A large butterfly found in mainland China was confirmed to have migrated 1,600 km from Japan, a Japanese researcher said Friday.

It is the first confirmed migration of a chestnut tiger butterfly, whose scientific name is Parantica sita, from Japan to China, said Hisashi Fujii, a lecturer at Kyoto Gakuen University.

In October 2006, a chestnut tiger marked with letters and figures on its wings was found in the city of Pingfu, Zhejiang Province, near Shanghai, Fujii said.

Later studies by a team of researchers from Japan and Taiwan confirmed it was the same marked butterfly as one released into the wild in August that year in Wajima, Ishikawa Prefecture, along the Sea of Japan coast.

Found in many parts of East Asia, chestnut tiger butterflies are known for making long-distance migrations.

They migrate south from fall to winter, but it is still unknown where they spend winters.

Fujii, 49, leader of the Japan Butterfly Conservation Society, said he believes China provides the main wintering spots for chestnut tiger butterflies.