Packs of herbivores stomp on poor plants all the time and eat them, leaving just barren dirt behind them, carnivores leave the rest of their prey, like bones, instead of recycling them, and some of them, like polar bears, make dens for their cubs, changing the way the place look. There are other species of bears who scratch trees and hurt them. How can we allow them to continue mauling the plane without doing something?
Why would THEY have to reduce it? They're not even smart enough to know what a footprint is. No offence man, but that is kind of a stupid question. We humans are the ones who must change our lives, not our animals. We use more resources, and pollute everything we have to is that we can sustainn our current living style we have now.