More Monarch Butterflies Than Usual Appear to Be Migrating This Fall Every autumn, monarch butterfliesmigrate across the U.S., headingsouth (or west) for the winter. But over the past two decades, their numbershave been declining, to the point that they arebeing considered for the endangered species list. Reports of this year’s migration seem to indicatemore of these winged wonders than usual. This year, observers along the eastern migration route have reported seeing larger numbers ofbutterflies than usual headed south for the winter. The Center for Biological Diversity reported that the population spending the winter in Mexico had increased by 144% since counts were taken in 2018. Some groups note that temperatureand rainfall have both been favorablefor increased egg and larvae survival. If this year’s migration does turn out to belarger than usual, it could be a sign thatconservation efforts are starting to pay off.