The Clucking Hen
Hens cluck a lot. The sound is neither the low-pitch sound of contentment, nor the high-pitch sound of alarm. Rather, the sound made by a clucking hen is smack dab in the middle of the chickens’ pitch range, emphasizing neither extreme mood.
Anatomy of a Cluck
The cluck goes up and down in pitch. When analyzed on an audio spectrograph — a machine that makes a picture of a sound — the cluck appears like an upside-down V.
The cluck’s pitch quickly increases to a high point then goes down again. It’s similar to a dog’s bark, a song sparrow’s chip, or you, when you say. “Wow!”
Could this similarity in structure — the making of sounds that quickly rise and fall in pitch — be how we know what a chicken is saying? You bet.
Think of all the situations in which hens cluck (or dogs bark, or you say, “Wow!”). In all three cases, the individual making the sound perceives something of interest. But it’s not something to run away from, or run toward, or attack without further consideration.
That something may also be of interest to other chickens. So communicating about it causes them to respond. The response might be equivalent to a person saying “I hear you,” when you try to get their attention. But the clucking hen could also grab the attention of a predator.
A Revised Cluck
A predator that elicits a cluck is probably not too dangerous. A truly dangerous predator elicits a stronger sound.
Even then, the call elicited by predators varies. For instance, a chicken is more frightened of a flying predator than of a ground predator. So the call announcing an aerial predator is higher in pitch and more whistle-like than the call announcing a ground predator.
A dog’s bark varies, too. A dog might bark from behind the door when its owner slams a car door shut or when a delivery person does the same.
Further consideration changes the dog’s communication from a bark to a whine when he sees the owner. But it changes to a growl if instead he sees a delivery person. Ask any UPS driver.
Chickens growl, too. Consider the broody growl — the harsh sound made by a hen interrupted while on the nest. Or by a low-ranking hen on being approached by a higher-ranking hen. Or by any hen on seeing a small, familiar animal such as a cat or rat slinking through the yard.
Like the dog’s growl, the chicken’s growl is not particularly loud. It indicates defensiveness and mistrustfulness, and serves as a warning to the intruder to back off.
While growling, the hen puffs up her feathers to make herself look bigger. The harsh sound and larger size combine to make the hen appear more formidable than she actually is. Unlike the neutral cluck, the low harsh sound of a growl is a sign of aggression.
Cheeping Chicks
Baby chicks cheep because they’re too small to cluck. Still, they have to deal with competition from their brood mates. They also need to communicate problems to the mother hen. They do so through the use of sounds that reflect their emotions.
We understand them because we use the same conventions to impart emotions to our words. Pleasure sounds begin low and rise, then end. They might also go up and down like a chevron
Peeps that start high and go lower denote distress. High intensity distress calls have a whining quality caused by a longer high-pitch part before the pitch falls. A terrified chick emits a high-pitch shriek.
When a Cluck Becomes a Shriek
Why would a frightened chicken make a harsh sound like a shriek or distress squawk? Based on the conventions of human communication — in which an individual’s motivation to make a sound determines the sound’s structure — you might, instead, expect a whistle-like high-pitch sound to depict the bird’s state of fright.
Loudness is not a problem, because a shrieking chicken might well be in the claws or jaws of a predator, when whispering for help is not an option. But the motivational-structure convention suggests the call is also directed at the predator. The sudden loud shriek might indeed startle the predator enough to drop its prize.
The harsh quality also suggests that the victim will fight to the death. It’s the cornered rat syndrome. Not unsurprisingly, a cornered rat shrieks, too. A sound both harsh and rising in pitch symbolizes the chicken’s emotions quite well.
On the other hand, a hiss given by a setting hen when threatened is a sound, too, but it doesn’t come from the hen’s voice box (syrinx). Were she to use her voice box, she might produce a shriek if her emotion fit the high-fear high-aggression combination. But this sound probably wouldn’t do her any good under the circumstances.
So, when a threatened hen must defend her cherished nest but would rather get away to save her life, she chooses to hiss. The hissing sound masks the emotion that would have been expressed by her voice box, had she used it.
Food Call
A clucking hen, upon encountering some tasty tidbit, might segue from clucking to the tuck- tuck-tuck food call, which brings her chicks running. Once in a great while, a hen without chicks, or a chick itself, will make this sound.
A cock also utters a similar food call to bring hens closer. He might make a less excited-sounding food call on encountering feathers, leaves, or other debris in the yard.
The food call is essentially a quickly uttered and higher pitched variation of the cluck. These qualities — higher pitch in particular — give it a special meaning and attractiveness by making the food-caller seem smaller and, above all, non-confrontational. A future blog will explore the food call in greater detail.
Despite the chickens’ millennia-long association with humans, we’re still learning about the depths of their communication system. Doing so helps us understand the clucking of a hen and other chicken sounds in the same way chickens understand each other.
This blog was written in collaboration with ornithologist Gene Morton, author of Animal Vocal Communication. Gene also co-blogged Do Chickens Mean What They Say?, among others.