The ultimate hide-and-seek champion

Carleton researcher studies camouflage in moths…if he can find them first

By Calvin Miller and Amy Thatcher

A speckled moth flutters past your nose before darting into a cluster of tall oaks. You watch it flip and flit, tracing its spiralling movements until it settles on a tree and suddenly disappears.

But something more is going on. The patchy patterns on its papery wings match the oak tree’s bark perfectly. After landing on the tree, wings folded, the moth begins a dance. It shifts left, then right, before rotating its body to match the grain of the tree’s bark. And just like that it’s gone.

A red underwing moth rests on a silver birch tree trunk. Copyright Richard Webster.

“There’s a difference between seeing, and seeing and recognizing,” says Richard Webster, a researcher at Carleton University in Ottawa.

He is examining a special type of moth camouflage: disruptive colouration. Unlike traditional concealing camouflage where the subject blends seamlessly into the background, disruptive camouflage tricks the eye into not seeing it.

His research piqued the interest of the Canadian military, prompting the Department of National Defence to invite Webster to give a talk about the subject.

The military could use these findings to better mask everything from soldiers to helicopters.

Webster sees the value in studying animal appearances and behaviours, specifically disruptive colouration.

“For a long time its been overlooked by other areas of animal colouration,” he says. “It’s only now that we’re starting to realize all the amazing adaptations around concealment and deception.”

For an in-depth look at Webster’s research, listen below.

In the animal kingdom different types of camouflage help both predator and prey survive.

By using eye-tracking technology, he monitored how long it took participants to find a moth hidden in a photo. Typically it took the participants three to 15 seconds to register the moth’s location.

“Targets with broken up edges—just like moths in the real world—were more concealed because although they were being found quite often, they were being overlooked and misclassified as part of the background,” says Webster.

But camouflage isn’t just about colouration. Changku Kang, a post-doctoral student at Carleton University studies how moths position themselves on trees to blend in more effectively.

“I wondered which cues they use to orient themselves on the tree trunks,” says Kang.

He found that moths use both tactile cues and eyesight to find the perfect hidey-hole to avoid dangerous predators. In order to survive, many prey species have to constantly develop new ways of blending in.

Source: Changku Kang

“Moths are just snacks,” says Kang. “If birds or other predatory species find the moth, they’re going to eat it.”

As prey develop better ways of hiding, hunters evolve as well. Hypersensitive vision, keen sense of smell, and precise hearing abilities are some of the ways predators keep up with their evolving meals.

“Camouflage is a great lens through which to study how the visual system has evolved,” says Webster. “Maybe this arms race between predator and prey and how they deploy camouflage, has forced animals to develop more advanced visual systems.”

Webster recognizes the wide range of human applications for his research. Studying camouflage can benefit not only the military, but also average citizens. He suggests using disruptive colouration to mask the harsh lines of buildings in National Parks.