The Origins of Chicken Domestication

To Find Red Jungle Fowl, it Took a Little Research and a Trip to Asia

The Origins of Chicken Domestication

Out of the 9,000 or 10,000 bird species on this planet, have you ever wondered why chickens were chosen to be our source of food, eggs, entertainment, and companionship? There are at least a thousand birds that are of similar size. Through selective breeding, I bet a few dozen of those could have been bred to lay a surplus of eggs for our consumption. Other birds show elaborate territorial displays that our ancestors could have watched with amusement. But it was the now ubiquitous chicken that they choose to domesticate.

I have heard of people traveling abroad to solely experience the food — pizza in Italy, beer in Germany, and so forth. Some plan their whole trips based on where, when and what they are going to eat. I, on the other hand, choose my recent trip based on the likelihood of seeing a bird. Yes, a bird — a bird that epitomizes our history of keeping poultry. My trip to Khao Yai and Chiang Mai, Thailand, was planned around the chances of seeing the original chicken — the red jungle fowl, Gallus gallus.

True red jungle fowl.
True red jungle fowl.

Archeologists believe that the reason why G. gallus was first domesticated was for the entertainment the cocks provided through their fighting and not as a primary source of food. The effort to domesticate chickens happened most likely 7,000 to 10,000 years ago with multiple attempts. The earliest fossil bones that possibly belong to a chicken were located in northeast China and date to 5,400 B.C. What is remarkable in this finding is that G. gallus never naturally lived in cool dry plains.

At 6 a.m. on a Sunday morning, my friends and I joined a local park ranger as we entered Thailand’s first national park — Khao Yai. The park’s altitude is 400 to 1,000 meters above sea level and has three main seasons: rainy, cold and hot. We were touring the park during the rainy season with the streams at peak flow and the average daily temperature at 80°F. With leach socks pulled knee-high for our three-hour private hike through the forest, we heard helicopter-like hornbills flying overhead, gibbon primates greeting each other and a dozen or so of the 320 native bird species chirping. We spotted wild Asian elephant scat and footprints, and for a brief minute saw a red jungle fowl scratching in the moist soil before she acknowledged us and flew chaotically like her domesticated relatives do so well. These tropical birds are as much a part of a forest as a leopard or a monkey.

A red jungle fowl male.
A red jungle fowl male.

Since red jungle fowl spend most of their time foraging on the forest floor for insects and vegetation and fly only to nest at night, this species became more favorable to Africans, whose comparable native guinea fowl flew off into the forest whenever they pleased. To be fair to the other contributors to our domestic chicken, it should be mentioned that geneticists have identified three closely related species that might have bred with the red jungle fowl to create our modern day chicken.

In 2004 geneticists completed the chicken genome and found that through selective breeding, our ancestors chose birds that had a mutated TSHR gene. In wild animals, the gene is responsible for coordinating reproduction and day length, which make certain animals breed according to specific seasons. So over many generations, our ancestors used this mutation in their favor, which disabled the TSHR gene and allowed our chickens to lay eggs, year round.

A pullet.
A pullet.

Another reason why G. gallus was a good fit for domestication is that the showy males are an athletic runner, jumping at intruding males or predators with their spurs to protect their harem. The rooster’s crows and softer coos also alert his avian family, which our ancestors quickly learned to interpret. Female red jungle fowl, with their brown bodies, help protect their offspring on the forest floor. Their precocial offspring are ready to run and learn from their mom hours after they hatch.

I took a 12-hour train ride from Bangkok to see the mountainous and historic Chiang Mai. There, in northern Thailand, I was lucky to spot several red jungle fowl males, females, and chicks. I saw females caring for their young and pullets and cockerels finding their spot in the pecking order. It was truly astonishing to think that from this wild jungle bird we now have chickens that are cold-hardy, heat-tolerant, child-friendly, broody, all white, all black, and living in our cosmopolitan backyards.

Kenny Coogan, CPBT-KA, is a pet and garden columnist and has authored an ecological themed children’s book titled, “A Tenrec Named Trey (And other odd lettered animals that like to play).” He has a B.S. in animal behavior and is a certified bird trainer through the International Avian Trainers Certification Board. He cares for a 25-year-old Moluccan cockatoo, eight bantam chickens and six Cayuga-mallard hybrid ducks on his homestead. Please search “Critter Companions by Kenny Coogan” on Facebook to learn more.


• Dust bathe regularly

• Fly predominately for roosting at night

• Males exhibit behavior called “tidbitting.” Males pick up and drop food repeatedly with beak, calling females over for treat.

• Generally crepuscular – active during dawn and dusk

• Dominant males crow

• More aggressive then domestic chickens towards potential predators

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