What is the importance of wild animals? How can they be protected?
The importance of wild animals does not depend on how much they can produce for us. They are important because they all even each other out into a balanced and effective ecosystem, along with abiotic factors. The apex predators are the most important, because they act as a governing body of sorts for the ecosystem. They make sure that none of the prey eat too many plants, or have offspring beyond the carrying capacity of the ecosystem. Without them, as seen in Yellowstone National Park with elk after the wolves there were slowly killed off by humans, the preys' numbers will get out of hand, and they will decimate the plant populations, causing devastating trophic cascades that effect all biotic and abiotic factors in the ecosystem. The prey and supporting predators are also very important, because the predators obviously all depend on the prey to live, and the supporting predators might keep other prey populations in check. No one knows what the overall purpose of all wild animals is, and there might not be one, but in my opinion, they are important anyway because they all have lives, and they all support a very organized system.
Wild animals can be protected, in my opinion, by starting breeding programs for endangered species, putting more emphasis on the original purposes of zoos, and giving them the land they need. Breeding programs for endangered species have been very successful in the past, and I think they should be used frequently. They might not completely fix the ecosystem of the animals, but at least we can get their numbers up, and learn more about their behavior while doing it.
The original purposes of zoos were to keep members of endangered species safe, and to educate the public about animals and ways to help them. However, while they have a lot of potential, most zoos fall flat on delivering for these two purposes. For example, most zoos do not actually keep that many endangered animals, just iconic ones. They also don't really show the public ways to help the animals that often. Most zoos follow these purposes a little, but they could do much more.
This last point would actually be pretty difficult in execution. Admittedly, I am not an expert on what it usually takes to clear out a big enough area for animal species to live, and I do know that this also has problems. If animals just live in isolated wilderness reserves, they will not have a big enough gene pool, and dangerous levels of inbreeding can occur. Also, if the wild animals are living next to farms, that can be dangerous. If hunters eliminate their prey, they will have no choice but to eat livestock, which will probably result in their deaths. A lot of people also overestimate how dangerous a lot of wild animals are, which can lead to more deaths. However, most biologists care immensely about protecting wild animals, and they will probably be able to find solutions to these problems. I plan to join them as soon as I can.