Recently, however, the number of yellow butterflies has dropped to only about 100,000. The reason is mainly a change in the environment of the Yellow Butterfly Valley. Its tourists and businessmen that destroy the Yellow Butterfly Valley,' said Hui-Chi bitterly. Tourists have left trash that pollutes the river and the valley. Businessmen has chopped down huge numbers of the Indian chestnut trees in the valley and replaced them with more "profitable" orchards. The agricultural pesticide used for the orchards also pollutes the land and the rivers. The caterpillars are left without food. The water that the larvae need has been polluted. The Yellow Butterfly Valley is no longer paradise for yellow butterflies.
What's more, several years ago, the government planned to build a dam at the mouth of the Yellow Butterfly Valley in order to meet the growing water demands of southern Taiwan. To build the dam, many trees would have had to be chopped down, and the rivers that run across the valley would have been blocked off, totally changing the ecosystem in the Yellow Butterfly Valley.
