Research reveals sneaky seagulls change the shape of their wings to steal food

By Mark Waghorn via SWNS

Pesky seagulls steal our french fries by changing the shape of their wings, according to new research.

Pesky seagulls steal our chips by changing the shape of their wings, according to new research.

It helps the scavengers negotiate sudden gusts or other disturbances.

Scientists say the discovery could lead to more efficient aircraft - from drones to passenger jets.

People have been fascinated by bird flight for centuries. How they remain so agile in the air even stumped Leonardo Da Vinci.

Lead author Dr. Christina Harvey, of the University of California, Davis, said: "Birds easily perform challenging maneuvers and they're adaptable.

"So what exactly about their flight is most useful to implement in future aircraft?"

She began studying gulls in Canada as a master's student in zoology at the University of British Columbia after earning a bachelor's degree in mechanical engineering.

Dr. Harvey said: "Gulls are very common and easy to find - and they're really impressive gliders."

The birds are renowned for stealing food. They are even capable of snatching ice cream out of unsuspecting tourists' hands.

Dr. Harvey and colleagues used 3-D printed models of gulls and gull wings in a wind tunnel in a lab at the University of Michigan.

Computer simulations of inertial forces showed how the creatures achieve stability while falling or rising through the air.

They react to perturbations in their long axis by adjusting wrist and elbow joints - and morphing the shape of the wings.

The US team was able to predict how rapidly they can recover from any deviation - usually caused by wind. like a gust.

It also shed fresh light on their "controllable range" - and applies the dynamics to modern-day aircraft.

Dr. Harvey said: "The flight qualities analysis asks: if you built an aircraft exactly like a gull, would a human be able to fly it?"

As uncrewed aerial vehicles, or drones, become more widely used, they need to be able to navigate complex urban environments - something birds do very well.

A deeper understanding of bird flight could help improve drone designs for various uses.

It builds on a study analyzing the flight dynamics of 22 bird species reported by the same group in March.

They developed equations to describe birds' inertial properties such as the center of gravity and the neutral point where the forces can be consistently modeled.

Previous research has tended to focus on aerodynamics - how air moves around a bird
Aircraft are typically designed to be stable or unstable.

The latter applies to highly maneuverable machines. The former return to steady flight when pushed up by a wind gust - benefitting an airliner but not a jet fighter.

Dr. Harvey showed almost all species were capable of both - and use wing movements to shift between each mode.

At UC Davis she hopes to collaborate with other campus researchers including the California Raptor Center and researchers working on insect flight at the College of Biological Sciences.

She said: "There are so many open questions about bird flight. I'm looking forward to seeing what else is out there to discover."

Leonardo da Vinci observed our feathered friends in the hills outside Florence where he lived. His 1505 Codex on the Flight of Birds is held at the Royal Library of Turin.

It begins with an examination of their flight behavior - and proposes mechanisms for flight by machines.

Dr. Harvey's latest findings are in Proceedings of the National Academy of Sciences.