FONT SIZE:
大友府内町跡出土資料からみた中世日本のニワトリの大きさ
江田, 真毅
Permalink : http://hdl.handle.net/2115/87911
JaLCDOI : 10.14943/105602
Abstract
ニワトリ (Gallus domesticus) は東南アジアに生息するセキショクヤケイの一亜種 (G. galhus spadiceus) を主たる祖先とする家禽であり、日本には弥生時代中期に渡来したとされる。その後の日本で利用されたニワトリの品種や大きさに関する知見は文献史学からもたらされている一方、考古学的には報告書などでの散発的な報告に留まり、実態はよくわかっていない。大分県大分市の中世大友府内町跡では 1570～1586年に比定されるニワトリの骨が多数報告されており、その分析から当時のニワトリの大きさについての知見が得られると考えられた。そこで本研究では同遺跡から出土したニワトリの足根中足骨を計測し、U検定や混合分析 (Mixture analysis) などの統計学的手法を用いて検討した。また、骨の長さを動物園などで飼育されていたセキショクヤケイと比べるとともに、回帰分析を利用してさまざまな品種のニワトリの体重とも比較した。その結果、大友府内町で利用されたニワトリは、動物園などで飼育されていたセキショクヤケイに比べて大きいことが分かった。また、距突起の有無で性を推定して実施した混合分析の結果、雌雄ともに2つの品種あるいはそれに類するサイズグループに由来する個体が含まれることが確認された。雌雄で推定された2つのサイズグループは、いずれも中世末に日本にいたとされる現在の地鶏や小国よりかなり大きかった。このことは、かつての地鶏や小国が現在より大型であった可能性や、これまで文献史料から考えられてきた以上に当時までに外来鶏が普及しており日本鶏と交雑していた可能性から説明できると考えられた。
The common chicken, Gallus domesticus, is a poultry whose main ancestor is a subspecies of red junglefowl (G. g. Spadiceus) that inhabits Southeast Asia, and is believed to have been introduced into Japan in the middle of the Yayoi period. While information regarding the variety and size of chickens used in Japan after the Yayoi period has been gleaned from historical evidence, zooarchaeological studies have been limited, and the actual situation is not well understood. At the medieval Otomo-Funai site (Oita City), many chicken bones dated from AD 1570 to 1586, were found, which could provide insight into the size of chickens at that time. In this study, I measured the chicken tarsometatarsi excavated from the site and performed statistical analysis such as U-test and mixture analysis. In addition, the lengths of these bones were compared with those of modern captive red junglefowl and the weight of various chicken races via regression analysis. The results indicated that the chickens exploited in Otomo-Funai were larger than the captive red junglefowl. The mixture analysis estimated that both males and females included individuals derived from two size groups. The two estimated size groups for males and females were larger than the modern Jidori (Japanese native chicken) and Shokoku that were believed to exist in Japan at the end of the Middle Age. This may be because the former Jidori and Shokoku were larger than they are now, and/or foreign chickens were more widespread and crossed with local chickens more extensively than previously inferred from historical evidence.
The common chicken, Gallus domesticus, is a poultry whose main ancestor is a subspecies of red junglefowl (G. g. Spadiceus) that inhabits Southeast Asia, and is believed to have been introduced into Japan in the middle of the Yayoi period. While information regarding the variety and size of chickens used in Japan after the Yayoi period has been gleaned from historical evidence, zooarchaeological studies have been limited, and the actual situation is not well understood. At the medieval Otomo-Funai site (Oita City), many chicken bones dated from AD 1570 to 1586, were found, which could provide insight into the size of chickens at that time. In this study, I measured the chicken tarsometatarsi excavated from the site and performed statistical analysis such as U-test and mixture analysis. In addition, the lengths of these bones were compared with those of modern captive red junglefowl and the weight of various chicken races via regression analysis. The results indicated that the chickens exploited in Otomo-Funai were larger than the captive red junglefowl. The mixture analysis estimated that both males and females included individuals derived from two size groups. The two estimated size groups for males and females were larger than the modern Jidori (Japanese native chicken) and Shokoku that were believed to exist in Japan at the end of the Middle Age. This may be because the former Jidori and Shokoku were larger than they are now, and/or foreign chickens were more widespread and crossed with local chickens more extensively than previously inferred from historical evidence.
FULL TEXT:PDF