Monarch butterflies have it tough. Farmers have eradicated milkweed, the butterflies’ favorite food, and drought and heat are messing with butterfly reproductive cycles. Normally, monarchs migrate in droves from the U.S. down into Mexico for the winter. But surveys showed that last year there were fewer monarch butterflies spending the winter in Mexico than in any year since the surveys began in 1993.
In 2013, butterflies were found in just 0.67 hectares of forest, a 44 percent decrease from 2012. That’s after it had already dropped 59 percent over the previous two years. This is a pretty good indication of butterfly suffering. From the University of Minnesota:
Forest area inhabited by monarchs in Mexico is used as an indirect indicator of the number of butterflies arriving from Canada and the United States each year following a migration of more than 4,000 kilometers. The butterflies spend November through March hibernating in Mexico’s temperate forests.
The problem here isn’t that it’s warm enough for butterflies to stay north. It’s that there are simply fewer butterflies. Pretty soon, that ill-considered tattoo on your ankle will be the only monarch left.
Number of monarch butterflies hibernating in Mexico reaches an all-time low, University of Minnesota.