An Immense World: How Animal Senses Reveal the Hidden Realms Around Us

by Ed Yong

Sensing can feel passive, as if eyes and other sense organs were intake valves through which animals absorb and receive the stimuli around them. But over time, the simple act of seeing recolors the world. Guided by evolution, eyes are living paintbrushes. Flowers, frogs, fish, feathers, and fruit all show that sight affects what is seen, and that much of what we find beautiful in nature has been shaped by the vision of our fellow animals. Beauty is not only in the eye of the beholder. It arises because of that eye.

Pain does not exist for its own sake. There’s no reason why anything should hurt. Things hurt so that animals can do something with that information. And without understanding their needs and their limitations, it’s hard to interpret their behavior correctly.

Through centuries of effort, people have learned much about the sensory worlds of other species. But in a fraction of the time, we have upended those worlds. We now live in the Anthropocene—a geological epoch defined and dominated by the deeds of our species. We have changed the climate and acidified the oceans by releasing titanic amounts of greenhouse gases. We have shuffled wildlife across continents, replacing indigenous species with invasive ones. We have instigated what some scientists have called an era of “biological annihilation,” comparable to the five great mass extinction events of prehistory. And amid this already dispiriting ledger of ecological sins, there is one that should be especially easy to appreciate and yet is often ignored—sensory pollution. Instead of stepping into the Umwelten of other animals, we have forced them to live in ours by barraging them with stimuli of our own making.