Authorities launch plan to save endangered butterflies

Authorities are to temporarily shut one lane of a busy road to protect millions of butterflies on their seasonal migration, officials said yesterday.

Under the measure, one lane of the freeway near Linnei Township (林內鄉) will be closed on the mornings of April 3 to April 5 during the "peak hours" of the yearly migration by purple-spotted butterflies.

coexistence

The measure could lead to traffic jams but it is worth doing, said Lee Thay-ming (李泰明), head of the National Freeway Bureau.

"Human beings need to coexist with the other species even if they are tiny butterflies," Lee said.

About one third of the country's purple-spotted butterflies risk their lives at the end of winter by flying north along the 300km route, which cuts across the elevated road, said Jhan Jia-long (詹家龍) of the Butterfly Conservation Society of Taiwan.

A study of Jhan's group showed that an estimated 11,500 butterflies per minute flew over the freeway in the three hours to noon on April 3, 2005 and that at least one million butterflies flew past the area on that day.

"A number of butterflies perished when they were dragged into strong turbulence caused by cars racing along the freeway," Jhan said.

Professor Sweehu Cheng (鄭瑞富) of I-Shou University, one of the volunteers dedicated to the protection of indigenous butterflies, estimated that many thousands of butterflies were killed on the freeway each spring.

Authorities also erected a protective net along the freeway, hoping that butterflies would be forced to fly at an higher altitude and avoid crashing into cars.

Ultraviolet light

The third measure being taken is to install ultraviolet lights under the elevated road, which experts said could lure the light-sensitive insects to fly safely underneath.

The measures were aimed to reduce the ecological impact from the construction of the freeway, Cheng said, adding that butterflies are also a key link in the country's food chain.

"The factor [protection of butterflies[ was not taken into consideration when the freeway was built," he said. The freeway was inaugurated more than four years ago.

The proposed measures were presented by Cheng and Lin Tieh-hsung (林鐵雄), another professor at I-Shou University.

Cheng said he had not expected the measures, which would cost approximately NT$1 million (US$30,000) to implement, would be approved.

Each winter, millions of purple-spotted butterflies move south beginning in November, with approximately 600,000 wintering in "Purple Butterfly Valley" of Maolin, which along with the Monarch butterfly's winter home in Mexico is one of only two mass wintering sites known in the world, Jhan said.