The rare Taiwan sassafras is the only plant that the Broad-tailed Swallowtail butterfly feeds on.
Think of the last butterfly you saw fluttering around your home or school. Now imagine you never saw that kind of butterfly again. That's happening to butterflies in Taiwan. Already, scientists have identified three known species that are extinct. They include the Juvia Large Crow, Shepherd's Fritillary, and Monarch. Many others are critically endangered. Their populations have become so small, they may not survive many more generations.
The biggest threats to butterflies are humans. Some butterflies like the Purple Crow are threatened because their habitats are being destroyed. Others are threatened when people bring in new or invasive species that don't naturally live in an area. This happened to Cycad Blue butterflies. As caterpillars, they eat plants called Taitung cycads. When people started planting other cycad species in gardens, native cycads were crowded out, putting the Cycad Blue butterflies at risk.
Natural factors also play a role. The Taiwan Beech Hairstreak is rare because the plant it needs to survive, the Taiwan Beech, is also rare. This is also true for the Broad-tailed Swallowtail. This endangered butterfly feeds only on the rare Taiwan sassafras.
In 1989, Taiwan passed the Wildlife Conservation Law to protect rare and endangered wildlife. People use the laws to protect the endangered butterflies and their habitats.