Catching up on unread articles in The New York Times Book Review's year-end issue, I opened to the section on what they judge to be the ten best books of 2022 and realized that I'd been reading one nonfiction choice nightly, An Immense World: How Animal Senses Reveal the Hidden Realms Around Us by Ed Yong, for a week or so. They provided a cover image, a capsule review rich with merited praise, and a short excerpt, part of a paragraph about the speed and power of a striking rattlesnake that I'd already read and remembered well. Upstairs at my nightstand, I leafed through the book, pausing at each dogeared page where scenes or observations had caught my attention on various nights. Rich in vivid description and significant information about the animals it discusses, the book continually expands the reader's awareness of how all kinds of creatures operate in the world.
Yong draws on an amazing range of research—most pages throughout the book include footnotes adding to the informative paragraphs above and his extensive bibliography runs 45 pages—sharing not only abundant scientific reading but also onsite conversations with various researchers to learn what distinguishes the sensory ranges of all kinds of creatures. Chapters center on smells and tastes, light and ways of seeing, color, pain, heat, sound, and contact, as well as sensory powers humans might not know they themselves have or once had, powers other very different creatures consistently rely on.
Yong begins the book demonstrating how seven creatures in the same physical space might "experience it in wildly and wondrously different ways." As the book will show us, "every animal can only tap into a small fraction of reality's fullness," because each creature is "enclosed within its own unique sensory bubble, perceiving but a tiny sliver of an immense world." He introduces the key term Umwelt: "the part of those surroundings that an animal can sense and experience—its perceptual world," and uses the term Umwelten throughout the book to distinguish different ways that different creatures discern their world. For example, the chapter on electric fields examines such creatures as knifefishes and elephantfishes that "use their electric fields to sense their surroundings, and . . . communicate with each other. Electricity is to them what echoes are to bats, smells are to dogs, and light is to humans—the core of their Umwelt." Yong makes a good case for his assertion that "[t]o stand a chance of knowing what it is like to be another animal, we need to know almost everything about that animal': its senses, nervous system, needs, environment, "evolutionary past and its ecological present."
Examples abound throughout the book, encompassing an almost encyclopedic range of creatures. For example, observing heat-sensitive pits behind a rattlesnake's nostrils, Yong tells us they evolved among three groups of snakes, "two non-venomous constrictors, pythons and boas," and "the highly venomous and aptly named pit vipers—cottonmouths, copperheads, moccasins, and rattlesnakes." He points out that "a pit viper can detect the warmth of a rodent from up to a meter away. A blindfolded rattlesnake that's sitting on your head could sense the warmth of a mouse on the tip of your outstretched finger."
Such facts surface about other creatures throughout the book. For example: "Around 350 species of fish can produce their own electricity, and humans have known about their ability since long before anyone knew what electricity was." And: "After a busy night of insect-catching, big brown bats use a compass sense to return to their home roosts. After an early life in the open ocean, baby cardinal fish use a compass sense to swim back to the coral reefs where they were born. Mole-rats use their compass to find their way through their dark underground tunnels."
As exhilarating as his revelations about all kinds of creatures are, there's a darker aspect to what we learn. In his final chapter Yong details the ways humans have profoundly altered the Umwelten of Earth's other creatures. "We are closer than ever to understanding what it is like to be another animal, but we have made it harder than ever for other animals to be."
He heightens our awareness of where our world is now: "We normalize the abnormal, and accept the unacceptable. Remember that more than 80 percent of people live under light-polluted skies, and that two-thirds of Europeans are immersed in noise equivalent to constant rainfall. Many people have no idea what true darkness or quiet feels like . . . . As the problem of sensory pollution grows, our willingness to address it subsides." He asks, "How do we solve a problem that we don't realize exists." This book makes us more profoundly aware and gives us hope that we'll find a way to address it.
Notes: Yong, Ed. An Immense World: How Animal Senses Reveal the Hidden Realms Around Us. New York: Random House, 2022.