John James Audubon was wrong. The great naturalist may have illustrated and compiled 1827’s Birds of America, a pioneering work of ornithology, but thanks to a series of sloppy experiments on turkey vultures, he insisted that birds can’t smell. This was taken for granted until the 1960s when two women scientists in New Zealand proved otherwise, but we are still discovering just how discerning bird’s noses can be. In the 1990s, biologist Gabrielle Nevitt was puzzling, as human beings have for millennia, over the ability of seabirds to locate food and accurately navigate long distances over seemingly blank ocean. When a climate scientist casually mentioned a chemical released into the air when plankton are eaten by krill (tiny animals that make up the diet of many ocean denizens), Nevitt realized that this might be just the clue she was looking for. Soon she learned, as Ed Yong describes it in his new book, An Immense World: How Animal Senses Reveal the Hidden Realms Around Us, that where human beings see a featureless ocean surface, the birds perceive “a seascape of odorous mountains and unscented valleys,” smells that formed “a secret topography invisible to the eye but evident to the nose,” guiding them not just to their next meal but back across the sea to home.
Like a lot of great science writing, An Immense World is a catalog of such wonders. Yong found birds that can see colors invisible to the human eye, seals that can follow the trail of objects by minute disturbances in the water, and crickets with hairs so sensitive they can detect the passage of a single photon. But—pardon the anthropocentricism—what does this mean to the humans reading Yong’s book? The revelation of these superpowers, he implies, should remind us that “animals are not just stand-ins for humans or fodder for brainstorming sessions. They have worth in themselves.” To him, their difference from humans is where that worth resides, although this argument is only half-baked. Why should difference in itself be valuable? Does everything able to do something that human beings can’t—a plant, a river, a cloud, a computer program—enjoy the same status as animals?
Certainly, An Immense World works as a corrective to the presumptions of human beings. Yong travels from bat lab to spider lab to fish lab, where scientists enthuse about the incredible perceptive powers of the species they’ve chosen to study and recount the ingenious experiments they’ve used to measure how animals deploy their senses in ways humans can’t. The history of our observations of our fellow creatures is a series of corrected mistakes and solved mysteries as we’ve gradually realized that animals don’t perceive and experience the world as we do. [Continue reading…]