Uncovering the Mystery of Camouflage and Color: An International Study Shakes Up Evolution’s Guidelines
Should animals be invisible or shine to scare? That’s the age-old dilemma that evolution has grappled with for millions of years as animals try to evade predators. An international team of scientists, led by Colombian Iliana Medina from the University of Melbourne and British William Allen from Swansea University, decided to test this question on a global scale. The results, published in the journal Science, challenge our previous assumptions: there is no one-size-fits-all visual defense strategy. It all depends on the context.
For the study, researchers placed 15,018 paper butterflies in 21 forests across six continents, each with a real worm as bait. Three color patterns were used: one brown camouflage, one orange and black typical of warning coloration, and another turquoise and black, uncommon in nature. Birds, the main predators, determined the outcome: which butterflies to attack and which to avoid. Scientists measured the frequency of attacks.
The results were clear: there is no universal winning tactic. In areas with high predator competition and low light, camouflage was more effective. Cryptic animals went unnoticed in the shadows. However, in bright habitats with less competition, warning colors worked better. Birds, recognizing orange and black patterns, avoided prey that looked toxic or unpleasant. According to Reboreda, “when predators compete, they become less selective and attack anything visible; that’s where camouflage saves lives.” But over time, predators learn, and that advantage disappears.
The study showed that predators’ previous experience influences as much as light or landscape. Birds that had previously attacked camouflaged prey learned to detect them, reducing their effectiveness. In contrast, warning colors retained their power as long as predators remembered the association between color and bad taste. The turquoise and black pattern, being rare, offered initial protection: predators did not recognize it. But as they learned, they also stopped falling into the trap.
The research team, which included experts from Australia, Spain, Argentina, Colombia, and Costa Rica, plans to expand the experiments by incorporating movement, scent, and more types of predators. Although they used paper butterflies, the global pattern obtained lays the groundwork for understanding how environmental changes—such as deforestation or light pollution—affect the survival strategies of thousands of species.
Evolution does not have a single recipe. In nature, color and camouflage engage in a constant battle, and the winner changes with the landscape, light, and the predator’s memory.
