Chickens have been domesticated for between 8,000 and 10,000 years, but I’d bet there are still some fascinating facts you don’t know about our feathered friends. Here are 6 of the most surprising things to know about Gallus gallus domesticus, the humble barnyard chicken.
1. Chickens Over Everything
At an estimated population of 25 billion, there are more chickens in the world than any other species of bird. While chickens have been domesticated for thousands of years, they are actually a subspecies of the red junglefowl, a type of pheasant native to Asia.
2. Born For Fighting, Not Food
According to Smithsonian Magazine, there’s strong evidence that chickens were first domesticated for the purpose of cockfighting, not as a food source for humans. Today, cockfighting is frowned upon by much of the world. Louisiana was the last state to ban cockfighting, passing a law outlawing the pastime in 2007. Cockfighting is now illegal in all 50 states, but still commonly practiced in much of South America and Asia.
3. Romance In The Barnyard
Female chickens prefer roosters that “tidbit” frequently. Tidbitting is a behavior in which the male makes a repeated sound (known as a “food call”) as he picks up and drops a piece of food. Roosters perform this behavior to alert the rest of the flock to the presence of food (though hens don’t respond if they already know about the food). Females also prefer roosters with brighter, larger combs on their heads. There’s also evidence that the male’s wattle – the red dangling flesh below his beak – evolved to catch the attention of hens during mating season.
4. A First In Science
The first bird to have its genome sequenced? The common chicken, with the sequencing completed in 2004. Technically, it was the red junglefowl that became the first feathered animal to have its genome sequenced, with the work spearheaded by the International Chicken Genome Sequencing Consortium. According to researchers writing in Nature, the chicken’s genome comes down to “about 1 billion DNA base pairs,” with 1 pair of sex chromosomes and 38 pairs of non-sex chromosomes.
5. Dreaming In Technicolor
Unlike many other animals, chickens see in full color. There’s also some evidence that chickens dream; at the least, they experience rapid eye movement (REM) during sleep, just like humans do.
6. Tough Mothers
Chickens have a complex linguistic repertoire, including 30 distinct vocalizations to announce the presence of a threat. And hens are fierce, defending their chicks from predators at all costs. Another amazing fact, courtesy of PETA,
7. Rejection Is Tough
Female chickens (hens) mate a lot, often copulating with far more males than are necessary to fertilize their eggs. But in a process known as “seminal evacuation,” hens have been shown to reject the seed of certain mates, literally expelling the rooster’s semen after intercourse. This process isn’t random. Scientists have found that hens are actually pretty picky when it comes to their mate; they just choose to discriminate between mates after sex, not beforehand. In fact, researchers have found a correlation between when a hen chooses to eject a rooster’s semen and the rooster’s social status within the group. This is an important mechanism, especially since male rooster’s can “force” mating when they choose to do so.
