If you tend to equate the 5 senses of an animal to those of people, you can get things totally wrong. Animal’s senses vary a great deal depending on what type of animal they are. A predator who has to hunt for his meals will generally have a highly developed sense of smell, much more so than humans. For instance, a dog’s sense of smell is fascinating! They can literally break a scent down into individual components. A prey animal might have a more developed sense of sight, being quite adept at detecting motion in extended ranges. Chickens are considered prey animals. Let’s take a look at the development of their 5 senses.
Eyesight. A chicken’s eyesight is incredible! Due to the placement of the eyes on the sides of a chicken’s head, their field of vision is about 310 degrees. Did you know that a chicken can use their eyes independent of one another, focusing on different things at the same time? Wish I could do that! And whereas humans have three cones in their eyes that allow them to see red, blue and green light, chickens have two additional cones. One allows them to see UV light and the other gives them a heightened sense of movement. Chickens can see movement that is almost imperceptible to humans. For example, a fluorescent light to a chicken is like a strobe light to a person. If you have a fluorescent light in your coop, you might want to change it out before you drive your chickens nuts! Last of all, chickens have mono-vision. Their left eye is farsighted, while their right eye is nearsighted. That way they can watch for predators from a distance and still find their food to eat. Watch your free-range chickens sometime and you might notice them tilt their head while they eat. They are watching the sky with one eye and finding food with the other. That’s pretty cool!
Hearing. Similar to ducks and other fowl, a chicken’s hearing is probably the second most important sense, right behind their sight. Even before they hatch, a baby chick will listen to the sounds that it’s mother makes so as to be able to recognize her, come to her calls and respond to her warnings. It’s a matter of survival for them. A chicken’s ears are not the easiest to spot. They are on the sides of their head, behind the eyes and wattles, and are covered by soft feathers that do not interfere with sound. Similar to humans, chickens have an outer ear, middle ear and inner ear. Sound waves in the middle ear make the eardrum vibrate and these vibrations are then transmitted to the cochlea in the inner ear. The inner ear is also important for balance, which is a key factor for birds that fly. An interesting fact, hearing loss in people is often associated with damage done to the sensory hairs in the middle ear. People are not able to grow new hairs to replace the damaged ones, but chickens can. This has led to some studies that may help with hearing loss in humans.There is some talk about chickens enjoying music and that maybe it can help to increase egg production. I have not tried it personally, but I wonder if some loud music would interfere with the warning sounds that they need to be aware of.
Taste. An interesting note or two here, chickens have small hard tongues, they don’t have nearly the number of taste receptors as people and the ones they do have are far back in their mouth. By the time food hits a chicken’s taste buds, they are pretty much committed to swallowing it. As I watch my chickens eat, they scarf food down so fast that I wonder how they can even have time to taste it. You might read a lot about smothering eggs in the nesting box with mustard or hot pepper sauce to discourage the bad habit of egg eating, but because they have such few taste receptors, I don’t think it affects them. I know that when I tried it with my egg eaters, it made no difference at all. The egg eaters still ate them! Like people, chickens do have preferences for food. Scientists are not quite sure exactly what drives a chicken to eat some foods and not others, but a strong sense of taste does not appear to be a major factor. Some think that it might be the color of the food – chickens seem to like red, or motion – a hopping grasshopper will certainly catch a chicken’s eye, or maybe it’s just trial and error. If you watch your chickens eat, you will discover that some chickens seem to devour some foods while others will turn their beaks up at it. Chickens do seem to have an innate ability to know what is good to eat and what is not. If left to their own devices, a free-range chicken will select the food that is nutritious and pass up the stuff that’s bad for them. A fun fact about roosters, they will generally taste food first and if they approve, they will call all their gals over to partake as well, sometimes breaking the food into smaller pieces so everyone will get a share.
Smell. A chicken’s sense of smell is not thought to be a highly developed sense and it is believed that this sense is not as critical as other senses in poultry. Chickens have been known to show preferences or aversions to a wide range of odors, but it is believed that this is more an indication of learned behavior. One odor that chickens can detect is ammonia, which can be very hazardous to the health of chickens. They are able to detect levels lower than what a human can detect and possibly remove themselves from a potentially harmful environment.
Touch. Touch is an important sense, albeit not as critical as sight and hearing. Chickens are able to detect pressure, pain, hot, cold, and limb position with their sense of touch. Have you ever watched a chicken standing in the snow, or even just outside on a cold winter day. They will tuck one foot at a time up into their feathers for warmth. A chicken’s beak is especially sensitive, which is good since they use their beak extensively for touching, feeling and manipulating objects and food. They also use their beaks for preening, building nests and for defense when necessary.
Most of the studies regarding chickens pertain to their sight and hearing, their two most important senses. We have to remember that our chickens are animals and that just because something affects us positively, such as a coat in the winter, does not mean that a winter coat for a chicken is a good thing. Nature has provided them with many defenses, skills, senses and innate abilities to battle the elements, find food, avoid enemies, and raise a new generation of egg layers. So, observe your chickens, interact with them, have fun and enjoy them!
Sources:
http:// https://www.coursera.org/lecture/chickens/smell-and-touch-3K9Tg
http:// https://articles.extension.org/pages/66178/hearing-ability-of-poultry
http:// https://www.humanesociety.org/sites/default/files/docs/about-chickens.pdf