A robotic bird that is so realistic it is fooling other birds may one day also trick humans, researchers have said.

The Robo-Raven flaps, glides and dives so well it is tricking hawks and other birds and may one day be developed into a spy drone that will trick humans.

The Robo-Raven mimics a bird with its fan-shaped wings and the hollow rods that comprise the fuselage. The wings flap independently of one another allowing it to perform complex manoeuvres, such as backflips, tight turns and dives.

Robo-Raven has attracted attention from birds near the test site. Some cluster around it and camouflage it, and some birds are not so welcoming.

“You can look right at it and be fooled,” said John Gerdes, a mechanical engineer with the Army Research Laboratory Vehicle Technology Directorate at Aberdeen Proving Ground in Maryland. “Once it goes more than 20 feet in the air, the motors are so quiet, it’s indistinguishable from an animal.

“It’s been attacked by a falcon on three separate occasions,” Mr Gerdes said. “Seagulls and pigeons will cluster around it, like ‘what’s this strange creature that looks like us?'"

University scientists built the Robo-Raven out of carbon fibre, Mylar foil wings and foam. They used 3-D printers to make and retool some of its strong, lightweight plastic innards. The bird weighs less than a pound.

“It gives you complicated motions without too much of a burden on the pilot and, as an Army researcher, I keep that in the back of my mind,” he said. “If you want to have a useful Army application, it has to be easy to use with a high level of functionality.”

Researchers plan to use engineering to better duplicate a bird’s biology and its flying movements. They aim to design a future version that can fold its wings, perch, take off on its own and capture updrafts.

On the latest version, flexible solar panels cover half of the wings. Scientists hope more efficient solar cells will become available so that the Robo-Raven can fly independently. That, in turn, would enable the bird to conduct long surveillance missions. Future versions may also include sensors that relay the bird’s position, detect chemical or biological agents or relay sound.