/ 23 March 2007

Taiwan to block highway for butterfly migration

Taiwan will cordon off part of a highway to facilitate the annual migration of the purple butterfly, whose immigration is compared to that of the monarch butterfly in Mexico, an official said on Friday.

From March 26 to April 6, highway authorities are scheduled to close off the outer lanes of the Number Three highway in west Taiwan, to prevent the butterflies from being hit and killed by passing cars when they fly over the highway during their south-north migration, Taiwan Highway Bureau director Lee Tai-ming told reporters.

The bureau is also to erect mess nets on the side of the highway to make the purple butterflies fly higher when they cross the highway, and to install ultraviolet lights to guide them to cross the highway under a highway bridge.

This is the first time the Taiwanese government has taken steps to protect the migration of the purple butterfly, which is found only in Taiwan and whose annual migration has puzzled scientists.

”This is very necessary, because after spending the winter in the mountain valley, the purple butterflies are thin and weak, and can be easily killed by passing cars,” said Chan Chia-long, head of the Taiwan Butterfly Conservation Society.

The purple butterfly has purple-brown wings, ringed and covered with white dots. Like the monarch butterfly in Mexico they feed on milkweed, and are also known as milkweed butterflies.

Every year, purple butterflies migrate from the north to the south to spend the cold winter in a valley, and fly back to north Taiwan in late March or early April, covering nearly 400km.

At the height of the migration, along the migration route, one can see up to 10 000 purple butterflies flying overhead.

Taiwan is called the ”Kingdom of Butterflies”, home to more than 400 species of butterflies. Forty of them can be found only in Taiwan. — Sapa-dpa