HOKKAIDO, JAPAN—According to a statement released by Hokkaido University, researchers on the island of Hokkaido have found conclusive evidence of chicken breeding in Japan dating to the middle Yayoi period, between the fourth and third centuries B.C. Chickens are thought to have been domesticated in Southeast Asia some 3,500 years ago and then carried around the world, but the time of their introduction to Japan has been unclear. At the ancient settlement of Karako-Kagi, a team of archaeologists led by Masaki Eda unearthed four bones of juvenile phasianids, a family of birds that includes chickens, pheasants, quail, and turkeys. Using radiocarbon dating and collagen peptide mass fingerprinting, the researchers were able to confirm that these bones belonged to immature chickens dating to the fourth century B.C. Eda said that this provides clear evidence for breeding of chickens during the earliest period when they could have been introduced to the Japanese archipelago. Karako-Kagi's status as an important trade hub during the Yayoi period could have played a role in breeding at the site, he added. Read the original scholarly article about this research in Frontiers in Earth Science. To read about 23,000-year-old shell fishhooks found on Okinawa, go to "Japan's Early Anglers."