The History of the Domestication of Chickens

Domestic chickens, scientifically called gallus gallus domesticus, can be found all over the world, being a familiar source of meat and eggs. Many scholars agree that chickens were first domesticated from the wild red junglefowl, a bird that can still be found in most of Southeast Asia, and most likely hybridized with the gray jungle fowl.

However, recent research suggests that chicken domestication has multiple origins, particularly in the areas of South and Southeast Asia, China, Thailand, Burma, and India.


When Did the Domestication of Chickens Begin?

Scientists have long debated where the domesticated chicken originated, with India, Southeast Asia, and Northern China having been proposed as places of chicken origin. Living domestic chickens couldn’t be used to narrow down the time window for chicken domestication as doing so requires a type of paleontology based on DNA sequencing.

Genes that researchers have used to date modern chicken only appeared in domesticated chickens in the last millennia or so. 

Two new studies were recently published, precisely pinpointing the origins of domesticated chicken.

A study published in the Proceedings of the National Academy of Sciences (PNAS) found that the earliest chicken domestication began in dry rice fields planted by farmers in Southeast Asia 3,500 years ago. Researchers reevaluated the dates and records of chicken bones from 600 archaeological sites around the world. The earliest chicken remains were found at Neolithic Ban Non Wat, in Central Thailand, a dry rice farming site.

Bronze age sites also revealed remains of early chickens from 1650 B.C.E and 1250 B.C.E. Instead of being flooded like paddies, rice fields were soaked by seasonal rains and attracted hungry wild jungle fowl. Additionally, research suggests that there’s a correlation between the spread of dry rice farming, millet, and other grains with the spread of chicken bones across Asia, the Middle East, and Africa. 

Contrary to the study published in the Proceedings of the National Academy of Sciences, the second study, published in Antiquity, found that domesticated chickens arrived in Mediterranean Europe around 2,800 years ago using the routes by early Greek and Phoenician maritime traders, and then appeared in Africa 1,100 to 800 years ago. Using radiocarbon dating, the researchers found that 23 chicken bones from sites in Eurasia and Africa were younger than previously thought. 

The chicken bones were first incorrectly dated based on the depth of the sediment they were found in. This is because the chicken bones settled into lower sediment layers over time and ended up with other items made by humans. Domestic chicken remains were found in an Etruscan site dated 2,800 years ago and may be when chickens arrived in Europe. 

Additional dating results indicate that it took almost 1,000 years before the chicken spread to the colder climates of Scotland, Ireland, Scandinavia, and Iceland. 

“This comprehensive re-evaluation of chickens firstly demonstrates how wrong our understanding of the time and place of chicken domestication was. And even more excitingly, we show how the arrival of dry rice farming and cereal cultivation acted as a catalyst for both the chicken domestication process and its global dispersal,” said Professor Greger Larson, one of the researchers involved in the studies.

Research suggests that there was a clear domestic relationship between people and chickens, as humans were buried with the chicken remains rather than discarded as scraps.

As the partial or whole skeletons of adult chickens were buried with humans, it suggests that they had a cultural or social significance and were sacred creatures instead of a food source, meaning that a desire for meat did not drive chicken domestication. Additionally, several of the earliest chickens during the Iron Age were also buried alone.

Aside from those two studies, another point in contention on where the chicken domestication process began points to China. Prior to the dates from Southeast Asia, several studies published in 2014 supported the claims that the earliest chickens were domesticated in Northern and Central China. However, the results of the studies were deemed to be controversial. 

In 2016, a study by Chinese bioanthropologists found that out of 280 bird bones reported as chicken from Bronze Age sites in Central and Northern China, only a handful of them could securely be identified as chicken.

In 2016, Joris Peters, a German archaeologist, looked at environmental proxies in addition to other research and found that the habitats conducive to the red jungle fowl were simply not present enough in early China for the domestication process to have taken place.

The researchers suggested that wild jungle fowl were a rare occurrence in Northern and Central China and thus probably an import from Southern China or Southeast Asia where evidence of domesticated fowl is stronger. Based on those findings, a northern Chinese chicken domestication event separate from that of Southern China and Southeast Asia does not seem likely.


Did Humans Consume Chickens Back in the Day?

Archaeological evidence indicates that dry rice agriculture acted as a catalyst for the global dispersal of domestic chickens but according to researchers, human societies did not view chickens as food. In the archaeological sites in Southeast Asia, chicken remains were placed in human graves. During the Iron Age in Europe, chickens were buried alone or in human graves. 

There were no signs of the chickens having been butchered, suggesting that the chickens had some sort of social or cultural significance. 

It was during the expansion of the Roman Empire around 2,000 years ago which prompted more widespread consumption of chickens and eggs. In England, domestic chickens were not eaten regularly until 1,700 years ago, primarily at Roman Empire-influenced urban and military sites. About 700 to 800 years elapsed between chicken’s introduction in England and its acceptance as food.


Who First Domesticated Chickens?

Similar to the cases of pinpointing exactly where the domesticated chickens came from, the subject of who initialized the chicken domestication process is highly debated among researchers. 

Based on the studies that were recently published, rice cultivation played a significant role in who first domesticated chickens. Dry rice farmers in Southeast Asia, particularly in Central Thailand, were the first to domesticate the red jungle fowl.

Dry rice farming in Central Thailand meant that fields were soaked by seasonal rains which then attracted hungry wild red jungle fowl. The red jungle fowl increasingly fed on rice grains and probably grains of another cereal crop called millet.

Did Native Americans Domesticate Chickens?

Contrary to popular belief, Native Americans did not domesticate chickens. In 2007, American archaeologist Alice Storey and colleagues identified chicken bones at El-Arenal 1 on Chile’s coast, in a context dated well before the 16th-century medieval Spanish colonization, ca. 1321–1407 cal CE.

The discovery is considered evidence of pre-Columbian contact with South America by Polynesian sailors, but that is still a somewhat controversial notion in American archaeology.

DNA studies, however, provided support that chicken bones from el-Arenal contained a haplogroup which has been identified at Easter Island, which was founded by Polynesians around 1200 CE. The DNA cluster identified Polynesian chickens, and Portuguese geneticists found this as key evidence to support the pre-Columbian presence of Polynesian chickens on the coast of South America.

Therefore, it seems likely that pre-Columbian chickens were brought in by Polynesian sailors.


What Did Chickens Look Like Before They Were Domesticated?

Regardless of the global dispersal of chickens and where they were first domesticated, domestic breeds of chickens can look very different from their ancestors.

The gallus domesticus or the domestic chicken is debated to have multiple maternal origins but the majority of studies have the consensus that the red junglefowl is its wild ancestor. It was biologist Charles Darwin who first proposed that chickens may have descended from the red junglefowl among other jungle fowl subspecies because of their similar appearances.

Red junglefowl primarily live in areas with lots of scrub, secondary forest, and mangroves. Compared to modern chickens, red junglefowl have a lifespan of approximately 10 to 30 years and are smaller in body mass. 

However, because of DNA studies and radiocarbon dating, results showed that red junglefowl lack the gene for yellow skin and shanks of chickens. Due to this, it is believed that at some point, hybridization of the wild ancestor of chickens with grey junglefowl of South Asia occurred. The body structure of the Indian Gamebird from South Asia and the Brahmas of China gives physical evidence of grey junglefowl influence. 

There is also evidence of genetic contributions of another bird from South Asia, the Sri Lanka Junglefowl, seen on the tail of chickens. There’s also no doubt that the green junglefowl has also contributed to modern chicken breeds.

Over the years, chickens have also acquired diverse genetic characteristics of domestic animals that have facilitated adaptation to different challenging conditions in diverse locations, such as heat stress, humidity, and disease. Compared to other chickens, domestic chickens are also less active and less social. They also produce larger eggs, which are beneficial to the poultry industry.

Unfortunately, in modern times, the red junglefowl population in the wild is decreasing, partly due to habitat loss and partly due to hybridization with feral domesticated chicken breeds.


Final Note

Chickens are one the most ubiquitous domesticated animals around, primarily bred for meat production and egg production. Scholars and researchers have agreed that the earliest chickens were domesticated from the red jungle fowl.  

The geographic origins of domestic chickens or Gallus gallus domesticus have long puzzled researchers as living chickens couldn’t be used to narrow down the time of domestication because it requires a type of paleontology based on DNA sequencing, and the genes that researchers have used to date modern chickens only appeared in domestic chicken populations in the last millennia or so.

However, new research has emerged, shedding light on the history of domestic fowl. Using radiocarbon dating, researchers have determined that the early presence of domestic chickens can be traced to Ban Non Wat in Central Thailand. Dry rice agriculture acted as a catalyst in domesticating chickens in Thailand, with fields attracting red junglefowl. 

Chicken spread across the world, following trade routes and the Silk Road. First, chickens were transported across Asia and then through the Mediterranean along routes used by early Greek Etruscan and Phoenician maritime traders. Chickens then arrived in Europe around 800 BC, and it took almost 1,000 years before chickens made their way to the colder climates of Scotland, Iceland, and other areas. 

Professor Greger Larson, a researcher involved in the studies, stated that the re-evaluation of chickens firstly demonstrates how humans misunderstood the time and place of chicken domestication and it is exciting to trace the origins of the gallus domesticus and how they spread over the world.