Camouflage or Warning Colors? Insects Play the Survival Game

A massive global study has now revealed that neither camouflage nor warning colors is the best defense in every situation. Instead, the success of these survival strategies shifts depending on forest light, predator density, and prey populations.

“This is the most comprehensive experimental study on warning signal success that I have ever seen,” says evolutionary biologist David Kikuchi of Oregon State University, who wasn’t part of the research. “It reveals patterns that have been previously hypothesized but not tested.”

To test what really works, researchers led by evolutionary ecologist Iliana Medina Guzman at the University of Melbourne went big, really big. From 2020 to 2022, they ran experiments in 21 forests across six continents, from icy Finland to lush Kenya and Brazil.

The team created more than 15,000 paper “moths”: some with barklike camouflage, some with bold orange-and-black stripes, and others with a funky turquoise-and-black pattern. They attached mealworms (a tasty snack for birds) to the fake moths and left them out in the wild to see which ones got eaten.

The results? No single strategy was foolproof. In areas with fewer predators, bright warning stripes worked better. But in places teeming with hungry birds, camouflage was often the safer bet.

“That fits well with the theory that suggests that when competition is intense, the predators just have to go and eat whatever they can,” Guzman explains. In those cases, flashy colors just made the insects more noticeable—and more likely to become lunch.

One twist surprised even the scientists: the classic orange-and-black pattern worked remarkably well across many ecosystems. “There is often quite strong selection against rather small deviations from local warning signals,” Kikuchi notes. In other words, if a bug dares to stray too far from the local “look” of danger, predators may ignore the signal altogether.

Light levels, surprisingly, didn’t matter much for warning colors. But camouflage struggled in dimmer forests, where shadows blurred patterns and made hiding less effective.

The findings don’t just solve a nature mystery; they highlight how tiny shifts in the environment, like logging or climate change, could shake up insect survival strategies.

Large shifts in light levels caused by activities like logging could significantly alter prey communities. Camouflaged insects might suffer more losses, while brightly colored species might hold their ground.

So the next time you see a bug with stripes, or one that vanishes against a tree trunk, remember: it’s not just fashion. It’s survival, and the best outfit depends entirely on where you’re standing.

For more details, refer to this article published in Science.