Feathers could have developed on dinosaurs to frighten and flush out prey earlier than they have been used for flight, say researchers who constructed a winged robotic and used it to scare grasshoppers.

Pennaceous feathers, that are the stiff, non-downy feathers with a central quill, are seen in fossils of some dinosaurs resembling Caudipteryx, which lived about 124 million years in the past. These dinosaurs had wings that weren’t robust sufficient for flight, so it’s unclear how they have been used.

Jinseok Park at Seoul Nationwide College, South Korea, and his colleagues hypothesised that they have been used to startle prey into fleeing from hiding locations, in order that they could possibly be caught extra simply. This “flush-pursuit” searching technique is utilized by fashionable birds together with the higher roadrunner (Geococcyx californianus) and the northern mockingbird (Mimus polyglottos).

To check this concept, Park and his colleagues constructed a life-size robotic mannequin of Caudipteryx, nicknamed Robopteryx. The robotic approached grasshoppers, which have been a probable prey of Caudipteryx, earlier than flapping its wings. With out feathers, just below half of examined grasshoppers fled, however when the researchers connected feathers to the wings, this elevated to over 90 per cent.

The group additionally recorded the neural responses of grasshoppers whereas they have been proven an animation of Caudipteryx. Stronger exercise was seen in neurons concerned in escaping reactions when the feathers have been current within the animation than with out.

Park says the examine demonstrates that flush-pursuit searching was a probably essential issue within the evolution of pennaceous feathers on the arms and tails of dinosaurs.

“This might, in flip, result in the evolution of bigger and stiffer feathers, contributing to extra profitable pursuits and outstanding visible flush shows,” he says.

Predators with pennaceous feathers would have been capable of flush out prey from additional away, enabling them to see the trajectory of escaping creatures, says Park. That will permit them to catch prey within the air comparatively simply, he says. Even when their goal landed in vegetation, the predator may see the place it landed and comply with.

“We imagine that pennaceous feathers developed first for flush pursuing and have been used later for flight,” says Park.

However Steven Salisbury on the College of Queensland, Australia, says this clarification might be too simplistic. “It appears to me to be most unlikely {that a} construction as complicated as a pennaceous feather would evolve for such a particular behavioural position,” he says. “I’m certain there are many methods to scare grasshoppers apart from to flap some feathers at it.”

There’s most likely no single purpose why feathers developed, says Salisbury. “You possibly can have feathers to scare grasshoppers and you’ll have them to insulate and incubate eggs. They’re good for show, the stabilisation of physique place when operating and, in fact, for gliding and powered flight. Feathers assist for all kinds of issues.”