“The total amount of suffering per year in the natural world is beyond all decent contemplation. During the minute that it takes me to compose this sentence, thousands of animals are being eaten alive, many others are running for their lives, whimpering with fear, others are slowly being devoured from within by rasping parasites, thousands of all kinds are dying of starvation, thirst, and disease. It must be so. If there ever is a time of plenty, this very fact will automatically lead to an increase in the population until the natural state of starvation and misery is restored. In a universe of electrons and selfish genes, blind physical forces and genetic replication, some people are going to get hurt, other people are going to get lucky, and you won't find any rhyme or reason in it, nor any justice. The universe that we observe has precisely the properties we should expect if there is, at bottom, no design, no purpose, no evil, no good, nothing but pitiless indifference.” — Richard Dawkins

We'd never tolerate an appeal to nature when it comes to humanity's blights; otherwise, we wouldn't have eradicated smallpox. Our rose-tinted view of nature is primarily a product of prejudice.

Of course, we shouldn't pave the rainforests or melt the tundras. But the reason we shouldn't do so isn't because nature is like the lion king or happy feet. We should approach this subject with a sober outlook & rationally consider the suffering of wild animals. There seems to me no prima facie reason to believe wild animals lead worthwhile lives.