The U.S. Air Force can send out a drone in the future and enemies will most likely mistake it for a bird perched on trees, wires, or fences. Vishwa Robotics, based in Massachusetts, has developed a prototype of robotic legs that can be added to small quadcopter drones of the U.S. Air Force. The legs are a great addition for a drone, which is not designed for smooth landings but essentially rely on luck to land safely after a mission.

The robotic legs is equipped with a motorized claw that are very sharp and capable of gripping surfaces tightly. This helps the drone stay upright while watching a target area from afar.

Vishwa Robotics founder Bhargav Gajjar, who is a research fellow at MIT and also works as an aerospace engineer for the Space Robotics Corporation, has designed the robotic legs. The legs also serve as the shock absorbers of the spy-machine, just like in real birds. In tight or indoor spaces, the legs can also help the drone walk around.

"Gajjar studied dozens of bird species and recorded their landings using a high-speed camera. His drone's legs are based on those of the American kestrel," the New Scientist blog reported. American Kestrel is the smallest falcon found in North America. The sparrow hawk, as it is colloquially called, hunts by scanning the ground for food while perched from a tree or by hovering above potential targets.

The drone of the Air Force comes equipped with camera to help its operator control its flight and find a suitable landing surface. To land, the drone must be in a controlled stall.

In the video posted on Monday by New Scientist, the quadcopter flies onto a branch using its motors, grips the branch, and turns off its engine. This way, the drone can stay in place, watch its target, and still have enough power to go back to its base.

Aside from playing the role of a stealthy spy, the drone can also be used during natural disasters to help search for survivors in a flooded area or help establish emergency communications network. It can also help survey areas prior to a military attack or scan an area that are deemed hazardous for humans.

In an interview with Harris Communications in 2011, Gajjar shared his clear vision of what he wanted to achieve. "Gajjar explains, most drones are the size of automobiles, which means they can easily be seen and shot down. He and his team are currently developing designs for the birds-which will be made to look like species native to particular areas of the world. Operators wearing special goggles will be able to see what the 'birds' see and to guide the birds' movement-having them walk, fly and perch-from miles away. Vishwa's robotic birds hold larger batteries than recently publicized robotic hummingbirds and, thus, can be used for longer periods of time than the tinier drones," the blog post read.