BENGALURU: Studies have shown that what appear to be bewildering colours in the wild are actually defenses against predators and prey. A global experiment study report published in the research journal Science on Thursday explains the reasons for it.
The field study titled “The evolution and ecology of multiple anti-predator defense”—also published in the Oxford Academic journal- Journal of Evolutionary Biology—states that studies indicate that anti-predator strategy is more effective in helping insects survive potential predatory attacks.
Along with global researchers, the Indian work was conducted by researchers and students from the National Centre for Biological Sciences (NCBS), Bengaluru.
Dr Iliana Medina from the University of Melbourne, Australia, and Dr William Allen from Swansea University, UK, conducted a global experiment on six continents using more than 15,000 artificial prey in three different colour patterns—a classic warning pattern of orange and black, a dull brown that blends in, and a novel, potentially warning bright blue and black pattern.
These artificial prey models are deployed in forest areas across the world, and they found that the natural predators presumably encountered them and decided either to attack and eat or avoid them. Findings of this experiment revealed that when it comes to deterring predators, the ecological context is crucial, and several factors play a part in determining whether a camouflage or warning strategy works best.
“For a long time, scientists wondered why some animals use one defence over the other—and the answer turns out to be complicated. The predator and prey community and habitat are all influential. This helps explain why we see camouflaged and warning-coloured animals all over the world,” Dr Allen said.
The study discovered that the predator community had the biggest impact on which prey colour was most successful against predators. The results supported the notion that when predators compete intensely for food, they are more likely to risk attacking prey that might be dangerous or distasteful. Hence, camouflage worked best in areas with a high predation pressure.
However, being cryptic did not always work.
In bright environments, camouflaged prey was more visible than in darker environments and was attacked more than prey with classic warning colours.
Familiarity with prey using different colour strategies was also important.
In places where cryptic prey was abundant, hiding became less effective, as predators were presumably better at locating camouflaged prey.
Krushnamegh Kunte, Associate Professor and Principal Investigator, Biodiversity Lab, NCBS, said it is a rare insight into how animals, especially insects, which make up a significant proportion of the known species of organisms on earth, evolve such effective anti-predatory strategies over a broad swath of habitats.
Researchers said the findings will now help build a better understanding of the evolution and global distribution of these common, visual anti-predatory strategies in animals.