Karen Oberhauser, professor emeritus of entomology at the University of Wisconsin-Madison, has been studying monarchs since 1985. She noted the number of monarch butterflies varies widely from year to year driven mostly by weather conditions that have become more extreme due to climate change.
“What we want to do is make the ceiling, or the top of those fluctuations, higher than it has been,” Oberhauser said. “Right now, the population is so low that there’s a chance that, in any given year, a catastrophic event could send monarchs spiraling to a point from which they might not be able to recover.”