In late September, monarchs were apparently carried westward en masse all the way to Colorado by persistent east winds across the Midwest. Now these butterflies seem to be arriving in New Mexico. This unsual westward drift raises interesting questions about how the wind affects migration. Do monarchs use the wind opportuntistically, and zigzag their way to Mexico? Do they wait for winds to provide a direct flight — but are sometimes blown off-course?

"It is very exciting to be a part of this! On Monday night we estimated 500 monarchs roosting here and maybe twice that number the next night," wrote Gloria Jones from Hillburn City, New Mexico.