Attempts to counterbalance population losses often center on breeding programs. In some situations, all members of a small, extremely endangered population are captured and held in protective custody (captive breeding) until careful management can help their numbers to increase to the point where of them can be released back into the wild.

There were, and still are, loud, nasty debates over the reintroduction of wolves into areas through which they historically had roamed for thousands of years, e.g., Yellowstone National Park in Montana. After the wolves had initially been driven and hunted out some years ago, the food chains in those areas had become very imbalanced as the populations of some organisms swelled and others declined.