Each of us experiences the world differently. Two people living in the same house go to different places, have different conversations, or watch different television programs. Even when there is overlap, our perceptions of the world are uniquely our own.
This idea that each individual person or organism holds a distinct model of the world is called umwelt, a term coined by Jakob von Uexküll in 1909. In a human context, umwelt leads to conversations about philosophy and psychology. With other species, however, umwelt encompasses the unique sensory information that different animals use to navigate their environments.
Take the house cat, one of our most familiar animal companions. Cats inhabit our homes and share our lives, yet their experiences differ from our own. Domestic cats have better senses of smell and hearing than we do, but weaker taste and sight. However, their ability to use their whiskers to sense vibrations and atmospheric changes such as temperature and wind gives them a sensory experience that we lack and can only imagine. A cat’s umwelt is different from ours.
Umwelt is tailored to a species’ habitat and physical environment. For domestic felines, being sensitive to vibrations aids in their wait and pounce hunting strategies—information that we humans don’t need for our own survival.
Cat whiskers are only the tip of the iceberg when it comes to sensory abilities in other species. Birds, sea turtles, and salmon migrate thousands of kilometers and return to specific locations using sensors that detect the Earth’s magnetic field. Other species, such as bumblebees, platypuses, and sharks, sense electrical impulses that they use to catch their prey. And, of course, animals like bats and dolphins are well known for their abilities to use echolocation to “see” their surroundings and their prey through sound.
These sensory abilities help other species adapt to their habitats. Humans don’t need to echolocate because we aren’t catching moths at night or swimming through deep ocean water. Our umwelt is different from that of a bat or a dolphin. We perceive the world differently.
As humans, we sometimes struggle to accept when people are the exception to the rule. Other than humans, most other species can see ultraviolet light. Our inability means that we view seeing ultraviolet light as a special ability, rather than the norm. It has taken a long time for us to accept that we are the ones lacking the skill that most other species possess.
This isn’t the only thing that holds us back from discovering other species’ umwelt. We can’t know what we don’t know. Just as I can’t truly understand what it’s like for you to visit your childhood home, humans can’t fully understand what it’s like for a homing pigeon to know how to find a specific place from miles away or for a cat to tell the weather with its whiskers. As much as the science can tell us about magnetite receptors that guide migrating salmon or photoreceptors to see ultraviolet light, it takes imagination and a leap of faith to understand what that might be like for the animal that possesses that ability.
Our inability to understand extends to the broader environment as well. If we lack the true knowledge of how an animal interacts with its habitat, how can we understand if we disrupt that relationship? We know that if we cut down a forest, that we are destroying habitat. But what if we are changing the environment in ways that we can’t even understand or possess the ability to know about?
Umwelt says that our minds interpret our environment, and therefore they are intrinsically linked. As humans, we rely on our large brains to build skyscrapers and even go into space. Despite all of our abilities, some things are beyond us. Even if we can’t fully understand it, there’s something wonderful in knowing that every species has their own unique way of experiencing the world—even us.
To learn more about umwelt, check out An Immense World by Ed Yong.