ArsTechnica:
“Monarch butterflies could disappear from Eastern US within 20 years. As population declines, the prognosis is not encouraging.
In colder climes, signs of spring can lift a heavy weight from a tired, frozen spirit. Trees bud, flowers bloom, and migratory species trickle in to announce the approach of summer. In the US, one of those species is a floppy orange gem: the monarch butterfly. These insects winter in amazingly dense clusters in Mexican forests before making a staggeringly long journey (one that spans multiple generations, in fact) to summer homes to the north.
But in recent years, the population of monarchs that stay east of the Rockies has dropped like a rock. Precise population numbers are difficult to come by, but estimates kept by the US Fish and Wildlife Service show about an 80 percent decline over the last decade.”
