have food a mere walking distance away, giving you no need to go hunting or gathering. You have shelter, food, great medical care, and all around alone without the stress of having to defend your home from rivals or those who want to take it from you. Thats what it's like for animals in the zoo. They have food. There is no need for them to travel hundreds upon hundreds of miles a week looking for food. They have shelter, there is no need to constantly fight to keep it. Yes, they look lazy, but we are too.
"Animals in the zoo should be released back into the wild where they belong." This can be agreeable to some points. Thanks to the SSP (species survival program) zoos are breeding animals and re introducing their offspring back into the wild. However, releasing an animal into the wild who has spent its whole life in a zoo is a bad idea.
Imagine this: You are at home when all of a sudden, someone comes and throws you out of your home, into the wild with no preparation, and expecting you to know off the top of your head how to find shelter, hunt, and over all survive without human help. It's practically a death sentence, which is what it's like for animals forced into release.
The movie about the orca in Free Willy named Kekio, was born in captivity. Raised, cared for and train by humans, he came to depend on them. However, when people began protesting on how "Wily" was not free, the clock on Keiko's short life began running out. Trainers began hastily trying to prepare the 5-year-old whale for release. Eventually, he was released only to be found dead 3 years later. The poor whale sought human contact and chose a whaling boat to seek it. It's the same for animal in the zoo. Sure that fight instinct is there, but hunting is a learned trait. If you release a tiger that spent 10 years in the zoo into the wild what do you think would happen? He would either get shot, due to not understand that humans should be feared. Starve to death, because he would not know how to hunt large prey. Or killed by a rival tiger.
We need zoos. They help us understand animals and even help their species survive through breeding programs and more.