It is a warm and humid morning in mid-August and not yet light. Wakefulness is coming to me this morning before the sun, and I open my eyes to look around the room, lit only by alarm clock glow. A slight breeze blows through the open windows and all is quiet. The nights sounds of owls and coyotes have ceased and the birds have not yet started their songs of daybreak.
Then I hear the first morning sound floating up the hill, “Err-err-eeeeeerrrrr!” Emile is awake. “Err-err-eeeerrrrr!” In a bit Emile’s call is joined by another one, a bit flatter and raspier, “Err-err-Rup! Err-err-Rup!” Snowball has added his morning commentary. This duet continues for a while and then is joined by another voice, more shrill and abrupt, “Errrrr-errrrrr!” Now Paul is chiming in. I swing my legs over the side of the bed and start my day—the sun is just beginning to lighten the eastern horizon.
By the time I get to the coop, the sun is peaking over the eastern edge of the world. Some of the hens are off the roost and scratching around the coop. The boys are all still on the roost and are continuing their song. I open the coop doors and everybody hurries outside, and the roosters carry their message to the great, wide world.
Everybody knows that roosters crow in the morning and most people also realize that roosters also crow other times during the day. But not very many people wonder why. What is their motivation? Here’s the good news: There are real scientists out there who wonder why roosters crow. They think about that as well as other chicken behavior and study chickens in controlled scientific experiments. One such scientist is Tsuyoshi Shimmura at Nagoya University in Japan. Dr. Shimmura and his colleagues have tackled interesting topics such as “Do chickens raised by a broody hen behave differently than chickens raised without a mom?” (Short answer: “Yes!”) and “Do chickens in small cages peck more than free-range chickens?” (Long answer: The amount of “beak related activity” (e.g. grazing, eating, drinking, preening, aggressive pecking, gentle feather pecking, severe feather pecking, litter pecking, and object pecking) stayed about the same regardless of how chickens were housed, but which type of beak related activity is influenced by their housing).
So, what about crowing? It turns out that “Err err errrrrr” means a bunch of different things in rooster lingo. (And let’s face reality! “Err err errrrr” is what roosters really say. Has anybody, anywhere, ever heard a rooster say, “Cock-a-doodle-doo? Come on, people!) According to Dr. Shimmura, Emile’s “Err err errrrr” can mean any of the following:
Territory: “Good morning, everybody! I’m Emile, you are my flock, and I’m in charge!”
Warning: “Here comes Randy with the scary garden cart! Have no fear girls! Gather round and I shall protect you!”
Pecking Order: “Hey, Paul, little buddy! You stay in line, or you’ll feel the wrath of my spurs, Okay?” And, Snowball? Just sayin’, you’re lucky there’s a fence between us!”
Food Availability: “Look, everybody! Here’s Randy with the bucket of scratch grain! Feel free to thank me now!”
In other words, roosters crow for pretty much any reason imaginable. But they do seem to crow more in the morning. Scientists always assumed that the rising sun somehow stimulated roosters to crow. But there are a lot of people who have spent time around chickens and are aware that roosters usually crow before dawn. So what’s up with that? Are roosters responding to the increased levels of light, or do they have some sort of internal biological clock?
To find out, the Nagoya University scientists put roosters in an artificially lighted environment that was light for twelve hours and dark for twelve hours each day. As I could have predicted, the roosters started crowing two hours before the lights switched on each day. The timing of their morning crowing was regulated by their own biorhythms! To further confirm the presence of internal biological clocks, the researchers put roosters into a completely dark environment for a period of days. They soon settled into a pattern of a 23.8-hour-day—and would crow at exactly the same time each day on that cycle. When the roosters were subjected to scary lights and sounds, they did respond to them by crowing, but they would always crow more if these stimuli were presented at their “dawn”. The researchers concluded that “internal clocks take precedence over external cues.”
In another study, Dr. Shimmura’s team determined the pecking order in a group of roosters and then observed the order of their crowing. Consistently, the dominant rooster would start crowing shortly before dawn. Then and only then, the second ranked rooster would crow. After he crowed, the third ranked rooster would crow, and like dominoes the other subordinate roosters would commence crowing, one after the other in descending order of rank. When the dominant rooster was removed, the second-ranked rooster jumped right in and started crowing before dawn to start the cascade of the subordinate rooster crowing.
So now we know! Isn’t science great?! Next, I’m hoping this group of scientists will get to work solving that age-old conundrum: “Why did the chicken cross the road?”
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