Butterflies and Vehicles Don't Mix
Nevada and Taiwan Take Steps to Keep Them Apart
Two species of endangered butterfly, at opposite ends of the earth, get respite from vehicles. One is protected during its migration, the other needs year round relief.
In Nevada, the Sand Mountain Blue Butterfly (Euphilotes pallescens arenamontana) is being given relief from off road vehicles (ORVs) in the Great Basin Desert. And in Taiwan, a portion of a major highway is being closed to cars during the annual migration of their Milkweed Butterfly (Salatura genutia).
Sand Mountain Blue Butterfly Habitat Lost to ORVs
The problem in Nevada has been building over the last 3 years as environmental groups such as Public Employees for Environmental Responsibility (PEER) and the Center for Biological Diversity have pressed to have the endemic butterfly listed as an endangered species. Both the Bureau of Land Management (BLM), which manages the Sand Mountain Recreation Area, and the US Fish and Wildlife Service, which determines what species are listed under the Endangered Species Act, have taken their time responding.
Meanwhile butterfly habitat at Sand Mountain has declined by 50% and what is left is crisscrossed with 200 miles of ORV trails. An estimated 50,000 ORV users visit Sand Mountain,which is only 75 miles from Reno, every year. This is estimated to be a 25% increase in ORVs.
Pressure by the environmental groups has finally caused the BLM to post an Emergency Order to close some of the most critical habitat. If the Sand Mountain Blue Butterfly is listed, there would likely be more closures, something the BLM is hoping to avoid.
Milkweed Butterflies Protected on Migration
In Taiwan, 600 yards of highway are closed and nets are in place to force the Milkweed Butterflies to fly higher, avoiding collisions with cars. Ultraviolet lights will aid the butterflies in finding their way across and overpass.
The National Freeway Bureau has embraced this project enthusiastically, in sharp contrast to the US situation. But then, Taiwan is famous for having over 400 species of butterfly. They are considered a national treasure.
Unfortunately most of Taiwan’s butterfly species are in decline despite the end of butterfly collecting which saw an estimated 10 million butterflies caught every year. Habitat loss and degradation are being blamed as many of Taiwan’s butterflies face possible extinction. Pesticide use and light pollution may also play a role.
Biologists have worked hard to determine the migration path in hopes of protecting the remaining 2 million Milkweed butterflies. Their migration peaks in late March as they travel 180 miles from southern Taiwan to the north to lay their eggs. In November the young will make the return journey to Kaohsuing where they can escape the winter cold.
Read About Other Endangered Butterflies- Checkerspot Butterfly and Monarch Butterfly
Read about a butterfly success story-The El Segundo Blue Butterfly
Photo Credit: Elizabeth L. Paulson
