Taiwan's
butterflies have yet to attract the kind of international attention
the island's birds now enjoy. But just as birdwatchers come to seek
out species seen nowhere else in the world, butterfly enthusiasts who
arrive at the right time of year can see a remarkable natural
phenomenon: The annual 250km migration of purple crow butterflies
(紫斑蝶).
To the
untrained eye, Taiwan’s four Purple Crow species are hard to tell
apart. Wingspans range from 60mm to 75mm. All four appear dark brown
when stationary, but eye-catching patches of blue and purple become
visible when they open their wings.
Researchers
and volunteers are working hard to better understand the lepidopteran
treasures that flutter in Taiwan's fields and forests. Travel
in Taiwan
recently met up with some of these dedicated individuals for a
whistle-stop tour of two purple-crow hot spots – Linnei in Yunlin
County (雲林縣林內鄉)
and Kaohsiung City's Maolin District (高雄市茂林區).
Approaching
Linnei by train, it's the hills inland of the railway line which grab
your attention, and we soon learn that topography is one reason why
this little township is a bottleneck along the purple crows' migration
route. Prevailing winds and the availability of food also influence
when and where the butterflies move, but in recent years a stretch of
National Freeway No. 3 in Linnei has become famous for the vast number of purple
crows (sometimes 500 to 1,000 per minute) who fly over it early each
spring. In 2007 - in a move reported by the BBC, National Geographic
Channel and other global media - the authorities closed one lane of
the freeway and erected 4m-high fencing along one side in an effort
to cut the number of butterfly road casualties...
The complete article is in the May/June issue of Travel in Taiwan magazine.