We already consider ourselves gifted in empathy. We invented the Golden Rule. Now all we need to do is extend it to cover other species. The legal status of wildlife is also affected by this notion of rights. But we don't afford wildlife that same right.
Wildlife are above our laws.
It may seem fanciful to suggest that we can guess what other species are thinking or feeling, but we actually have quite a lot of genetic commonality, so it isn't really so far-fetched to think that we might be able to have similar thoughts and feelings. In spite of all their excellent and very persuasive arguments in favor of preserving other species, I think that the authors missed one of the best reasons of all. All over the world, humans are fighting. In every case, the motivations are selfish ones. One country wants resources that another one has.