Can you spot the beetle hiding in plain sight? Scientists find new camouflage technique

Sarah Knapton
The jewel beetle uses its shiny carapace to confuse predators  - Bristol University 

Brightly coloured beetles are not just gaudy to attract a mate, but their shiny surfaces actually work as camouflage to deter predators, a new study has shown. 

While male peacocks display colourful feathers to show off, and monarch butterflies use their wings to signal predators they carry a toxin, researchers have found that the gleaming, metallic wings of jewel beetles have a different purpose altogether, concealment.

In a counter-intuitive finding, instead of making them conspicuous, the researchers say the insect's iridescent wings act as a form of camouflage, allowing them to ‘hide in plain sight’.

Scientists at the University of Bristol carried out two experiments to find out whether shiny or dull beetles were more likely to be eaten by birds.

The iridescent beetles were more than twice as likely to survive against predation by birds compared to non-iridescent beetles. 

And when humans were asked to hunt for beetles, they only managed to find about 17 per cent of the iridescent beetles, as opposed to spotting nearly 80 per cent of some of the dull varieties. 

A jewel beetle  Credit: Alamy 

Dr Karin Kjernsmo, an evolutionary and behavioural ecologist at the University of Bristol and first author on the study, said: “Our study is the first solid evidence for the idea that iridescence can work as highly-effective form of camouflage, and ultimately this could explain why iridescence has evolved in so many different species of animals.”

The wings of a jewel beetle can change colour depending on the angle from which they are viewed, creating a shiny, rainbow-like effect seen in everyday objects such as a CD or soap bubbles.

Dr Kjernsmo said this is because iridescence has a ‘masking ability’ that creates the ‘illusion of inconsistent features and depth’ which confuses potential predators.

The team believes there may be other species in the animal kingdom with iridescent camouflage.

Dr Kjernsmo said: “We don't for a minute imagine that the effect is something unique to jewel beetles; indeed, we'd be disappointed if it was.

“If we found that these beetles could be concealed by their colours, it increases the chances that many iridescent species could be using their colours this way.”

The findings are published in the journal Current Biology.