Monarch butterflies are beautiful creatures to watch, but it turns out your backyard lights may actually be confusing their senses. New research by a team at the University of Cincinnati has found that exposure to porch lights or even the glow of your cellphone can disorient monarch butterflies — making their internal GPS system go haywire.
“We found that even with a single work light that you find at a construction site, monarch butterflies treat that like it’s the sun,” says Patrick Guerra, a UC professor and co-author of the study, in a university release.
Artificial light at night messes with a butterfly’s circadian rhythm and the processes involved in when to take flight and when to rest. Monarch butterflies rely on specific proteins that fine-tune their internal compass and tell which direction to fly to the south and how to return. Nighttime light pollution could pose some risk to their annual migration from Canada to Mexico, where they spend the winter.