What Is a Chicken’s Umwelt?

Umwelt is a concept developed in 1905 by German biologist Jakob von Uexküll. In German Um means around and Welt means the world. Your umwelt is everything you are able to perceive in the world around you.

What we humans perceive in our surroundings is not the same as what a chicken perceives in the same surroundings. A human and a chicken, together in the same place, therefore don’t experience the environment in exactly the same way.

Understanding a chicken’s umwelt is essential to understanding the chicken’s behavior. So let’s look at some of the ways a chicken perceives its environment.

Sight

Humans basically see the same thing out of both eyes. In contrast, a chicken has a dual eye system. It therefore sees different things out of each eye. The chicken also has greater peripheral vision than a human. But it has much more limited binocular vision, which results in limited depth perception.

Depth perception allows us to judge how far away something is, because it lets us concentrate on things at a certain distance while ignoring anything that’s closer or farther way. To see how this works, hold up a a finger at arm’s length. Focus on the finger, then focus on whatever is behind the finger. Now try to do that with one eye closed. What you see out of the one eye is basically what the chicken would see. That makes it tough to determine, for example, how close a predator might be.

Chickens also have better color vision than humans. They see four wavelengths — red, blue, green, and ultraviolet — where a human sees only the first three. The chicken’s eyes are designed primarily for seeing only during the daytime. Their eyes therefore have many more light receptors than a human’s eye. Light receptors are essential for detecting color. Chickens therefore live in a much more colorful world than we humans do.

Taste

Chickens share some flavor preferences with humans. For instance, we both like salt in moderation, but neither cares for large concentrations of salt. Both avoid bitter flavors.

The chicken has fewer bitter taste receptors than we do, but they may be more fine-tuned than ours. For example, chickens don’t like saccharine (then again, neither do I!), indicating that chickens are more sensitive to saccharine’s underlying bitterness. On the other hand, chickens apparently lack a taste receptor for sweetness.

We don’t know a whole lot about what chickens can and can’t taste. It wasn’t long ago that humans thought chickens couldn’t taste much at all. We now know otherwise. And we know that in some ways chickens perceive flavors differently from the way humans perceive them. But we still have lot to learn about exactly how a chicken determines qualities of taste.

Smell

Chickens have a keen sense of smell that differs markedly from ours. Chickens have the same number of functioning smell receptors as humans. But only about 15% are of the same type. That means chickens can smell things humans can’t smell. And most likely the other way around.

Evidence suggests that the chickens’ sense of smell informs much of their behavior. Odor, for example, allows them to become attached to familiar objects or environments. Predator-related odors elicit a fear response. And odor helps a chicken determine what it will eat and drink. For instance, odor lets the chicken avoid moldy feed and other toxic substances. As with a chicken’s sense of taste, we’re still learning about the chicken’s sense of smell.

Hearing

A chicken’s ears are largely hidden by feathers, but their internal ear structure is quite similar to ours. Sound frequencies the chicken can perceive range from 10 hertz (Hz) to 10,000 Hz, compared to the average healthy human’s range of 20 Hz to 20,000 Hz. While chickens can’t hear the frequencies we hear above 10,000 Hz, they have better sensitivity for frequencies below 64 Hz.

As humans grow older, our hearing weakens. Age-related hearing loss results from damage to the inner ear’s sensory hair cells, which do not regrow. A chicken, too, may suffer hearing loss from such things as loud noises or certain antibiotics. But it’s only temporary, because the chicken’s hair cells regenerate, restoring the chicken’ hearing.

The way a chicken hears partially makes up for its lack of binocular vision. The chicken uses hearing to gauge its distance from the source of a sound. It does so by noting the time lag between the sound’s arrival to one ear before reaching the other ear. A chicken is therefore more sensitive to noises a human might ignore.

Umwelt

Considering all these things together, it seems obvious that chickens don’t perceive the world the same way we do. And it helps explain why chickens get stressed over things that wouldn’t normally bother us.

But, as Neuroscientist David Eagleman notes, “The interesting part is that each organism presumably assumes its umwelt to be the entire objective reality ‘out there.’ Why would any of us stop to think that there is more beyond what we can sense?”

Why, indeed? Well, as Mike Ryan points out in his book A Taste for the Beautiful: “Different animals, [von Uexküll] argued, can live in the same physical location but inhabit different sensory worlds, so much so that they might as well be living on different planets.”

Not even all humans share the same umwelt. But we seem to live on the same planet — at least most of the time. Wouldn’t it be fascinating if, even just for a moment, we could experience whatever planet our chickens live on?