Many captive bred animals struggle to survive in the wild, as they have no knowledge of how to obtain food, find shelter, or avoid predators. This is because they have previously relied on humans to provide it for them. So if you do release a finch, it will likely die within a short length of time. If it is released and manages to survive in an area that is not its native country, it may out-compete or threaten other native species of birds. So it is best to keep captive pets captive and not release them into the wild.