Chestnut Tiger Butterfly
The chestnut tiger butterfly (Parantica sita) is named for the bold brown, black, and white patterns on its wings, which span around 10 centimeters. It is unique among butterflies found in Japan in that it migrates seasonally, sometimes traveling well over 2,000 kilometers. Why it does this is still unknown. If you happen to spot a chestnut tiger here, you can actually help scientists track its migration and perhaps solve this mystery.
Each spring (April–May) the chestnut tiger travels northeast up the Japanese archipelago to the Tohoku region. During that migration, they can be seen flying from Naruto across to Awaji Island, along the same path as the Onaruto Bridge. Come fall, the chestnut tiger migrates in the opposite direction: however, since the species’ lifespan is just six months (longer than that of most other butterflies), it is the offspring of the spring migrants that make the journey back. Again passing through Naruto, these returnees travel not only to Japan’s Kagoshima and Okinawa, but sometimes as far southwest as Taiwan and Hong Kong (the latter being some 2,500 kilometers from mainland Japan).
