Rare butterflies appear on Yilan's Taiping Mountain
By Y.F. Low, CNA
May 15, 2009, 4:46 pm TWN
TAIPEI, Taiwan -- Broad-tailed swallowtail butterflies, an endangered species endemic to Taiwan, have recently made rare appearances on Taiping Mountain in the northeastern county of Yilan, forestry authorities said Friday.
Even greater excitement was generated, however, when nature photographer Lin Chieh-sheng managed to capture an image of one ofthe butterflies May 9 -- a rare shot, as broad-tailed swallowtails usually fly high between the trees and seldom present an opportunity for a photograph, according to Lin.
Lin's search for the broad-tailed swallowtails was made in cooperation between himself and the Luodong Forest District Office under the Council of Agriculture's (COA's) Forestry Bureau.
"During the 11-day search, we managed to find the butterflies only three times," Lin said.
Broad-tailed swallowtail butterflies are usually seen between May and June every year. As the larvae of the butterflies feed on Taiwanese sassafras leaves, the insects usually appear in Taiwanese sassafras forests at elevations of 1,000 meters to 2,000 meters in central and northern Taiwan, according to forestry officials.
However, there are not many Taiwanese sassafras trees left, which means that the butterflies are also few and far between, prompting the COA to declare it an endangered species in 1989.
The species was first discovered in Taiwan in 1932 by Japanese entomologists near Duli Mountain in Yilan's Datong township, the officials said.
Its most distinguishing characteristic is its extraordinarily broad, red swallowtail.
The butterflies' forewings are blackish-brown in color, and their hind winds bear a large, white spot in their central discals and surrounding areas, with a series of red, crescent-shaped markings on the outer margins of the wings.