Researchers from Hokkaido University have revealed the earliest clear evidence of chicken domestication in Japan, shedding new light on how this familiar barnyard bird spread across the archipelago. The discovery, described in Frontiers in Earth Sciences, centers on a set of well-preserved bone fragments that demonstrate brood care, a key indicator of sustained chicken rearing rather than opportunistic scavenging by wild relatives. This finding moves the timeline of chicken domestication in East Asia back to a period that aligns with growing long-distance exchange networks and agricultural intensification across the region.
Chickens and their wild kin belong to the broader pheasant family, a diverse group that includes pheasants, turkeys, and quails. The challenge for scientists has always been distinguishing domesticated birds from their wild counterparts in the fossil record, especially in areas where early farming left only sparse traces. In this study, researchers used a precise method to verify chicken identity by examining collagen proteins extracted from the bones with mass spectrometry. The results confirmed that the bones originated from chickens and not from wild pheasants, providing a robust biological signature of domestication in this locale.
The Yayoi period, spanning roughly from 200 BC to 300 AD, is a pivotal era in Japanese history marked by agricultural innovation, trade, and social transformation. The site bearing the chicken bones appears to have functioned as a significant trading post during that time, a hub through which poultry—and possibly other domestic stock—moved into the Japanese archipelago and beyond into neighboring regions. The interpretation is that early farmers kept chickens for food and perhaps for other purposes tied to ritual or social status, and that these birds were part of broader networks that helped disseminate domesticated species across East Asia.
Today, chickens are among the most widespread domestic animals on the planet, with a global population that exceeds 33 billion. The long arc of chicken domestication likely began in Southeast Asia around 3500 years ago, with subsequent waves of migration and cultural exchange carrying domesticated birds to distant shores. This latest research in Japan adds a crucial chapter to that global story, illustrating how a simple domestic animal can illuminate patterns of human movement, settlement, and economic exchange across continents. The findings also invite further work to map the precise routes by which chickens traveled, the roles they played in early farming communities, and how selective breeding might have shaped both meat and egg production in different regional contexts.