Lions eat second-hand grass by eating grass-eaters! Indirect relations connect everything, from the insects that pollinate flowers to the carnivores that won’t touch leafy food. Like some people who don’t eat salad. There isn’t a food chain in the wild, but a multidimensional and dynamic matrix. A very complex system of interconnectedness keeps all species alive in nature; sometimes dropping one. This interconnectedness means interdependence. There is a delicate balance among all the participants in every micro-ecology on earth.
The fortunes of one species occasionally changes, affecting the equilibrium of a few or many species around it. Some reversible or cyclic changes occur among the living, as well as permanent evolutionary ones, followed by chain reactions of unknown duration and reach. All this continuous change is life on earth.
What is different in our time? Three views are possible.
The first: People have for now won the contest against all the other species hands down, barring some micro-organisms! We don’t only change things on earth as we choose, we dominate all life. People remove unwanted forms of life or use them up, even some cherished ones, like rhinos. We interfere with life wherever we find it. Names describing this onset of human domination of the living on earth are taking root: the Anthropocene or Homogeocene has arrived (Wikipedia). By this is meant an informal geological epoch, a phase of significant human impact on ecosystems on earth. It implies we’re racing ahead, promoting our own interests like a virus by obliterating the rest.
The second, opposing view: Nothing is significantly changing around us as a consequence of what we do. It’s all alarmist greenie disease and there will always be lions like this for the people to see. The earth’s temperature is always changing cyclically, not a problem we caused. God manages the earth, the universe; people attend to lesser things.
The third, a compromise or synthetic view: Governments are striking an adequate balance through nature conservation and all. Our management efforts are not cosmetic. Development is sustainable and biodiversity is safe. Our children have a safe future.
One of these scenarios is closest to reality, representing best what is happening and what will come to pass in the future. Take your pick. Act accordingly. Live your dream.