Two dead butterflies found on the freeway near central Linei township. Taiwan is to temporarily block a lane of the road to protect the migrating insects.
Credit: AFP
TAIPEI: Taiwan will temporarily shut one lane of a busy road to protect millions of migrating butterflies.
One lane of a freeway near Linei township in central Taiwan will be closed on the mornings of 3 to 5 April to coincide with the "peak hours" of the annual migration by purple-spotted butterflies.
Though the measure may lead to traffic jams, it is still worthwhile, said Lee Thay-ming, head of the National Freeway Bureau."Human beings need to coexist with the other species, even if they are tiny butterflies."
About one third of the island's purple-spotted butterflies risk their lives at the end of winter by flying north along the 300 km route, which cuts across the elevated road, said Jhan Jia-long of the Butterfly Conservation Society of Taiwan.
According Jhan's observations, an estimated 11,500 butterflies flew over the freeway per minute in the three hours up to noon on 3 April 2005, and at least one million butterflies in total flew past during the whole day, he said.
"A number of butterflies perished when they were dragged into strong turbulence caused by cars racing along the freeway," Jhan said.
Many thousands of butterflies are killed on the freeway each spring, agreed Sweehu Cheng, a professor at Taiwan's I-Shou University who is dedicated to the protection of indigenous butterflies.
Authorities have also erected a protective net along the freeway to divert butterflies out of the path of cars and rigged ultraviolet lights - to which butterflies are sensitive - under the elevated road in a further attempt to lure them safely underneath and away from traffic.
The measures are aimed at reducing the ecological impact of the road, as the butterfly migration was not taken into consideration when the freeway was built four years ago, said Cheng.
Cheng was part of the I-Shou University team that proposed the conservation measures, estimated to cost around AUS$38,000 (one million Taiwan dollars) – but he never expected them to be accepted, he said.
Each winter, millions of purple-spotted butterflies move south beginning in November, with around 600,000 wintering in the 'Purple Butterfly Valley' of Maolin.
Along with the Monarch butterfly's winter home in Mexico, Maolin is one of only two butterfly mass wintering sites known in the world.
