The World Wildlife Foundation recently reports that the number of monarch butterflies overwintering in Mexico has declined drastically. Although extreme drought conditions have dried up nectar plants monarch butterflies rely on for food. The destruction of their overwintering grounds also poses a considerate threat.
When monarch butterflies arrive in Mexico from Canada and the United States, they converge on oyamel fir trees. The trees provide shelter to monarch butterflies they are also essential to the communities that surround the forests. In the past, residents used the wood for cooking and heating, but recently, they have began to sell it in order to support their livelihoods. As a result of logging oyamel fir trees, the habitat of the monarch butterfly population has shrunk.
In 2008, scientists used satellite imagery to illustrate the degradation of oyamel fir forests. Officials from Canada, Mexico and the United States met to quickly develop a monarch butterfly conservation plan. A key feature of the plan focused on protecting the monarch butterflies’ habitat. Mexico agreed to enforce a ban on logging within the Monarch Biosphere Bio Reserve.
Despite various conversation efforts, including paying landowners for logging rights, the monarch butterfly population continues to decline. There was a 28 percent reduction in numbers of butterflies overwintering in Mexico. If further efforts are not made, some scientist predict the total collapse of the ecosystem that supports monarch butterflies in Mexico.
What is the main idea of this passage?
Explanation
Answer [A]: The main idea of this passage is that an increase in logging of the ovamel fir tree has diminished the winter habitat for monarch butterflies, and, consequently, decreased the population of the butterfly. Monarch butterflies do migrate from Canada and the U.S. to Mexico, and increased logging has been brought on by economic need. However, the point of the passage is to make the connection between this increased logging and the decrease in butterfly population.
